The blood pressure in the VEINS. It is usually measured to assess the filling PRESSURE to the HEART VENTRICLE.
The blood pressure in the central large VEINS of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
The venous pressure measured in the PORTAL VEIN.
The pressure due to the weight of fluid.
Techniques for measuring blood pressure.
The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.
Transducers that are activated by pressure changes, e.g., blood pressure.
Abnormal increase of resistance to blood flow within the hepatic PORTAL SYSTEM, frequently seen in LIVER CIRRHOSIS and conditions with obstruction of the PORTAL VEIN.
The vascular resistance to the flow of BLOOD through the CAPILLARIES portions of the peripheral vascular bed.
Pressure within the cranial cavity. It is influenced by brain mass, the circulatory system, CSF dynamics, and skull rigidity.
Veins in the neck which drain the brain, face, and neck into the brachiocephalic or subclavian veins.
The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.
The number of times the HEART VENTRICLES contract per unit of time, usually per minute.
The pressure of the fluids in the eye.
The flow of BLOOD through or around an organ or region of the body.
The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).
The vessels carrying blood away from the capillary beds.
Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.
The blood pressure as recorded after wedging a CATHETER in a small PULMONARY ARTERY; believed to reflect the PRESSURE in the pulmonary CAPILLARIES.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.
Veins which drain the liver.
The blood pressure in the ARTERIES. It is commonly measured with a SPHYGMOMANOMETER on the upper arm which represents the arterial pressure in the BRACHIAL ARTERY.
Impaired venous blood flow or venous return (venous stasis), usually caused by inadequate venous valves. Venous insufficiency often occurs in the legs, and is associated with EDEMA and sometimes with VENOUS STASIS ULCERS at the ankle.
The circulation of BLOOD through the LIVER.
Method in which repeated blood pressure readings are made while the patient undergoes normal daily activities. It allows quantitative analysis of the high blood pressure load over time, can help distinguish between types of HYPERTENSION, and can assess the effectiveness of antihypertensive therapy.
Any liquid used to replace blood plasma, usually a saline solution, often with serum albumins, dextrans or other preparations. These substances do not enhance the oxygen- carrying capacity of blood, but merely replace the volume. They are also used to treat dehydration.
The measure of a BLOOD VESSEL's ability to increase the volume of BLOOD it holds without a large increase in BLOOD PRESSURE. The vascular capacitance is equal to the change in volume divided by the change in pressure.
Recording of change in the size of a part as modified by the circulation in it.
External decompression applied to the lower body. It is used to study orthostatic intolerance and the effects of gravitation and acceleration, to produce simulated hemorrhage in physiologic research, to assess cardiovascular function, and to reduce abdominal stress during childbirth.
Therapy whose basic objective is to restore the volume and composition of the body fluids to normal with respect to WATER-ELECTROLYTE BALANCE. Fluids may be administered intravenously, orally, by intermittent gavage, or by HYPODERMOCLYSIS.
The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.
The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.
A short thick vein formed by union of the superior mesenteric vein and the splenic vein.
The position or attitude of the body.
The constant checking on the state or condition of a patient during the course of a surgical operation (e.g., checking of vital signs).
An abnormally low volume of blood circulating through the body. It may result in hypovolemic shock (see SHOCK).
Manometric pressure of the CEREBROSPINAL FLUID as measured by lumbar, cerebroventricular, or cisternal puncture. Within the cranial cavity it is called INTRACRANIAL PRESSURE.
The circulation of blood through the BLOOD VESSELS supplying the abdominal VISCERA.
Devices for the compression of a blood vessel by application around an extremity to control the circulation and prevent the flow of blood to or from the distal area. (From Dorland, 28th ed)
Liver disease in which the normal microcirculation, the gross vascular anatomy, and the hepatic architecture have been variably destroyed and altered with fibrous septa surrounding regenerated or regenerating parenchymal nodules.
The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.
Dilated blood vessels in the ESOPHAGUS or GASTRIC FUNDUS that shunt blood from the portal circulation (PORTAL SYSTEM) to the systemic venous circulation. Often they are observed in individuals with portal hypertension (HYPERTENSION, PORTAL).
The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.
Elements of limited time intervals, contributing to particular results or situations.
The pressure within a CARDIAC VENTRICLE. Ventricular pressure waveforms can be measured in the beating heart by catheterization or estimated using imaging techniques (e.g., DOPPLER ECHOCARDIOGRAPHY). The information is useful in evaluating the function of the MYOCARDIUM; CARDIAC VALVES; and PERICARDIUM, particularly with simultaneous measurement of other (e.g., aortic or atrial) pressures.
Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.
A system of vessels in which blood, after passing through one capillary bed, is conveyed through a second set of capillaries before it returns to the systemic circulation. It pertains especially to the hepatic portal system.
The inferior part of the lower extremity between the KNEE and the ANKLE.
Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless of pharmacological mechanism. Among the antihypertensive agents are DIURETICS; (especially DIURETICS, THIAZIDE); ADRENERGIC BETA-ANTAGONISTS; ADRENERGIC ALPHA-ANTAGONISTS; ANGIOTENSIN-CONVERTING ENZYME INHIBITORS; CALCIUM CHANNEL BLOCKERS; GANGLIONIC BLOCKERS; and VASODILATOR AGENTS.
Abnormally low BLOOD PRESSURE that can result in inadequate blood flow to the brain and other vital organs. Common symptom is DIZZINESS but greater negative impacts on the body occur when there is prolonged depravation of oxygen and nutrients.
The posture of an individual lying face up.
The continuous measurement of physiological processes, blood pressure, heart rate, renal output, reflexes, respiration, etc., in a patient or experimental animal; includes pharmacologic monitoring, the measurement of administered drugs or their metabolites in the blood, tissues, or urine.
Starches that have been chemically modified so that a percentage of OH groups are substituted with 2-hydroxyethyl ether groups.
Posture while lying with the head lower than the rest of the body. Extended time in this position is associated with temporary physiologic disturbances.
The pressure required to prevent the passage of solvent through a semipermeable membrane that separates a pure solvent from a solution of the solvent and solute or that separates different concentrations of a solution. It is proportional to the osmolality of the solution.
A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.
A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures.
The vein accompanying the femoral artery in the same sheath; it is a continuation of the popliteal vein and becomes the external iliac vein.
Distensibility measure of a chamber such as the lungs (LUNG COMPLIANCE) or bladder. Compliance is expressed as a change in volume per unit change in pressure.
A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.
Enlarged and tortuous VEINS.
Solutions having the same osmotic pressure as blood serum, or another solution with which they are compared. (From Grant & Hackh's Chemical Dictionary, 5th ed & Dorland, 28th ed)
An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)
Procedure in which patients are induced into an unconscious state through use of various medications so that they do not feel pain during surgery.
A response by the BARORECEPTORS to increased BLOOD PRESSURE. Increased pressure stretches BLOOD VESSELS which activates the baroreceptors in the vessel walls. The net response of the CENTRAL NERVOUS SYSTEM is a reduction of central sympathetic outflow. This reduces blood pressure both by decreasing peripheral VASCULAR RESISTANCE and by lowering CARDIAC OUTPUT. Because the baroreceptors are tonically active, the baroreflex can compensate rapidly for both increases and decreases in blood pressure.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.
The hollow, muscular organ that maintains the circulation of the blood.
The act of constricting.
The venous trunk which returns blood from the head, neck, upper extremities and chest.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
Skin breakdown or ulceration caused by VARICOSE VEINS in which there is too much hydrostatic pressure in the superficial venous system of the leg. Venous hypertension leads to increased pressure in the capillary bed, transudation of fluid and proteins into the interstitial space, altering blood flow and supply of nutrients to the skin and subcutaneous tissues, and eventual ulceration.
The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
The vein formed by the union of the anterior and posterior tibial veins; it courses through the popliteal space and becomes the femoral vein.
Blocking of a blood vessel by air bubbles that enter the circulatory system, usually after TRAUMA; surgical procedures, or changes in atmospheric pressure.
Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.
The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs.
Part of the arm in humans and primates extending from the ELBOW to the WRIST.
Short thick veins which return blood from the kidneys to the vena cava.
A procedure in which total right atrial or total caval blood flow is channeled directly into the pulmonary artery or into a small right ventricle that serves only as a conduit. The principal congenital malformations for which this operation is useful are TRICUSPID ATRESIA and single ventricle with pulmonary stenosis.
The circulation of the BLOOD through the LUNGS.
A local anesthetic of the ester type that has a rapid onset of action and a longer duration of action than procaine hydrochloride. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1017)
The distal extremity of the leg in vertebrates, consisting of the tarsus (ANKLE); METATARSUS; phalanges; and the soft tissues surrounding these bones.
Placement of an intravenous CATHETER in the subclavian, jugular, or other central vein.
The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.
Excessive accumulation of extravascular fluid in the lung, an indication of a serious underlying disease or disorder. Pulmonary edema prevents efficient PULMONARY GAS EXCHANGE in the PULMONARY ALVEOLI, and can be life-threatening.
The hemodynamic and electrophysiological action of the RIGHT ATRIUM.
The vessels carrying blood away from the heart.
The HEART and the BLOOD VESSELS by which BLOOD is pumped and circulated through the body.
Period of contraction of the HEART, especially of the HEART VENTRICLES.
Two-phase systems in which one is uniformly dispersed in another as particles small enough so they cannot be filtered or will not settle out. The dispersing or continuous phase or medium envelops the particles of the discontinuous phase. All three states of matter can form colloids among each other.
Diversion of the flow of blood from the entrance to the right atrium directly to the pulmonary arteries, avoiding the right atrium and right ventricle (Dorland, 28th ed). This a permanent procedure often performed to bypass a congenitally deformed right atrium or right ventricle.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
Insertion of a catheter into a peripheral artery, vein, or airway for diagnostic or therapeutic purposes.
Method for determining the circulating blood volume by introducing a known quantity of foreign substance into the blood and determining its concentration some minutes later when thorough mixing has occurred. From these two values the blood volume can be calculated by dividing the quantity of injected material by its concentration in the blood at the time of uniform mixing. Generally expressed as cubic centimeters or liters per kilogram of body weight.
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
Treatment process involving the injection of fluid into an organ or tissue.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
A pathological condition manifested by failure to perfuse or oxygenate vital organs.
A vein which arises from the right ascending lumbar vein or the vena cava, enters the thorax through the aortic orifice in the diaphragm, and terminates in the superior vena cava.
Bleeding in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.
Patient care procedures performed during the operation that are ancillary to the actual surgery. It includes monitoring, fluid therapy, medication, transfusion, anesthesia, radiography, and laboratory tests.
FIBROSIS of the hepatic parenchyma due to chronic excess ALCOHOL DRINKING.
Maintenance of blood flow to an organ despite obstruction of a principal vessel. Blood flow is maintained through small vessels.
The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
A highly specific (Leu-Leu) endopeptidase that generates ANGIOTENSIN I from its precursor ANGIOTENSINOGEN, leading to a cascade of reactions which elevate BLOOD PRESSURE and increase sodium retention by the kidney in the RENIN-ANGIOTENSIN SYSTEM. The enzyme was formerly listed as EC 3.4.99.19.
A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (VENTRICULAR DYSFUNCTION), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as MYOCARDIAL INFARCTION.
The condition of an anatomical structure's being constricted beyond normal dimensions.
Surgical venous shunt between the portal and systemic circulation to effect decompression of the portal circulation. It is performed primarily in the treatment of bleeding esophageal varices resulting from portal hypertension. Types of shunt include portacaval, splenorenal, mesocaval, splenocaval, left gastric-caval (coronary-caval), portarenal, umbilicorenal, and umbilicocaval.
Drugs used to cause dilation of the blood vessels.
Stable cesium atoms that have the same atomic number as the element cesium, but differ in atomic weight. Cs-133 is a naturally occurring isotope.
The circulation of blood through the BLOOD VESSELS of the BRAIN.
A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.
The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.
The clear, watery fluid which fills the anterior and posterior chambers of the eye. It has a refractive index lower than the crystalline lens, which it surrounds, and is involved in the metabolism of the cornea and the crystalline lens. (Cline et al., Dictionary of Visual Science, 4th ed, p319)
Measurement of oxygen and carbon dioxide in the blood.
The circulation of the BLOOD through the MICROVASCULAR NETWORK.
The rhythmical expansion and contraction of an ARTERY produced by waves of pressure caused by the ejection of BLOOD from the left ventricle of the HEART as it contracts.
The interstitial fluid that is in the LYMPHATIC SYSTEM.
A ubiquitous sodium salt that is commonly used to season food.
A potent natriuretic and vasodilatory peptide or mixture of different-sized low molecular weight PEPTIDES derived from a common precursor and secreted mainly by the HEART ATRIUM. All these peptides share a sequence of about 20 AMINO ACIDS.
Placement of a balloon-tipped catheter into the pulmonary artery through the antecubital, subclavian, and sometimes the femoral vein. It is used to measure pulmonary artery pressure and pulmonary artery wedge pressure which reflects left atrial pressure and left ventricular end-diastolic pressure. The catheter is threaded into the right atrium, the balloon is inflated and the catheter follows the blood flow through the tricuspid valve into the right ventricle and out into the pulmonary artery.
Veins draining the cerebrum.
The circulation of blood through the CORONARY VESSELS of the HEART.
Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.
Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).
Pathological elevation of intra-abdominal pressure (>12 mm Hg). It may develop as a result of SEPSIS; PANCREATITIS; capillary leaks, burns, or surgery. When the pressure is higher than 20 mm Hg, often with end-organ dysfunction, it is referred to as abdominal compartment syndrome.
Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.
Excision of all or part of the liver. (Dorland, 28th ed)
Measurement of the pressure or tension of liquids or gases with a manometer.
The hemodynamic and electrophysiological action of the HEART ATRIA.
Loss of blood during a surgical procedure.
A non-selective beta-adrenergic antagonist with a long half-life, used in cardiovascular disease to treat arrhythmias, angina pectoris, and hypertension. Nadolol is also used for MIGRAINE DISORDERS and for tremor.
The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.
Symptoms of cerebral hypoperfusion or autonomic overaction which develop while the subject is standing, but are relieved on recumbency. Types of this include NEUROCARDIOGENIC SYNCOPE; POSTURAL ORTHOSTATIC TACHYCARDIA SYNDROME; and neurogenic ORTHOSTATIC HYPOTENSION. (From Noseworthy, JH., Neurological Therapeutics Principles and Practice, 2007, p2575-2576)
The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
A system of organs and tissues that process and transport immune cells and LYMPH.
The period of care beginning when the patient is removed from surgery and aimed at meeting the patient's psychological and physical needs directly after surgery. (From Dictionary of Health Services Management, 2d ed)
The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
Reduction of blood viscosity usually by the addition of cell free solutions. Used clinically (1) in states of impaired microcirculation, (2) for replacement of intraoperative blood loss without homologous blood transfusion, and (3) in cardiopulmonary bypass and hypothermia.
The vein which drains the foot and leg.
The property of blood capillary ENDOTHELIUM that allows for the selective exchange of substances between the blood and surrounding tissues and through membranous barriers such as the BLOOD-AIR BARRIER; BLOOD-AQUEOUS BARRIER; BLOOD-BRAIN BARRIER; BLOOD-NERVE BARRIER; BLOOD-RETINAL BARRIER; and BLOOD-TESTIS BARRIER. Small lipid-soluble molecules such as carbon dioxide and oxygen move freely by diffusion. Water and water-soluble molecules cannot pass through the endothelial walls and are dependent on microscopic pores. These pores show narrow areas (TIGHT JUNCTIONS) which may limit large molecule movement.
Deliberate introduction of air into the peritoneal cavity.
Pathological conditions in the INTESTINES that are characterized by the gastrointestinal loss of serum proteins, including SERUM ALBUMIN; IMMUNOGLOBULINS; and at times LYMPHOCYTES. Severe condition can result in HYPOGAMMAGLOBULINEMIA or LYMPHOPENIA. Protein-losing enteropathies are associated with a number of diseases including INTESTINAL LYMPHANGIECTASIS; WHIPPLE'S DISEASE; and NEOPLASMS of the SMALL INTESTINE.
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
The venous trunk of the upper limb; a continuation of the basilar and brachial veins running from the lower border of the teres major muscle to the outer border of the first rib where it becomes the subclavian vein.
Application of a ligature to tie a vessel or strangulate a part.
A technique of respiratory therapy, in either spontaneously breathing or mechanically ventilated patients, in which airway pressure is maintained above atmospheric pressure throughout the respiratory cycle by pressurization of the ventilatory circuit. (On-Line Medical Dictionary [Internet]. Newcastle upon Tyne(UK): The University Dept. of Medical Oncology: The CancerWEB Project; c1997-2003 [cited 2003 Apr 17]. Available from: http://cancerweb.ncl.ac.uk/omd/)
Treatment of varicose veins, hemorrhoids, gastric and esophageal varices, and peptic ulcer hemorrhage by injection or infusion of chemical agents which cause localized thrombosis and eventual fibrosis and obliteration of the vessels.
Volume of PLASMA in the circulation. It is usually measured by INDICATOR DILUTION TECHNIQUES.
Diversion of the flow of blood from the entrance of the right atrium directly to the aorta (or femoral artery) via an oxygenator thus bypassing both the heart and lungs.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.
Drugs used to cause constriction of the blood vessels.
Compression of the heart by accumulated fluid (PERICARDIAL EFFUSION) or blood (HEMOPERICARDIUM) in the PERICARDIUM surrounding the heart. The affected cardiac functions and CARDIAC OUTPUT can range from minimal to total hemodynamic collapse.
Procedure in which an anesthetic is injected into the epidural space.
Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.
Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.
The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.
The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Ratings that express, in numerical values, the degree of impairment or abnormality in the function of specific organs.
An increase in the excretion of URINE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The main trunk of the systemic arteries.
An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.
Vein formed by the union (at the hilus of the spleen) of several small veins from the stomach, pancreas, spleen and mesentery.
A change in cardiovascular function resulting in a reduction in BLOOD VOLUME, and reflex DIURESIS. It occurs frequently after actual or simulated WEIGHTLESSNESS.
The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
Increased VASCULAR RESISTANCE in the PULMONARY CIRCULATION, usually secondary to HEART DISEASES or LUNG DISEASES.
Measurement of light given off by fluorescein in order to assess the integrity of various ocular barriers. The method is used to investigate the blood-aqueous barrier, blood-retinal barrier, aqueous flow measurements, corneal endothelial permeability, and tear flow dynamics.
The hemodynamic and electrophysiological action of the right HEART VENTRICLE.
The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.
A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater omentum.
Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)
The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance.
Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety.
A condition that occurs when the obstruction of the thin-walled SUPERIOR VENA CAVA interrupts blood flow from the head, upper extremities, and thorax to the RIGHT ATRIUM. Obstruction can be caused by NEOPLASMS; THROMBOSIS; ANEURYSM; or external compression. The syndrome is characterized by swelling and/or CYANOSIS of the face, neck, and upper arms.
Sepsis associated with HYPOTENSION or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to LACTIC ACIDOSIS; OLIGURIA; or acute alteration in mental status.
A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)
The main artery of the thigh, a continuation of the external iliac artery.
Abnormal fluid accumulation in TISSUES or body cavities. Most cases of edema are present under the SKIN in SUBCUTANEOUS TISSUE.
Surgery performed on the heart.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Advanced and highly specialized care provided to medical or surgical patients whose conditions are life-threatening and require comprehensive care and constant monitoring. It is usually administered in specially equipped units of a health care facility.
An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.
The interruption or removal of any part of the vagus (10th cranial) nerve. Vagotomy may be performed for research or for therapeutic purposes.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
Radiographic visualization or recording of a vein after the injection of contrast medium.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
The restoration to life or consciousness of one apparently dead. (Dorland, 27th ed)
Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.
A vasodilator used in the treatment of ANGINA PECTORIS. Its actions are similar to NITROGLYCERIN but with a slower onset of action.
The veins that return the oxygenated blood from the lungs to the left atrium of the heart.

Effect of portal-systemic anastomosis on renal haemodynamics in cirrhosis. (1/366)

In 12 patients with portal hypertension and repeated bleedings from oesophageal varices the central haemodynamics, portal pressure, and mean renal blood flow (RBF) were investigated immediately before and two to seven months after portal-systemic shunt. Cardiac output increased significantly, whereas arterial pressure was unchanged after operation. RBF, which was initially less than in controls, did not change. As portal pressure decreased significantly, a direct portal-renal, neural, or humoral reflex mechanism does not explain the subnormal RBF in cirrhosis. As plasma volume was large and unchanged after operation a "diminished circulating plasma volume" is an unlikely explanation. Therefore, on the basis of the present observations, previously postulated causes of renal hypoperfusion in cirrhosis need revision.  (+info)

Chronic retinal vein occlusion in glaucoma. (2/366)

Asymptomatic chronic retinal vein occlusion that occurs in chronic simple glaucoma is described. The condition is characterized by marked elevation of retinal vein pressure with collateral vessels and vein loops at the optic disc in cases of central vein occlusion, or retinal veno-venous anastomoses along a horizontal line temporal and nasal to the disc in hemisphere vein occlusion. No patient had visible arterial changes, capillary closure, fluorescein leakage, or haemorrhages. The vein occlusion was not limited to "end stage" glaucoma. The role of increased intraocular pressure and glaucomatous enlargement of the optic cup with retinal vein distortion in the pathogenesis of the condition was stressed. Follow-up of these patients revealed persistence of the retinal vein occlusion shown by elevated retinal vein pressures. This would reduce effective perfusion of the inner retina and optic disc and may affect the long-term visual prognosis.  (+info)

Upright posture reduces forearm blood flow early in exercise. (3/366)

The hypothesis that upright posture could modulate forearm blood flow (FBF) early in exercise was tested in six subjects. Both single (2-s duration) and repeated (1-s work/2-s rest cadence for 12 contractions) handgrip contractions (12 kg) were performed in the supine and 70 degrees head-up tilt (HUT) positions. The arm was maintained at heart level to diminish myogenic effects. Baseline brachial artery diameters were assessed at rest in each position. Brachial artery mean blood velocity (MBV; Doppler) and mean arterial pressure (MAP) (Finapres) were measured continuously to calculate FBF and vascular conductance. MAP was not changed with posture. Antecubital venous pressure (Pv) was reduced in HUT (4.55 +/- 1.3 mmHg) compared with supine (11.3 +/- 1.9 mmHg) (P < 0.01). For the repeated contractions, total excess FBF (TEF) was reduced in the HUT position compared with supine (P < 0.02). With the single contractions, peak FBF, peak vascular conductance, and TEF during 30 s after release of the contraction were reduced in the HUT position compared with supine (P < 0.01). Sympathetic blockade augmented the FBF response to a single contraction in HUT (P < 0.05) and tended to increase this response while supine (P = 0.08). However, sympathetic blockade did not attenuate the effect of HUT on peak FBF and TEF after the single contractions. Raising the arm above heart level while supine, to diminish Pv, resulted in FBF dynamics that were similar to those observed during HUT. Alternatively, lowering the arm while in HUT to restore Pv to supine levels restored the peak FBF and vascular conductance responses, but not TEF response, after a single contraction. It was concluded that upright posture diminishes the hyperemic response early in exercise. The data demonstrate that sympathetic constriction restrains the hyperemic response to a single contraction but does not modulate the postural reduction in postcontraction hyperemia. Therefore, the attenuated blood flow response in the HUT posture was largely related to factors associated with diminished venous pressures and not sympathetic vasoconstriction.  (+info)

Studies in calf venous pump function utilizing a two-valve experimental model. (4/366)

OBJECTIVES: to explore the hydrodynamic mechanisms involved in the regulation of ambulatory venous pressure. DESIGN: an experimental model of calf venous pump was constructed with collapsible tubes and valves. MATERIAL: the model consisted of a conduit and a pump with an intervening competent valve. Another valve that could allow reflux into the pump was mounted above the pump. METHODS: conduit pressure and recovery times were monitored under conditions of different degrees of ejection fraction and reflux into the pump. Model variables included using poorly compliant tubes for the pump, the conduit and for both the pump and conduit. RESULTS: the latex tube exhibited a non-linear volume-pressure relationship and a bi-modal regimen of compliance. This bestowed pressure-buffering properties. Ambulatory venous hypertension resulted when reflux beyond buffering capacity occurred. Substituting less compliant PTFE for latex at the pump had a relatively minor effect on post-ejection pressure and recovery times. Using PTFE at the conduit had a profound but divergent effect on both of these parameters. Conduit capacitance reduction had a similar effect. CONCLUSION: conduit elastance plays a significant role in the regulation of ambulatory venous pressure in this experimental model. The hydrodynamic principles illustrated by the model may enhance our understanding of the human calf venous pump.  (+info)

Responses of group III and IV muscle afferents to distension of the peripheral vascular bed. (5/366)

This study was undertaken to test the hypothesis that group III and IV afferents with endings in skeletal muscle signal the distension of the peripheral vascular network. The responses of these slowly conducting afferents to pharmacologically induced vasodilation and to acute obstruction of the venous drainage of the hindlimbs were studied in barbiturate-anesthetized cats. Afferent impulses arising from endings in the triceps surae muscles were recorded from the L(7) and S(1) dorsal roots. Fifteen of the 48 group IV and 3 of the 19 group III afferents tested were stimulated by intra-aortic injections of papaverine (2-2.5 mg/kg). Sixty-two percent of the afferents that responded to papaverine also responded to isoproterenol (50 microg/kg). Seven of the 36 group IV and 2 of the 12 group III afferents tested were excited by acute distension of the hindlimb venous system. Four of the seven group IV afferents responding to venous distension also responded to papaverine (57 vs. 13% for the nonresponding). Finally, we observed that most of the group IV afferents that were excited by dynamic contractions of the triceps surae muscles also responded either to venous distension or to vasodilatory agents. These results are consistent with the histological findings that a large number of group IV endings have their receptive fields close to the venules and suggest that they can be stimulated by the deformation of these vascular structures when peripheral conductance increases. Moreover, such a mechanism offers the possibility of encoding both the effects of muscle contraction through intramuscular pressure changes and the distension of the venular system, thereby monitoring the activity of the veno-muscular pump.  (+info)

Restrictive pericarditis. (6/366)

BACKGROUND: Pericardial thickening is an uncommon complication of cardiac surgery. OBJECTIVES: To study pericardial thickening as the cause of severe postoperative venous congestion. SUBJECTS: Two men, one with severe aortic stenosis and single coronary artery disease, and one with coronary artery disease after an old inferior infarction. Both had coronary artery bypass grafting surgery. METHODS: Magnetic resonance imaging (MRI), Doppler echocardiography, and cardiac catheterisation. RESULTS: Venous pressure was raised in both patients. MRI showed mildly thickened pericardium, and cardiac catheterisation indicated diastolic equalization of pressures in the four chambers. Jugular venous pulse showed a dominant "Y" descent coinciding with early diastolic flow in the superior vena cava, and mitral and tricuspid Doppler forward flow proved restrictive physiology. The clinical background suggested pericardial disease so both patients had pericardiectomy. This proved the pericardium to be thickened; the extent of fibrosis also involved the epicardium. CONCLUSIONS: Although rare, restrictive pericarditis (restrictive ventricular physiology resulting from pericardial disease) should be considered to be a separate diagnostic entity because its pathological basis and treatment are different from intrinsic myocardial disease. This diagnosis may be confirmed by standard investigational techniques or may require diagnostic thoracotomy.  (+info)

Effects of protamine on nitric oxide level in the pulmonary circulation. (7/366)

Protamine reversal of heparin anticoagulation often causes systemic hypotension by releasing nitric oxide (NO) from vascular endothelium. We investigated the hypothesis that protamine prevents severe pulmonary vasoconstriction by increasing NO. Twenty patients undergoing elective coronary artery bypass graft surgery were included in the study. Nitrite and nitrate levels--as end-metabolites of NO--were measured in blood samples obtained before and after protamine administration. Mean arterial pressure, heart rate, mean pulmonary artery pressure, central venous pressure and left atrial pressure were noted as hemodynamic data. Nitrite levels were 4.64 +/- 0.67 mumol in the right atrium and 4.84 +/- 0.95 mumol in the left atrium before protamine administration. The difference was insignificant statistically. These measurements were 4.85 +/- 0.92 in the right atrium and 5.28 +/- 0.66 mumol in the left atrium after protamine administration. This increase was significant (p < 0.05). The measurements of nitrate levels were completely parallel with those of nitrite. Mean arterial pressures were 78.9 +/- 7.59 mm-Hg before protamine and 74.1 +/- 8.55 mm-Hg after protamine (p = 0.03). The changes in other hemodynamic parameters were not significant. Protamine augments NO production and prevents the pulmonary circulation from possible vasoconstriction.  (+info)

The effect of pregnancy on the lower-limb venous system of women with varicose veins. (8/366)

OBJECTIVES: to assess the effect of pregnancy on the lower-limb venous system of women with varicose veins. Design a longitudinal prospective study of 11 pregnant women, with varicose vein disease. METHODS: eleven pregnant women with varicose veins were recruited as part of a larger study. Veins were assessed in both lower limbs using colour-flow duplex scanning at a 75 degrees head-up tilt. The diameter and velocity and duration of reflux were measured in each vein at 12, 20, 26, 34, 38 weeks gestation and 6 weeks postpartum. RESULTS: eleven women had reflux and varicose veins demonstrated at first scan. All veins dilated with increasing gestation. This was maximal in the superficial system, reaching significance (p+info)

Venous pressure is the pressure exerted on the walls of a vein, which varies depending on several factors such as the volume and flow of blood within the vein, the contractile state of the surrounding muscles, and the position of the body. In clinical settings, venous pressure is often measured in the extremities (e.g., arms or legs) to assess the functioning of the cardiovascular system.

Central venous pressure (CVP) is a specific type of venous pressure that refers to the pressure within the large veins that enter the right atrium of the heart. CVP is an important indicator of right heart function and fluid status, as it reflects the amount of blood returning to the heart and the ability of the heart to pump it forward. Normal CVP ranges from 0 to 8 mmHg (millimeters of mercury) in adults.

Elevated venous pressure can be caused by various conditions such as heart failure, obstruction of blood flow, or fluid overload, while low venous pressure may indicate dehydration or blood loss. Accurate measurement and interpretation of venous pressure require specialized equipment and knowledge, and are typically performed by healthcare professionals in a clinical setting.

Central venous pressure (CVP) is the blood pressure measured in the large veins that enter the right atrium of the heart. It reflects the amount of blood returning to the heart and the ability of the heart to pump it effectively. CVP is used as an indicator of a person's intravascular volume status, cardiac function, and overall hemodynamic performance. The measurement is taken using a central venous catheter placed in a large vein such as the internal jugular or subclavian vein. Normal CVP values range from 0 to 8 mmHg (millimeters of mercury) in adults when measured at the level of the right atrium.

In medical terms, pressure is defined as the force applied per unit area on an object or body surface. It is often measured in millimeters of mercury (mmHg) in clinical settings. For example, blood pressure is the force exerted by circulating blood on the walls of the arteries and is recorded as two numbers: systolic pressure (when the heart beats and pushes blood out) and diastolic pressure (when the heart rests between beats).

Pressure can also refer to the pressure exerted on a wound or incision to help control bleeding, or the pressure inside the skull or spinal canal. High or low pressure in different body systems can indicate various medical conditions and require appropriate treatment.

Blood pressure is the force exerted by circulating blood on the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and is given as two figures:

1. Systolic pressure: This is the pressure when the heart pushes blood out into the arteries.
2. Diastolic pressure: This is the pressure when the heart rests between beats, allowing it to fill with blood.

Normal blood pressure for adults is typically around 120/80 mmHg, although this can vary slightly depending on age, sex, and other factors. High blood pressure (hypertension) is generally considered to be a reading of 130/80 mmHg or higher, while low blood pressure (hypotension) is usually defined as a reading below 90/60 mmHg. It's important to note that blood pressure can fluctuate throughout the day and may be affected by factors such as stress, physical activity, and medication use.

Portal pressure, also known as portal hypertension, refers to an increase in the pressure within the portal vein, which is the large blood vessel that carries blood from the gastrointestinal tract and spleen to the liver. Normal portal pressure is usually between 5-10 mmHg.

Portal hypertension can occur as a result of various conditions that cause obstruction or narrowing of the portal vein, or increased resistance to blood flow within the liver. This can lead to the development of collateral vessels, which are abnormal blood vessels that form to bypass the blocked or narrowed vessel, and can result in complications such as variceal bleeding, ascites, and encephalopathy.

The measurement of portal pressure is often used in the diagnosis and management of patients with liver disease and portal hypertension.

Hydrostatic pressure is the pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. In medical terms, hydrostatic pressure is often discussed in relation to body fluids and tissues. For example, the hydrostatic pressure in the capillaries (tiny blood vessels) is the force that drives the fluid out of the blood vessels and into the surrounding tissues. This helps to maintain the balance of fluids in the body. Additionally, abnormal increases in hydrostatic pressure can contribute to the development of edema (swelling) in the tissues.

Blood pressure determination is the medical procedure to measure and assess the force or pressure exerted by the blood on the walls of the arteries during a heartbeat cycle. It is typically measured in millimeters of mercury (mmHg) and is expressed as two numbers: systolic pressure (the higher number, representing the pressure when the heart beats and pushes blood out into the arteries) and diastolic pressure (the lower number, representing the pressure when the heart rests between beats). A normal blood pressure reading is typically around 120/80 mmHg. High blood pressure (hypertension) is defined as a consistently elevated blood pressure of 130/80 mmHg or higher, while low blood pressure (hypotension) is defined as a consistently low blood pressure below 90/60 mmHg. Blood pressure determination is an important vital sign and helps to evaluate overall cardiovascular health and identify potential health risks.

Hemodynamics is the study of how blood flows through the cardiovascular system, including the heart and the vascular network. It examines various factors that affect blood flow, such as blood volume, viscosity, vessel length and diameter, and pressure differences between different parts of the circulatory system. Hemodynamics also considers the impact of various physiological and pathological conditions on these variables, and how they in turn influence the function of vital organs and systems in the body. It is a critical area of study in fields such as cardiology, anesthesiology, and critical care medicine.

A pressure transducer is a device that converts a mechanical force or pressure exerted upon it into an electrical signal which can be measured and standardized. In medical terms, pressure transducers are often used to measure various bodily pressures such as blood pressure, intracranial pressure, or intraocular pressure. These transducers typically consist of a diaphragm that is deflected by the pressure being measured, which then generates an electrical signal proportional to the amount of deflection. This signal can be processed and displayed in various ways, such as on a monitor or within an electronic medical record system.

Portal hypertension is a medical condition characterized by an increased pressure in the portal vein, which is the large blood vessel that carries blood from the intestines, spleen, and pancreas to the liver. Normal portal venous pressure is approximately 5-10 mmHg. Portal hypertension is defined as a portal venous pressure greater than 10 mmHg.

The most common cause of portal hypertension is cirrhosis of the liver, which leads to scarring and narrowing of the small blood vessels in the liver, resulting in increased resistance to blood flow. Other causes include blood clots in the portal vein, inflammation of the liver or bile ducts, and invasive tumors that block the flow of blood through the liver.

Portal hypertension can lead to a number of complications, including the development of abnormal blood vessels (varices) in the esophagus, stomach, and intestines, which are prone to bleeding. Ascites, or the accumulation of fluid in the abdominal cavity, is another common complication of portal hypertension. Other potential complications include encephalopathy, which is a condition characterized by confusion, disorientation, and other neurological symptoms, and an increased risk of bacterial infections.

Treatment of portal hypertension depends on the underlying cause and the severity of the condition. Medications to reduce pressure in the portal vein, such as beta blockers or nitrates, may be used. Endoscopic procedures to band or inject varices can help prevent bleeding. In severe cases, surgery or liver transplantation may be necessary.

Capillary resistance, in the context of physiology and medicine, refers to the resistance to blood flow that is offered by the small capillaries in the circulatory system. Capillaries are tiny blood vessels that connect the arteries and veins, and they play a critical role in the exchange of oxygen, nutrients, and waste products between the blood and the body's tissues.

The resistance provided by the capillaries is determined by several factors, including the diameter and length of the capillaries, as well as the viscosity of the blood that flows through them. Capillary resistance is an important factor in regulating blood flow and blood pressure throughout the body. In general, an increase in capillary resistance can lead to a decrease in blood flow and an increase in blood pressure, while a decrease in capillary resistance can have the opposite effect.

It's worth noting that the term "capillary resistance" is not commonly used in medical literature or clinical practice. Instead, physicians and researchers may use more specific terms to describe the resistance provided by different parts of the circulatory system, such as "total peripheral resistance," which refers to the resistance provided by all of the body's blood vessels excluding the heart and lungs.

Intracranial pressure (ICP) is the pressure inside the skull and is typically measured in millimeters of mercury (mmHg). It's the measurement of the pressure exerted by the cerebrospinal fluid (CSF), blood, and brain tissue within the confined space of the skull.

Normal ICP ranges from 5 to 15 mmHg in adults when lying down. Intracranial pressure may increase due to various reasons such as bleeding in the brain, swelling of the brain, increased production or decreased absorption of CSF, and brain tumors. Elevated ICP is a serious medical emergency that can lead to brain damage or even death if not promptly treated. Symptoms of high ICP may include severe headache, vomiting, altered consciousness, and visual changes.

The jugular veins are a pair of large, superficial veins that carry blood from the head and neck to the heart. They are located in the neck and are easily visible when looking at the side of a person's neck. The external jugular vein runs along the surface of the muscles in the neck, while the internal jugular vein runs within the carotid sheath along with the carotid artery and the vagus nerve.

The jugular veins are important in clinical examinations because they can provide information about a person's cardiovascular function and intracranial pressure. For example, distention of the jugular veins may indicate heart failure or increased intracranial pressure, while decreased venous pulsations may suggest a low blood pressure or shock.

It is important to note that medical conditions such as deep vein thrombosis (DVT) can also affect the jugular veins and can lead to serious complications if not treated promptly.

Vascular resistance is a measure of the opposition to blood flow within a vessel or a group of vessels, typically expressed in units of mmHg/(mL/min) or sometimes as dynes*sec/cm^5. It is determined by the diameter and length of the vessels, as well as the viscosity of the blood flowing through them. In general, a decrease in vessel diameter, an increase in vessel length, or an increase in blood viscosity will result in an increase in vascular resistance, while an increase in vessel diameter, a decrease in vessel length, or a decrease in blood viscosity will result in a decrease in vascular resistance. Vascular resistance is an important concept in the study of circulation and cardiovascular physiology because it plays a key role in determining blood pressure and blood flow within the body.

Heart rate is the number of heartbeats per unit of time, often expressed as beats per minute (bpm). It can vary significantly depending on factors such as age, physical fitness, emotions, and overall health status. A resting heart rate between 60-100 bpm is generally considered normal for adults, but athletes and individuals with high levels of physical fitness may have a resting heart rate below 60 bpm due to their enhanced cardiovascular efficiency. Monitoring heart rate can provide valuable insights into an individual's health status, exercise intensity, and response to various treatments or interventions.

Intraocular pressure (IOP) is the fluid pressure within the eye, specifically within the anterior chamber, which is the space between the cornea and the iris. It is measured in millimeters of mercury (mmHg). The aqueous humor, a clear fluid that fills the anterior chamber, is constantly produced and drained, maintaining a balance that determines the IOP. Normal IOP ranges from 10-21 mmHg, with average values around 15-16 mmHg. Elevated IOP is a key risk factor for glaucoma, a group of eye conditions that can lead to optic nerve damage and vision loss if not treated promptly and effectively. Regular monitoring of IOP is essential in diagnosing and managing glaucoma and other ocular health issues.

Regional blood flow (RBF) refers to the rate at which blood flows through a specific region or organ in the body, typically expressed in milliliters per minute per 100 grams of tissue (ml/min/100g). It is an essential physiological parameter that reflects the delivery of oxygen and nutrients to tissues while removing waste products. RBF can be affected by various factors such as metabolic demands, neural regulation, hormonal influences, and changes in blood pressure or vascular resistance. Measuring RBF is crucial for understanding organ function, diagnosing diseases, and evaluating the effectiveness of treatments.

Cardiac output is a measure of the amount of blood that is pumped by the heart in one minute. It is defined as the product of stroke volume (the amount of blood pumped by the left ventricle during each contraction) and heart rate (the number of contractions per minute). Normal cardiac output at rest for an average-sized adult is about 5 to 6 liters per minute. Cardiac output can be increased during exercise or other conditions that require more blood flow, such as during illness or injury. It can be measured noninvasively using techniques such as echocardiography or invasively through a catheter placed in the heart.

Veins are blood vessels that carry deoxygenated blood from the tissues back to the heart. They have a lower pressure than arteries and contain valves to prevent the backflow of blood. Veins have a thin, flexible wall with a larger lumen compared to arteries, allowing them to accommodate more blood volume. The color of veins is often blue or green due to the absorption characteristics of light and the reduced oxygen content in the blood they carry.

Hypertension is a medical term used to describe abnormally high blood pressure in the arteries, often defined as consistently having systolic blood pressure (the top number in a blood pressure reading) over 130 mmHg and/or diastolic blood pressure (the bottom number) over 80 mmHg. It is also commonly referred to as high blood pressure.

Hypertension can be classified into two types: primary or essential hypertension, which has no identifiable cause and accounts for about 95% of cases, and secondary hypertension, which is caused by underlying medical conditions such as kidney disease, hormonal disorders, or use of certain medications.

If left untreated, hypertension can lead to serious health complications such as heart attack, stroke, heart failure, and chronic kidney disease. Therefore, it is important for individuals with hypertension to manage their condition through lifestyle modifications (such as healthy diet, regular exercise, stress management) and medication if necessary, under the guidance of a healthcare professional.

Pulmonary wedge pressure, also known as pulmonary capillary wedge pressure (PCWP) or left heart filling pressure, is a measurement obtained during right heart catheterization. It reflects the pressure in the left atrium, which is an estimate of the diastolic pressure in the left ventricle. Normal PCWP ranges from 4 to 12 mmHg. Increased pulmonary wedge pressure can indicate heart failure or other cardiac disorders that affect the left side of the heart.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

Blood volume refers to the total amount of blood present in an individual's circulatory system at any given time. It is the combined volume of both the plasma (the liquid component of blood) and the formed elements (such as red and white blood cells and platelets) in the blood. In a healthy adult human, the average blood volume is approximately 5 liters (or about 1 gallon). However, blood volume can vary depending on several factors, including age, sex, body weight, and overall health status.

Blood volume plays a critical role in maintaining proper cardiovascular function, as it affects blood pressure, heart rate, and the delivery of oxygen and nutrients to tissues throughout the body. Changes in blood volume can have significant impacts on an individual's health and may be associated with various medical conditions, such as dehydration, hemorrhage, heart failure, and liver disease. Accurate measurement of blood volume is essential for diagnosing and managing these conditions, as well as for guiding treatment decisions in clinical settings.

The hepatic veins are blood vessels that carry oxygen-depleted blood from the liver back to the heart. There are typically three major hepatic veins - right, middle, and left - that originate from the posterior aspect of the liver and drain into the inferior vena cava just below the diaphragm. These veins are responsible for returning the majority of the blood flow from the gastrointestinal tract and spleen to the heart. It's important to note that the hepatic veins do not have valves, which can make them susceptible to a condition called Budd-Chiari syndrome, where blood clots form in the veins and obstruct the flow of blood from the liver.

Arterial pressure is the pressure exerted by the blood on the walls of the arteries during its flow through them. It is usually measured in millimeters of mercury (mmHg) and is expressed as two numbers: systolic and diastolic pressures. Systolic pressure is the higher value, representing the pressure when the heart contracts and pushes blood into the arteries. Diastolic pressure is the lower value, representing the pressure when the heart relaxes and fills with blood. A normal resting blood pressure for adults is typically around 120/80 mmHg.

Venous insufficiency is a medical condition that occurs when the veins, particularly in the legs, have difficulty returning blood back to the heart due to impaired valve function or obstruction in the vein. This results in blood pooling in the veins, leading to symptoms such as varicose veins, swelling, skin changes, and ulcers. Prolonged venous insufficiency can cause chronic pain and affect the quality of life if left untreated.

Liver circulation, also known as hepatic circulation, refers to the blood flow through the liver. The liver receives blood from two sources: the hepatic artery and the portal vein.

The hepatic artery delivers oxygenated blood from the heart to the liver, accounting for about 25% of the liver's blood supply. The remaining 75% comes from the portal vein, which carries nutrient-rich, deoxygenated blood from the gastrointestinal tract, spleen, pancreas, and gallbladder to the liver.

In the liver, these two sources of blood mix in the sinusoids, small vessels with large spaces between the endothelial cells that line them. This allows for efficient exchange of substances between the blood and the hepatocytes (liver cells). The blood then leaves the liver through the hepatic veins, which merge into the inferior vena cava and return the blood to the heart.

The unique dual blood supply and extensive sinusoidal network in the liver enable it to perform various critical functions, such as detoxification, metabolism, synthesis, storage, and secretion of numerous substances, maintaining body homeostasis.

Ambulatory Blood Pressure Monitoring (ABPM) is a non-invasive method of measuring blood pressure at regular intervals over a 24-hour period or more. This is typically done using a portable device that is worn on a belt around the waist and connected to a cuff wrapped around the upper arm. The device automatically inflates the cuff and records blood pressure readings at preset intervals, usually every 15 to 30 minutes during the day and every 30 to 60 minutes during the night.

ABPM provides valuable information about blood pressure patterns over an extended period, including how it varies throughout the day and in response to daily activities, posture changes, and sleep. This can help healthcare providers diagnose and manage hypertension more effectively, as well as assess the effectiveness of antihypertensive medications. ABPM is also useful for identifying white coat hypertension, a condition where blood pressure readings are higher in a medical setting than in daily life.

Overall, ambulatory blood pressure monitoring is an important tool in the diagnosis and management of hypertension and related cardiovascular diseases.

Plasma substitutes are fluids that are used to replace the plasma volume in conditions such as hypovolemia (low blood volume) or plasma loss, for example due to severe burns, trauma, or major surgery. They do not contain cells or clotting factors, but they help to maintain intravascular volume and tissue perfusion. Plasma substitutes can be divided into two main categories: crystalloids and colloids.

Crystalloid solutions contain small molecules that can easily move between intracellular and extracellular spaces. Examples include normal saline (0.9% sodium chloride) and lactated Ringer's solution. They are less expensive and have a lower risk of allergic reactions compared to colloids, but they may require larger volumes to achieve the same effect due to their rapid distribution in the body.

Colloid solutions contain larger molecules that tend to stay within the intravascular space for longer periods, thus increasing the oncotic pressure and helping to maintain fluid balance. Examples include albumin, fresh frozen plasma, and synthetic colloids such as hydroxyethyl starch (HES) and gelatin. Colloids may be more effective in restoring intravascular volume, but they carry a higher risk of allergic reactions and anaphylaxis, and some types have been associated with adverse effects such as kidney injury and coagulopathy.

The choice of plasma substitute depends on various factors, including the patient's clinical condition, the underlying cause of plasma loss, and any contraindications or potential side effects of the available products. It is important to monitor the patient's hemodynamic status, electrolyte balance, and coagulation profile during and after the administration of plasma substitutes to ensure appropriate resuscitation and avoid complications.

Vascular capacitance is a term used in physiology to describe the ability of blood vessels, particularly veins, to expand and accommodate changes in blood volume. It is the measure of the volume of blood that a vessel can hold for each unit increase in pressure. A larger capacitance means that the blood vessels can store more blood at lower pressures.

In simpler terms, vascular capacitance refers to the compliance or distensibility of the blood vessels. When the heart pumps blood into the arteries, some of it is immediately used by the body's tissues for various functions, while the remaining blood is stored in the veins until needed. The more compliant or distensible the veins are, the greater their capacity to store blood and maintain a relatively stable blood pressure.

Therefore, vascular capacitance plays an essential role in regulating blood pressure and ensuring adequate blood flow to various organs and tissues in the body. Factors that can affect vascular capacitance include age, overall health status, and certain medical conditions such as heart failure or cirrhosis of the liver.

Plethysmography is a non-invasive medical technique used to measure changes in volume or blood flow within an organ or body part, typically in the lungs or extremities. There are several types of plethysmography, including:

1. **Whole Body Plethysmography (WBP):** This type of plethysmography is used to assess lung function and volumes by measuring changes in pressure within a sealed chamber that contains the patient's entire body except for their head. The patient breathes normally while wearing a nose clip, allowing technicians to analyze respiratory patterns, airflow, and lung volume changes.
2. **Segmental or Local Plethysmography:** This technique measures volume or blood flow changes in specific body parts, such as the limbs or digits. It can help diagnose and monitor conditions affecting peripheral circulation, like deep vein thrombosis, arterial occlusive disease, or Raynaud's phenomenon.
3. **Impedance Plethysmography (IPG):** This non-invasive method uses electrical impedance to estimate changes in blood volume within an organ or body part. By applying a small electrical current and measuring the opposition to flow (impedance), technicians can determine variations in blood volume, which can help diagnose conditions like deep vein thrombosis or heart failure.
4. **Optical Plethysmography:** This technique uses light to measure changes in blood volume, typically in the skin or mucous membranes. By shining a light on the area and analyzing the reflected or transmitted light, technicians can detect variations in blood volume related to cardiac output, respiration, or other physiological factors.

Overall, plethysmography is an essential tool for diagnosing and monitoring various medical conditions affecting circulation, respiratory function, and organ volumes.

Lower Body Negative Pressure (LBNP) is a medical term that refers to the application of a negative pressure (below atmospheric pressure) to the lower body, while the upper body remains at normal atmospheric pressure. This is typically achieved through the use of an air-tight chamber or suit that covers the lower body from the waist down.

The negative pressure causes fluid to be drawn towards the lower body, which can simulate the effects of weightlessness or reduced gravity on the cardiovascular system. LBNP is often used in research settings to study the physiological responses to changes in gravitational forces, as well as in clinical settings to help prevent or treat various medical conditions, such as orthostatic intolerance, venous ulcers, and chronic wounds.

Fluid therapy, in a medical context, refers to the administration of fluids into a patient's circulatory system for various therapeutic purposes. This can be done intravenously (through a vein), intraosseously (through a bone), or subcutaneously (under the skin). The goal of fluid therapy is to correct or prevent imbalances in the body's fluids and electrolytes, maintain or restore blood volume, and support organ function.

The types of fluids used in fluid therapy can include crystalloids (which contain electrolytes and water) and colloids (which contain larger molecules like proteins). The choice of fluid depends on the patient's specific needs and condition. Fluid therapy is commonly used in the treatment of dehydration, shock, sepsis, trauma, surgery, and other medical conditions that can affect the body's fluid balance.

Proper administration of fluid therapy requires careful monitoring of the patient's vital signs, urine output, electrolyte levels, and overall clinical status to ensure that the therapy is effective and safe.

Air pressure, also known as atmospheric pressure, is the force exerted by the weight of air in the atmosphere on a surface. It is measured in units such as pounds per square inch (psi), hectopascals (hPa), or inches of mercury (inHg). The standard atmospheric pressure at sea level is defined as 101,325 Pa (14.7 psi/1013 hPa/29.92 inHg). Changes in air pressure can be used to predict weather patterns and are an important factor in the study of aerodynamics and respiratory physiology.

Atmospheric pressure, also known as barometric pressure, is the force per unit area exerted by the Earth's atmosphere on objects. It is measured in units of force per unit area, such as pascals (Pa), pounds per square inch (psi), or, more commonly, millimeters of mercury (mmHg).

Standard atmospheric pressure at sea level is defined as 101,325 Pa (14.7 psi) or 760 mmHg (29.92 inches of mercury). Atmospheric pressure decreases with increasing altitude, as the weight of the air above becomes less. This decrease in pressure can affect various bodily functions, such as respiration and digestion, and may require adaptation for individuals living at high altitudes. Changes in atmospheric pressure can also be used to predict weather patterns, as low pressure systems are often associated with stormy or inclement weather.

The portal vein is the large venous trunk that carries blood from the gastrointestinal tract, spleen, pancreas, and gallbladder to the liver. It is formed by the union of the superior mesenteric vein (draining the small intestine and a portion of the large intestine) and the splenic vein (draining the spleen and pancreas). The portal vein then divides into right and left branches within the liver, where the blood flows through the sinusoids and gets enriched with oxygen and nutrients before being drained by the hepatic veins into the inferior vena cava. This unique arrangement allows the liver to process and detoxify the absorbed nutrients, remove waste products, and regulate metabolic homeostasis.

Posture is the position or alignment of body parts supported by the muscles, especially the spine and head in relation to the vertebral column. It can be described as static (related to a stationary position) or dynamic (related to movement). Good posture involves training your body to stand, walk, sit, and lie in positions where the least strain is placed on supporting muscles and ligaments during movement or weight-bearing activities. Poor posture can lead to various health issues such as back pain, neck pain, headaches, and respiratory problems.

Intraoperative monitoring (IOM) is the practice of using specialized techniques to monitor physiological functions or neural structures in real-time during surgical procedures. The primary goal of IOM is to provide continuous information about the patient's status and the effects of surgery on neurological function, allowing surgeons to make informed decisions and minimize potential risks.

IOM can involve various methods such as:

1. Electrophysiological monitoring: This includes techniques like somatosensory evoked potentials (SSEP), motor evoked potentials (MEP), and electroencephalography (EEG) to assess the integrity of neural pathways and brain function during surgery.
2. Neuromonitoring: Direct electrical stimulation of nerves or spinal cord structures can help identify critical neuroanatomical structures, evaluate their functional status, and guide surgical interventions.
3. Hemodynamic monitoring: Measuring blood pressure, heart rate, cardiac output, and oxygen saturation helps assess the patient's overall physiological status during surgery.
4. Imaging modalities: Intraoperative imaging techniques like ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI) can provide real-time visualization of anatomical structures and surgical progress.

The specific IOM methods employed depend on the type of surgery, patient characteristics, and potential risks involved. Intraoperative monitoring is particularly crucial in procedures where there is a risk of neurological injury, such as spinal cord or brain surgeries, vascular interventions, or tumor resections near critical neural structures.

Hypovolemia is a medical condition characterized by a decreased volume of circulating blood in the body, leading to inadequate tissue perfusion and oxygenation. This can occur due to various reasons such as bleeding, dehydration, vomiting, diarrhea, or excessive sweating, which result in a reduced amount of fluid in the intravascular space.

The severity of hypovolemia depends on the extent of fluid loss and can range from mild to severe. Symptoms may include thirst, dry mouth, weakness, dizziness, lightheadedness, confusion, rapid heartbeat, low blood pressure, and decreased urine output. Severe hypovolemia can lead to shock, organ failure, and even death if not treated promptly and effectively.

Cerebrospinal Fluid Pressure (CSFP) is the pressure exerted by the cerebrospinal fluid (CSF), a clear, colorless fluid that surrounds and protects the brain and spinal cord. CSF acts as a cushion for the brain, allowing it to float within the skull and protecting it from trauma.

The normal range of CSFP is typically between 6 and 18 cm of water (cm H2O) when measured in the lateral decubitus position (lying on one's side). Elevated CSFP can be a sign of various medical conditions, such as hydrocephalus, meningitis, or brain tumors. Conversely, low CSFP may indicate dehydration or other underlying health issues.

It is important to monitor and maintain normal CSFP levels, as abnormal pressure can lead to serious neurological complications, including damage to the optic nerve, cognitive impairment, and even death in severe cases. Regular monitoring of CSFP may be necessary for individuals with conditions that affect CSF production or absorption.

Splanchnic circulation refers to the blood flow to the visceral organs, including the gastrointestinal tract, pancreas, spleen, and liver. These organs receive a significant portion of the cardiac output, with approximately 25-30% of the total restingly going to the splanchnic circulation. The splanchnic circulation is regulated by a complex interplay of neural and hormonal mechanisms that help maintain adequate blood flow to these vital organs while also allowing for the distribution of blood to other parts of the body as needed.

The splanchnic circulation is unique in its ability to vasodilate and increase blood flow significantly in response to meals or other stimuli, such as stress or hormonal changes. This increased blood flow helps support the digestive process and absorption of nutrients. At the same time, the body must carefully regulate this blood flow to prevent a significant drop in blood pressure or overloading the heart with too much work.

Overall, the splanchnic circulation plays a critical role in maintaining the health and function of the body's vital organs, and dysregulation of this system can contribute to various diseases, including digestive disorders, liver disease, and cardiovascular disease.

A tourniquet is a device or material used to apply pressure around an extremity, typically an arm or leg, with the goal of controlling severe bleeding (hemorrhage) by compressing blood vessels and limiting arterial flow. Tourniquets are usually applied as a last resort when direct pressure and elevation have failed to stop life-threatening bleeding. They should be used cautiously because they can cause tissue damage, nerve injury, or even amputation if left on for too long. In a medical setting, tourniquets are often applied by healthcare professionals in emergency situations; however, there are also specialized tourniquets available for use by trained individuals in the military, first responder communities, and civilians who have undergone proper training.

Liver cirrhosis is a chronic, progressive disease characterized by the replacement of normal liver tissue with scarred (fibrotic) tissue, leading to loss of function. The scarring is caused by long-term damage from various sources such as hepatitis, alcohol abuse, nonalcoholic fatty liver disease, and other causes. As the disease advances, it can lead to complications like portal hypertension, fluid accumulation in the abdomen (ascites), impaired brain function (hepatic encephalopathy), and increased risk of liver cancer. It is generally irreversible, but early detection and treatment of underlying causes may help slow down its progression.

The sympathetic nervous system (SNS) is a part of the autonomic nervous system that operates largely below the level of consciousness, and it functions to produce appropriate physiological responses to perceived danger. It's often associated with the "fight or flight" response. The SNS uses nerve impulses to stimulate target organs, causing them to speed up (e.g., increased heart rate), prepare for action, or otherwise respond to stressful situations.

The sympathetic nervous system is activated due to stressful emotional or physical situations and it prepares the body for immediate actions. It dilates the pupils, increases heart rate and blood pressure, accelerates breathing, and slows down digestion. The primary neurotransmitter involved in this system is norepinephrine (also known as noradrenaline).

Esophageal varices and gastric varices are abnormal, enlarged veins in the lower part of the esophagus (the tube that connects the throat to the stomach) and in the stomach lining, respectively. They occur as a result of increased pressure in the portal vein, which is the large blood vessel that carries blood from the digestive organs to the liver. This condition is known as portal hypertension.

Esophageal varices are more common than gastric varices and tend to be more symptomatic. They can cause bleeding, which can be life-threatening if not treated promptly. Gastric varices may also bleed, but they are often asymptomatic until they rupture.

The most common causes of esophageal and gastric varices are cirrhosis (scarring of the liver) and portal hypertension due to other liver diseases such as schistosomiasis or Budd-Chiari syndrome. Treatment options for esophageal and gastric varices include medications to reduce bleeding, endoscopic therapies to treat active bleeding or prevent recurrent bleeding, and surgical procedures to relieve portal hypertension.

Blood circulation, also known as cardiovascular circulation, refers to the process by which blood is pumped by the heart and circulated throughout the body through a network of blood vessels, including arteries, veins, and capillaries. This process ensures that oxygen and nutrients are delivered to cells and tissues, while waste products and carbon dioxide are removed.

The circulation of blood can be divided into two main parts: the pulmonary circulation and the systemic circulation. The pulmonary circulation involves the movement of blood between the heart and the lungs, where it picks up oxygen and releases carbon dioxide. The systemic circulation refers to the movement of blood between the heart and the rest of the body, delivering oxygen and nutrients to cells and tissues while picking up waste products for removal.

The heart plays a central role in blood circulation, acting as a pump that contracts and relaxes to move blood through the body. The contraction of the heart's left ventricle pushes oxygenated blood into the aorta, which then branches off into smaller arteries that carry blood throughout the body. The blood then flows through capillaries, where it exchanges oxygen and nutrients for waste products and carbon dioxide with surrounding cells and tissues. The deoxygenated blood is then collected in veins, which merge together to form larger vessels that eventually return the blood back to the heart's right atrium. From there, the blood is pumped into the lungs to pick up oxygen and release carbon dioxide, completing the cycle of blood circulation.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Ventricular pressure refers to the pressure within the ventricles, which are the lower chambers of the heart. In the left ventricle, the pressure measures the force that the blood exerts on the walls as it is pumped out to the rest of the body. In the right ventricle, the pressure measures the force of the blood being pumped into the pulmonary artery and ultimately to the lungs for oxygenation.

Normally, the left ventricular pressure ranges from 8-12 mmHg at rest when the heart is relaxed (diastolic pressure) and can increase up to 120-140 mmHg during contraction (systolic pressure). The right ventricular pressure is lower than the left, with a normal diastolic pressure of 0-6 mmHg and a systolic pressure ranging from 15-30 mmHg.

Abnormal ventricular pressures can indicate various heart conditions, such as heart failure, hypertension, or valvular heart disease. Regular monitoring of ventricular pressure is essential in managing these conditions and ensuring proper heart function.

Pressoreceptors are specialized sensory nerve endings found in the walls of blood vessels, particularly in the carotid sinus and aortic arch. They respond to changes in blood pressure by converting the mechanical stimulus into electrical signals that are transmitted to the brain. This information helps regulate cardiovascular function and maintain blood pressure homeostasis.

A portal system in medicine refers to a venous system in which veins from various tissues or organs (known as tributaries) drain into a common large vessel (known as the portal vein), which then carries the blood to a specific organ for filtration and processing before it is returned to the systemic circulation. The most well-known example of a portal system is the hepatic portal system, where veins from the gastrointestinal tract, spleen, pancreas, and stomach merge into the portal vein and then transport blood to the liver for detoxification and nutrient processing. Other examples include the hypophyseal portal system, which connects the hypothalamus to the anterior pituitary gland, and the renal portal system found in some animals.

In medical terms, the leg refers to the lower portion of the human body that extends from the knee down to the foot. It includes the thigh (femur), lower leg (tibia and fibula), foot, and ankle. The leg is primarily responsible for supporting the body's weight and enabling movements such as standing, walking, running, and jumping.

The leg contains several important structures, including bones, muscles, tendons, ligaments, blood vessels, nerves, and joints. These structures work together to provide stability, support, and mobility to the lower extremity. Common medical conditions that can affect the leg include fractures, sprains, strains, infections, peripheral artery disease, and neurological disorders.

Antihypertensive agents are a class of medications used to treat high blood pressure (hypertension). They work by reducing the force and rate of heart contractions, dilating blood vessels, or altering neurohormonal activation to lower blood pressure. Examples include diuretics, beta blockers, ACE inhibitors, ARBs, calcium channel blockers, and direct vasodilators. These medications may be used alone or in combination to achieve optimal blood pressure control.

Hypotension is a medical term that refers to abnormally low blood pressure, usually defined as a systolic blood pressure less than 90 millimeters of mercury (mm Hg) or a diastolic blood pressure less than 60 mm Hg. Blood pressure is the force exerted by the blood against the walls of the blood vessels as the heart pumps blood.

Hypotension can cause symptoms such as dizziness, lightheadedness, weakness, and fainting, especially when standing up suddenly. In severe cases, hypotension can lead to shock, which is a life-threatening condition characterized by multiple organ failure due to inadequate blood flow.

Hypotension can be caused by various factors, including certain medications, medical conditions such as heart disease, endocrine disorders, and dehydration. It is important to seek medical attention if you experience symptoms of hypotension, as it can indicate an underlying health issue that requires treatment.

The supine position is a term used in medicine to describe a body posture where an individual is lying down on their back, with their face and torso facing upwards. This position is often adopted during various medical procedures, examinations, or when resting, as it allows for easy access to the front of the body. It is also the position automatically assumed by most people who are falling asleep.

It's important to note that in the supine position, the head can be flat on the surface or raised with the use of pillows or specialized medical equipment like a hospital bed. This can help to alleviate potential issues such as breathing difficulties or swelling in the face and head.

Physiological monitoring is the continuous or intermittent observation and measurement of various body functions or parameters in a patient, with the aim of evaluating their health status, identifying any abnormalities or changes, and guiding clinical decision-making and treatment. This may involve the use of specialized medical equipment, such as cardiac monitors, pulse oximeters, blood pressure monitors, and capnographs, among others. The data collected through physiological monitoring can help healthcare professionals assess the effectiveness of treatments, detect complications early, and make timely adjustments to patient care plans.

Hydroxyethyl starch derivatives are modified starches that are used as plasma expanders in medicine. They are created by chemically treating corn, potato, or wheat starch with hydroxylethyl groups, which makes the starch more soluble and less likely to be broken down by enzymes in the body. This results in a large molecule that can remain in the bloodstream for an extended period, increasing intravascular volume and improving circulation.

These derivatives are available in different molecular weights and substitution patterns, which affect their pharmacokinetics and pharmacodynamics. They are used to treat or prevent hypovolemia (low blood volume) due to various causes such as bleeding, burns, or dehydration. Common brand names include Hetastarch, Pentastarch, and Voluven.

It's important to note that the use of hydroxyethyl starch derivatives has been associated with adverse effects, including kidney injury, coagulopathy, and pruritus (severe itching). Therefore, their use should be carefully monitored and restricted to specific clinical situations.

Head-down tilt (HDT) is a positioning technique often used in medical settings, particularly during diagnostic procedures or treatment interventions. In this position, the person lies down on a specially designed table with their head tilted below the horizontal plane, typically at an angle of 6 degrees to 15 degrees, but sometimes as steep as 90 degrees. This posture allows for various medical evaluations such as carotid sinus massage or intracranial pressure monitoring. It is also used in space medicine to simulate some effects of weightlessness on the human body during spaceflight. Please note that prolonged exposure to head-down tilt can have physiological consequences, including changes in blood pressure, heart rate, and eye function, which should be monitored and managed by healthcare professionals.

Osmotic pressure is a fundamental concept in the field of physiology and biochemistry. It refers to the pressure that is required to be applied to a solution to prevent the flow of solvent (like water) into it, through a semi-permeable membrane, when the solution is separated from a pure solvent or a solution of lower solute concentration.

In simpler terms, osmotic pressure is the force that drives the natural movement of solvent molecules from an area of lower solute concentration to an area of higher solute concentration, across a semi-permeable membrane. This process is crucial for maintaining the fluid balance and nutrient transport in living organisms.

The osmotic pressure of a solution can be determined by its solute concentration, temperature, and the ideal gas law. It is often expressed in units of atmospheres (atm), millimeters of mercury (mmHg), or pascals (Pa). In medical contexts, understanding osmotic pressure is essential for managing various clinical conditions such as dehydration, fluid and electrolyte imbalances, and dialysis treatments.

Blood flow velocity is the speed at which blood travels through a specific part of the vascular system. It is typically measured in units of distance per time, such as centimeters per second (cm/s) or meters per second (m/s). Blood flow velocity can be affected by various factors, including cardiac output, vessel diameter, and viscosity of the blood. Measuring blood flow velocity is important in diagnosing and monitoring various medical conditions, such as heart disease, stroke, and peripheral vascular disease.

Anesthesia is a medical term that refers to the loss of sensation or awareness, usually induced by the administration of various drugs. It is commonly used during surgical procedures to prevent pain and discomfort. There are several types of anesthesia, including:

1. General anesthesia: This type of anesthesia causes a complete loss of consciousness and is typically used for major surgeries.
2. Regional anesthesia: This type of anesthesia numbs a specific area of the body, such as an arm or leg, while the patient remains conscious.
3. Local anesthesia: This type of anesthesia numbs a small area of the body, such as a cut or wound, and is typically used for minor procedures.

Anesthesia can be administered through various routes, including injection, inhalation, or topical application. The choice of anesthesia depends on several factors, including the type and duration of the procedure, the patient's medical history, and their overall health. Anesthesiologists are medical professionals who specialize in administering anesthesia and monitoring patients during surgical procedures to ensure their safety and comfort.

The femoral vein is the large vein that runs through the thigh and carries oxygen-depleted blood from the lower limbs back to the heart. It is located in the femoral triangle, along with the femoral artery and nerve. The femoral vein begins at the knee as the popliteal vein, which then joins with the deep vein of the thigh to form the femoral vein. As it moves up the leg, it is joined by several other veins, including the great saphenous vein, before it becomes the external iliac vein at the inguinal ligament in the groin.

In medical terms, compliance refers to the degree to which a patient follows the recommendations or instructions of their healthcare provider. This may include taking prescribed medications as directed, following a treatment plan, making lifestyle changes, or attending follow-up appointments. Good compliance is essential for achieving the best possible health outcomes and can help prevent complications or worsening of medical conditions. Factors that can affect patient compliance include forgetfulness, lack of understanding of the instructions, cost of medications or treatments, and side effects of medications. Healthcare providers can take steps to improve patient compliance by providing clear and concise instructions, discussing potential barriers to compliance, and involving patients in their care plan.

Positive-pressure respiration is a type of mechanical ventilation where positive pressure is applied to the airway and lungs, causing them to expand and inflate. This can be used to support or replace spontaneous breathing in patients who are unable to breathe effectively on their own due to conditions such as respiratory failure, neuromuscular disorders, or sedation for surgery.

During positive-pressure ventilation, a mechanical ventilator delivers breaths to the patient through an endotracheal tube or a tracheostomy tube. The ventilator is set to deliver a specific volume or pressure of air with each breath, and the patient's breathing is synchronized with the ventilator to ensure proper delivery of the breaths.

Positive-pressure ventilation can help improve oxygenation and remove carbon dioxide from the lungs, but it can also have potential complications such as barotrauma (injury to lung tissue due to excessive pressure), volutrauma (injury due to overdistention of the lungs), hemodynamic compromise (decreased blood pressure and cardiac output), and ventilator-associated pneumonia. Therefore, careful monitoring and adjustment of ventilator settings are essential to minimize these risks and provide safe and effective respiratory support.

Varicose veins are defined as enlarged, swollen, and twisting veins often appearing blue or dark purple, which usually occur in the legs. They are caused by weakened valves and vein walls that can't effectively push blood back toward the heart. This results in a buildup of blood, causing the veins to bulge and become varicose.

The condition is generally harmless but may cause symptoms like aching, burning, muscle cramp, or a feeling of heaviness in the legs. In some cases, varicose veins can lead to more serious problems, such as skin ulcers, blood clots, or chronic venous insufficiency. Treatment options include lifestyle changes, compression stockings, and medical procedures like sclerotherapy, laser surgery, or endovenous ablation.

Isotonic solutions are defined in the context of medical and physiological sciences as solutions that contain the same concentration of solutes (dissolved particles) as another solution, usually the bodily fluids like blood. This means that if you compare the concentration of solute particles in two isotonic solutions, they will be equal.

A common example is a 0.9% sodium chloride (NaCl) solution, also known as normal saline. The concentration of NaCl in this solution is approximately equal to the concentration found in the fluid portion of human blood, making it isotonic with blood.

Isotonic solutions are crucial in medical settings for various purposes, such as intravenous (IV) fluids replacement, wound care, and irrigation solutions. They help maintain fluid balance, prevent excessive water movement across cell membranes, and reduce the risk of damaging cells due to osmotic pressure differences between the solution and bodily fluids.

A reflex is an automatic, involuntary and rapid response to a stimulus that occurs without conscious intention. In the context of physiology and neurology, it's a basic mechanism that involves the transmission of nerve impulses between neurons, resulting in a muscle contraction or glandular secretion.

Reflexes are important for maintaining homeostasis, protecting the body from harm, and coordinating movements. They can be tested clinically to assess the integrity of the nervous system, such as the knee-j jerk reflex, which tests the function of the L3-L4 spinal nerve roots and the sensitivity of the stretch reflex arc.

The sclera is the tough, white, fibrous outer coating of the eye in humans and other vertebrates, covering about five sixths of the eyeball's surface. It provides protection for the delicate inner structures of the eye and maintains its shape. The sclera is composed mainly of collagen and elastic fiber, making it strong and resilient. Its name comes from the Greek word "skleros," which means hard.

General anesthesia is a state of controlled unconsciousness, induced by administering various medications, that eliminates awareness, movement, and pain sensation during medical procedures. It involves the use of a combination of intravenous and inhaled drugs to produce a reversible loss of consciousness, allowing patients to undergo surgical or diagnostic interventions safely and comfortably. The depth and duration of anesthesia are carefully monitored and adjusted throughout the procedure by an anesthesiologist or certified registered nurse anesthetist (CRNA) to ensure patient safety and optimize recovery. General anesthesia is typically used for more extensive surgical procedures, such as open-heart surgery, major orthopedic surgeries, and neurosurgery.

The baroreflex is a physiological mechanism that helps regulate blood pressure and heart rate in response to changes in stretch of the arterial walls. It is mediated by baroreceptors, which are specialized sensory nerve endings located in the carotid sinus and aortic arch. These receptors detect changes in blood pressure and send signals to the brainstem via the glossopharyngeal (cranial nerve IX) and vagus nerves (cranial nerve X), respectively.

In response to an increase in arterial pressure, the baroreceptors are stimulated, leading to increased firing of afferent neurons that signal the brainstem. This results in a reflexive decrease in heart rate and cardiac output, as well as vasodilation of peripheral blood vessels, which collectively work to reduce blood pressure back towards its normal level. Conversely, if arterial pressure decreases, the baroreceptors are less stimulated, leading to an increase in heart rate and cardiac output, as well as vasoconstriction of peripheral blood vessels, which helps restore blood pressure.

Overall, the baroreflex is a crucial homeostatic mechanism that helps maintain stable blood pressure and ensure adequate perfusion of vital organs.

Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.

Diastole is the phase of the cardiac cycle during which the heart muscle relaxes and the chambers of the heart fill with blood. It follows systole, the phase in which the heart muscle contracts and pumps blood out to the body. In a normal resting adult, diastole lasts for approximately 0.4-0.5 seconds during each heartbeat. The period of diastole is divided into two phases: early diastole and late diastole. During early diastole, the ventricles fill with blood due to the pressure difference between the atria and ventricles. During late diastole, the atrioventricular valves close, and the ventricles continue to fill with blood due to the relaxation of the ventricular muscle and the compliance of the ventricular walls. The duration and pressure changes during diastole are important for maintaining adequate cardiac output and blood flow to the body.

In medical terms, the heart is a muscular organ located in the thoracic cavity that functions as a pump to circulate blood throughout the body. It's responsible for delivering oxygen and nutrients to the tissues and removing carbon dioxide and other wastes. The human heart is divided into four chambers: two atria on the top and two ventricles on the bottom. The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs, while the left side receives oxygenated blood from the lungs and pumps it out to the rest of the body. The heart's rhythmic contractions and relaxations are regulated by a complex electrical conduction system.

In medical terms, constriction refers to the narrowing or tightening of a body part or passageway. This can occur due to various reasons such as spasms of muscles, inflammation, or abnormal growths. It can lead to symptoms like difficulty in breathing, swallowing, or blood flow, depending on where it occurs. For example, constriction of the airways in asthma, constriction of blood vessels in hypertension, or constriction of the esophagus in certain digestive disorders.

The superior vena cava is a large vein that carries deoxygenated blood from the upper half of the body to the right atrium of the heart. It is formed by the union of the left and right brachiocephalic veins (also known as the internal jugular and subclavian veins) near the base of the neck. The superior vena cava runs posteriorly to the sternum and enters the upper right portion of the right atrium, just posterior to the opening of the inferior vena cava. It plays a crucial role in the circulatory system by allowing blood returning from the head, neck, upper limbs, and thorax to bypass the liver before entering the heart.

Oxygen is a colorless, odorless, tasteless gas that constitutes about 21% of the earth's atmosphere. It is a crucial element for human and most living organisms as it is vital for respiration. Inhaled oxygen enters the lungs and binds to hemoglobin in red blood cells, which carries it to tissues throughout the body where it is used to convert nutrients into energy and carbon dioxide, a waste product that is exhaled.

Medically, supplemental oxygen therapy may be provided to patients with conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, or other medical conditions that impair the body's ability to extract sufficient oxygen from the air. Oxygen can be administered through various devices, including nasal cannulas, face masks, and ventilators.

A varicose ulcer is a type of chronic wound that typically occurs on the lower leg, often as a result of poor circulation and venous insufficiency. These ulcers form when there is increased pressure in the veins, leading to damage and leakage of fluids into the surrounding tissues. Over time, this can cause the skin to break down and form an open sore or ulcer.

Varicose ulcers are often associated with varicose veins, which are swollen and twisted veins that are visible just beneath the surface of the skin. These veins have weakened walls and valves, which can lead to the pooling of blood and fluid in the lower legs. This increased pressure can cause damage to the surrounding tissues, leading to the formation of an ulcer.

Varicose ulcers are typically slow to heal and may require extensive treatment, including compression therapy, wound care, and sometimes surgery. Risk factors for developing varicose ulcers include obesity, smoking, sedentary lifestyle, and a history of deep vein thrombosis or other circulatory problems.

Medical Definition of Respiration:

Respiration, in physiology, is the process by which an organism takes in oxygen and gives out carbon dioxide. It's also known as breathing. This process is essential for most forms of life because it provides the necessary oxygen for cellular respiration, where the cells convert biochemical energy from nutrients into adenosine triphosphate (ATP), and releases waste products, primarily carbon dioxide.

In humans and other mammals, respiration is a two-stage process:

1. Breathing (or external respiration): This involves the exchange of gases with the environment. Air enters the lungs through the mouth or nose, then passes through the pharynx, larynx, trachea, and bronchi, finally reaching the alveoli where the actual gas exchange occurs. Oxygen from the inhaled air diffuses into the blood, while carbon dioxide, a waste product of metabolism, diffuses from the blood into the alveoli to be exhaled.

2. Cellular respiration (or internal respiration): This is the process by which cells convert glucose and other nutrients into ATP, water, and carbon dioxide in the presence of oxygen. The carbon dioxide produced during this process then diffuses out of the cells and into the bloodstream to be exhaled during breathing.

In summary, respiration is a vital physiological function that enables organisms to obtain the necessary oxygen for cellular metabolism while eliminating waste products like carbon dioxide.

The popliteal vein is the continuation of the tibial and fibular (or anterior and posterior tibial) veins, forming in the lower leg's back portion or popliteal fossa. It carries blood from the leg towards the heart. The popliteal vein is located deep within the body and is accompanied by the popliteal artery, which supplies oxygenated blood to the lower leg. This venous structure is a crucial part of the venous system in the lower extremities and is often assessed during physical examinations for signs of venous insufficiency or deep vein thrombosis (DVT).

An air embolism is a medical condition that occurs when one or more air bubbles enter the bloodstream and block or obstruct blood vessels. This can lead to various symptoms depending on the severity and location of the obstruction, including shortness of breath, chest pain, confusion, stroke, or even death.

Air embolisms can occur in a variety of ways, such as during certain medical procedures (e.g., when air is accidentally introduced into a vein or artery), trauma to the lungs or blood vessels, scuba diving, or mountain climbing. Treatment typically involves administering oxygen and supportive care, as well as removing the source of the air bubbles if possible. In severe cases, hyperbaric oxygen therapy may be used to help reduce the size of the air bubbles and improve outcomes.

Cardiovascular models are simplified representations or simulations of the human cardiovascular system used in medical research, education, and training. These models can be physical, computational, or mathematical and are designed to replicate various aspects of the heart, blood vessels, and blood flow. They can help researchers study the structure and function of the cardiovascular system, test new treatments and interventions, and train healthcare professionals in diagnostic and therapeutic techniques.

Physical cardiovascular models may include artificial hearts, blood vessels, or circulation systems made from materials such as plastic, rubber, or silicone. These models can be used to study the mechanics of heart valves, the effects of different surgical procedures, or the impact of various medical devices on blood flow.

Computational and mathematical cardiovascular models use algorithms and equations to simulate the behavior of the cardiovascular system. These models may range from simple representations of a single heart chamber to complex simulations of the entire circulatory system. They can be used to study the electrical activity of the heart, the biomechanics of blood flow, or the distribution of drugs in the body.

Overall, cardiovascular models play an essential role in advancing our understanding of the human body and improving patient care.

The inferior vena cava (IVC) is the largest vein in the human body that carries deoxygenated blood from the lower extremities, pelvis, and abdomen to the right atrium of the heart. It is formed by the union of the left and right common iliac veins at the level of the fifth lumbar vertebra. The inferior vena cava is a retroperitoneal structure, meaning it lies behind the peritoneum, the lining that covers the abdominal cavity. It ascends through the posterior abdominal wall and passes through the central tendon of the diaphragm to enter the thoracic cavity.

The inferior vena cava is composed of three parts:

1. The infrarenal portion, which lies below the renal veins
2. The renal portion, which receives blood from the renal veins
3. The suprahepatic portion, which lies above the liver and receives blood from the hepatic veins before draining into the right atrium of the heart.

The inferior vena cava plays a crucial role in maintaining venous return to the heart and contributing to cardiovascular function.

The forearm is the region of the upper limb between the elbow and the wrist. It consists of two bones, the radius and ulna, which are located side by side and run parallel to each other. The forearm is responsible for movements such as flexion, extension, supination, and pronation of the hand and wrist.

The renal veins are a pair of large veins that carry oxygen-depleted blood and waste products from the kidneys to the inferior vena cava, which is the largest vein in the body that returns blood to the heart. The renal veins are formed by the union of several smaller veins that drain blood from different parts of the kidney.

In humans, the right renal vein is shorter and passes directly into the inferior vena cava, while the left renal vein is longer and passes in front of the aorta before entering the inferior vena cava. The left renal vein also receives blood from the gonadal (testicular or ovarian) veins, suprarenal (adrenal) veins, and the lumbar veins.

It is important to note that the renal veins are vulnerable to compression by surrounding structures, such as the overlying artery or a tumor, which can lead to renal vein thrombosis, a serious condition that requires prompt medical attention.

The Fontan procedure is a type of open-heart surgery used to treat specific types of complex congenital (present at birth) heart defects. It's typically performed on children with single ventricle hearts, where one of the heart's lower chambers (the right or left ventricle) is underdeveloped or missing.

In a normal heart, oxygen-poor (blue) blood returns from the body to the right atrium, then flows through the tricuspid valve into the right ventricle. The right ventricle pumps the blue blood to the lungs, where it picks up oxygen and turns red. Oxygen-rich (red) blood then returns from the lungs to the left atrium, flows through the mitral valve into the left ventricle, and the left ventricle pumps it out to the body through the aorta.

However, in a single ventricle heart, the underdeveloped or missing ventricle cannot effectively pump blood to the lungs and the body simultaneously. The Fontan procedure aims to separate the blue and red blood circulation to improve oxygenation of the body's tissues.

The Fontan procedure involves two stages:

1. In the first stage, usually performed in infancy, a shunt or a band is placed around the pulmonary artery (the blood vessel that carries blood from the heart to the lungs) to control the amount of blood flowing into the lungs. This helps prevent lung congestion due to excessive blood flow.
2. The second stage, the Fontan procedure itself, takes place when the child is between 18 months and 4 years old. During this surgery, the surgeon creates a connection between the inferior vena cava (the large vein that returns blue blood from the lower body to the heart) and the pulmonary artery. This allows oxygen-poor blood to flow directly into the lungs without passing through the underdeveloped ventricle.

The Fontan procedure significantly improves the quality of life for many children with single ventricle hearts, although they may still face long-term complications such as heart failure, arrhythmias, and protein-losing enteropathy (a condition where the body loses too much protein in the stool). Regular follow-up care with a pediatric cardiologist is essential to monitor their health and manage any potential issues.

Pulmonary circulation refers to the process of blood flow through the lungs, where blood picks up oxygen and releases carbon dioxide. This is a vital part of the overall circulatory system, which delivers nutrients and oxygen to the body's cells while removing waste products like carbon dioxide.

In pulmonary circulation, deoxygenated blood from the systemic circulation returns to the right atrium of the heart via the superior and inferior vena cava. The blood then moves into the right ventricle through the tricuspid valve and gets pumped into the pulmonary artery when the right ventricle contracts.

The pulmonary artery divides into smaller vessels called arterioles, which further branch into a vast network of tiny capillaries in the lungs. Here, oxygen from the alveoli diffuses into the blood, binding to hemoglobin in red blood cells, while carbon dioxide leaves the blood and is exhaled through the nose or mouth.

The now oxygenated blood collects in venules, which merge to form pulmonary veins. These veins transport the oxygen-rich blood back to the left atrium of the heart, where it enters the systemic circulation once again. This continuous cycle enables the body's cells to receive the necessary oxygen and nutrients for proper functioning while disposing of waste products.

Propoxycaine is a local anesthetic that was previously used in medical and dental procedures for its numbing effect. It works by blocking the nerve impulses in the area where it is administered, thus reducing the sensation of pain. However, its use has become less common due to the development of safer and more effective alternatives.

The chemical name for Propoxycaine is 2-diethylamino-N-(1-methoxyprop-2-yl)butanamide. It is a derivative of procaine, another local anesthetic, with an added methoxy group to the propanolamine side chain. This modification was intended to increase its potency and duration of action compared to procaine.

Propoxycaine can be administered through various routes, including topical application, injection, or as a suppository. Its effects typically begin within a few minutes after administration and last for up to an hour. Common side effects may include localized pain, redness, or swelling at the site of injection, as well as more systemic effects such as dizziness, headache, or heart palpitations.

It is important to note that Propoxycaine is no longer widely used in clinical practice due to its association with rare but serious side effects, including allergic reactions, seizures, and cardiac arrhythmias. Therefore, its use is generally restricted to specific indications and under the close supervision of a healthcare professional.

In medical terms, the foot is the part of the lower limb that is distal to the leg and below the ankle, extending from the tarsus to the toes. It is primarily responsible for supporting body weight and facilitating movement through push-off during walking or running. The foot is a complex structure made up of 26 bones, 33 joints, and numerous muscles, tendons, ligaments, and nerves that work together to provide stability, balance, and flexibility. It can be divided into three main parts: the hindfoot, which contains the talus and calcaneus (heel) bones; the midfoot, which includes the navicular, cuboid, and cuneiform bones; and the forefoot, which consists of the metatarsals and phalanges that form the toes.

Central venous catheterization is a medical procedure in which a flexible tube called a catheter is inserted into a large vein in the body, usually in the neck (internal jugular vein), chest (subclavian vein), or groin (femoral vein). The catheter is threaded through the vein until it reaches a central location, such as the superior vena cava or the right atrium of the heart.

Central venous catheterization may be performed for several reasons, including:

1. To administer medications, fluids, or nutritional support directly into the bloodstream.
2. To monitor central venous pressure (CVP), which can help assess a patient's volume status and cardiac function.
3. To draw blood samples for laboratory tests.
4. To deliver chemotherapy drugs or other medications that may be harmful to peripheral veins.
5. To provide access for hemodialysis or other long-term therapies.

The procedure requires careful attention to sterile technique to minimize the risk of infection, and it is usually performed under local anesthesia with sedation or general anesthesia. Complications of central venous catheterization may include bleeding, infection, pneumothorax (collapsed lung), arterial puncture, and catheter-related bloodstream infections (CRBSI).

The pulmonary artery is a large blood vessel that carries deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation. It divides into two main branches, the right and left pulmonary arteries, which further divide into smaller vessels called arterioles, and then into a vast network of capillaries in the lungs where gas exchange occurs. The thin walls of these capillaries allow oxygen to diffuse into the blood and carbon dioxide to diffuse out, making the blood oxygen-rich before it is pumped back to the left side of the heart through the pulmonary veins. This process is crucial for maintaining proper oxygenation of the body's tissues and organs.

Pulmonary edema is a medical condition characterized by the accumulation of fluid in the alveoli (air sacs) and interstitial spaces (the area surrounding the alveoli) within the lungs. This buildup of fluid can lead to impaired gas exchange, resulting in shortness of breath, coughing, and difficulty breathing, especially when lying down. Pulmonary edema is often a complication of heart failure, but it can also be caused by other conditions such as pneumonia, trauma, or exposure to certain toxins.

In the early stages of pulmonary edema, patients may experience mild symptoms such as shortness of breath during physical activity. However, as the condition progresses, symptoms can become more severe and include:

* Severe shortness of breath, even at rest
* Wheezing or coughing up pink, frothy sputum
* Rapid breathing and heart rate
* Anxiety or restlessness
* Bluish discoloration of the skin (cyanosis) due to lack of oxygen

Pulmonary edema can be diagnosed through a combination of physical examination, medical history, chest X-ray, and other diagnostic tests such as echocardiography or CT scan. Treatment typically involves addressing the underlying cause of the condition, as well as providing supportive care such as supplemental oxygen, diuretics to help remove excess fluid from the body, and medications to help reduce anxiety and improve breathing. In severe cases, mechanical ventilation may be necessary to support respiratory function.

Right atrial function refers to the role and performance of the right atrium in the heart. The right atrium is one of the four chambers of the heart and is responsible for receiving deoxygenated blood from the body via the superior and inferior vena cava. It then contracts to help pump the blood into the right ventricle, which subsequently sends it to the lungs for oxygenation.

Right atrial function can be assessed through various methods, including echocardiography, cardiac magnetic resonance imaging (MRI), and electrocardiogram (ECG). Abnormalities in right atrial function may indicate underlying heart conditions such as right-sided heart failure, atrial fibrillation, or other cardiovascular diseases. Proper evaluation and monitoring of right atrial function are essential for effective diagnosis, treatment, and management of these conditions.

Arteries are blood vessels that carry oxygenated blood away from the heart to the rest of the body. They have thick, muscular walls that can withstand the high pressure of blood being pumped out of the heart. Arteries branch off into smaller vessels called arterioles, which further divide into a vast network of tiny capillaries where the exchange of oxygen, nutrients, and waste occurs between the blood and the body's cells. After passing through the capillary network, deoxygenated blood collects in venules, then merges into veins, which return the blood back to the heart.

The cardiovascular system, also known as the circulatory system, is a biological system responsible for pumping and transporting blood throughout the body in animals and humans. It consists of the heart, blood vessels (comprising arteries, veins, and capillaries), and blood. The main function of this system is to transport oxygen, nutrients, hormones, and cellular waste products throughout the body to maintain homeostasis and support organ function.

The heart acts as a muscular pump that contracts and relaxes to circulate blood. It has four chambers: two atria on the top and two ventricles on the bottom. The right side of the heart receives deoxygenated blood from the body, pumps it through the lungs for oxygenation, and then sends it back to the left side of the heart. The left side of the heart then pumps the oxygenated blood through the aorta and into the systemic circulation, reaching all parts of the body via a network of arteries and capillaries. Deoxygenated blood is collected by veins and returned to the right atrium, completing the cycle.

The cardiovascular system plays a crucial role in regulating temperature, pH balance, and fluid balance throughout the body. It also contributes to the immune response and wound healing processes. Dysfunctions or diseases of the cardiovascular system can lead to severe health complications, such as hypertension, coronary artery disease, heart failure, stroke, and peripheral artery disease.

Systole is the phase of the cardiac cycle during which the heart muscle contracts to pump blood out of the heart. Specifically, it refers to the contraction of the ventricles, the lower chambers of the heart. This is driven by the action of the electrical conduction system of the heart, starting with the sinoatrial node and passing through the atrioventricular node and bundle branches to the Purkinje fibers.

During systole, the pressure within the ventricles increases as they contract, causing the aortic and pulmonary valves to open and allowing blood to be ejected into the systemic and pulmonary circulations, respectively. The duration of systole is typically shorter than that of diastole, the phase during which the heart muscle relaxes and the chambers fill with blood.

In clinical settings, the terms "systolic" and "diastolic" are often used to describe blood pressure measurements, with the former referring to the pressure exerted on the artery walls when the ventricles contract and eject blood, and the latter referring to the pressure when the ventricles are relaxed and filling with blood.

Colloids are a type of mixture that contains particles that are intermediate in size between those found in solutions and suspensions. These particles range in size from about 1 to 1000 nanometers in diameter, which is smaller than what can be seen with the naked eye, but larger than the molecules in a solution.

Colloids are created when one substance, called the dispersed phase, is dispersed in another substance, called the continuous phase. The dispersed phase can consist of particles such as proteins, emulsified fats, or finely divided solids, while the continuous phase is usually a liquid, but can also be a gas or a solid.

Colloids are important in many areas of medicine and biology, including drug delivery, diagnostic imaging, and tissue engineering. They are also found in nature, such as in milk, blood, and fog. The properties of colloids can be affected by factors such as pH, temperature, and the presence of other substances, which can influence their stability and behavior.

A "Heart Bypass, Right" or Right Coronary Artery Bypass Graft (RCA Bypass) is a surgical procedure that aims to improve the blood supply to the right side of the heart. It involves grafting a healthy blood vessel, usually taken from another part of the body, to divert blood flow around a blocked or narrowed section of the right coronary artery (RCA). The RCA supplies blood to the right ventricle and the back of the left ventricle. By creating this bypass, the surgery helps restore adequate oxygenated blood flow to the heart muscle, reducing the risk of damage or failure due to insufficient blood supply, and alleviating symptoms such as angina and shortness of breath.

It is important to note that "Heart Bypass, Right" specifically refers to bypass surgery on the right coronary artery, while a standard "Heart Bypass Surgery," also known as Coronary Artery Bypass Grafting (CABG), typically involves bypassing blockages in multiple coronary arteries.

Carbon dioxide (CO2) is a colorless, odorless gas that is naturally present in the Earth's atmosphere. It is a normal byproduct of cellular respiration in humans, animals, and plants, and is also produced through the combustion of fossil fuels such as coal, oil, and natural gas.

In medical terms, carbon dioxide is often used as a respiratory stimulant and to maintain the pH balance of blood. It is also used during certain medical procedures, such as laparoscopic surgery, to insufflate (inflate) the abdominal cavity and create a working space for the surgeon.

Elevated levels of carbon dioxide in the body can lead to respiratory acidosis, a condition characterized by an increased concentration of carbon dioxide in the blood and a decrease in pH. This can occur in conditions such as chronic obstructive pulmonary disease (COPD), asthma, or other lung diseases that impair breathing and gas exchange. Symptoms of respiratory acidosis may include shortness of breath, confusion, headache, and in severe cases, coma or death.

Peripheral catheterization is a medical procedure that involves the insertion of a thin, flexible tube (catheter) into a peripheral vein, which is a blood vessel located outside of the chest and abdomen. This type of catheterization is typically performed to administer medications, fluids, or nutritional support, or to monitor various physiological parameters such as central venous pressure.

Peripheral catheters are usually inserted into veins in the hands or arms, although they can also be placed in other peripheral veins. The procedure is typically performed using aseptic technique to minimize the risk of infection. Once the catheter is in place, it may be secured with a dressing or suture to prevent movement and dislodgement.

Peripheral catheterization is a relatively safe and common procedure that is routinely performed in hospitals, clinics, and other healthcare settings. However, like any medical procedure, it carries a small risk of complications such as infection, bleeding, or damage to the vein or surrounding tissues.

Blood volume determination is a medical procedure that involves measuring the total amount of blood present in an individual's circulatory system. This measurement is typically expressed in milliliters (mL) or liters (L) and provides important information about the person's overall cardiovascular health and fluid status.

There are several methods for determining blood volume, including:

1. Direct measurement: This involves withdrawing a known volume of blood from the body, labeling the red blood cells with a radioactive or dye marker, reinfusing the cells back into the body, and then measuring the amount of marked cells that appear in subsequent blood samples over time.
2. Indirect measurement: This method uses formulas based on the person's height, weight, sex, and other factors to estimate their blood volume. One common indirect method is the "hemodynamic" calculation, which takes into account the individual's heart rate, stroke volume (the amount of blood pumped by the heart with each beat), and the concentration of hemoglobin in their red blood cells.
3. Bioimpedance analysis: This non-invasive technique uses electrical signals to measure the body's fluid volumes, including blood volume. By analyzing changes in the body's electrical conductivity in response to a small current, bioimpedance analysis can provide an estimate of blood volume.

Accurate determination of blood volume is important for assessing various medical conditions, such as heart failure, shock, anemia, and dehydration. It can also help guide treatment decisions, including the need for fluid replacement or blood transfusions.

Treatment outcome is a term used to describe the result or effect of medical treatment on a patient's health status. It can be measured in various ways, such as through symptoms improvement, disease remission, reduced disability, improved quality of life, or survival rates. The treatment outcome helps healthcare providers evaluate the effectiveness of a particular treatment plan and make informed decisions about future care. It is also used in clinical research to compare the efficacy of different treatments and improve patient care.

Perfusion, in medical terms, refers to the process of circulating blood through the body's organs and tissues to deliver oxygen and nutrients and remove waste products. It is a measure of the delivery of adequate blood flow to specific areas or tissues in the body. Perfusion can be assessed using various methods, including imaging techniques like computed tomography (CT) scans, magnetic resonance imaging (MRI), and perfusion scintigraphy.

Perfusion is critical for maintaining proper organ function and overall health. When perfusion is impaired or inadequate, it can lead to tissue hypoxia, acidosis, and cell death, which can result in organ dysfunction or failure. Conditions that can affect perfusion include cardiovascular disease, shock, trauma, and certain surgical procedures.

Norepinephrine, also known as noradrenaline, is a neurotransmitter and a hormone that is primarily produced in the adrenal glands and is released into the bloodstream in response to stress or physical activity. It plays a crucial role in the "fight-or-flight" response by preparing the body for action through increasing heart rate, blood pressure, respiratory rate, and glucose availability.

As a neurotransmitter, norepinephrine is involved in regulating various functions of the nervous system, including attention, perception, motivation, and arousal. It also plays a role in modulating pain perception and responding to stressful or emotional situations.

In medical settings, norepinephrine is used as a vasopressor medication to treat hypotension (low blood pressure) that can occur during septic shock, anesthesia, or other critical illnesses. It works by constricting blood vessels and increasing heart rate, which helps to improve blood pressure and perfusion of vital organs.

In medical terms, shock is a life-threatening condition that occurs when the body is not getting enough blood flow or when the circulatory system is not functioning properly to distribute oxygen and nutrients to the tissues and organs. This results in a state of hypoxia (lack of oxygen) and cellular dysfunction, which can lead to multiple organ failure and death if left untreated.

Shock can be caused by various factors such as severe blood loss, infection, trauma, heart failure, allergic reactions, and severe burns. The symptoms of shock include low blood pressure, rapid pulse, cool and clammy skin, rapid and shallow breathing, confusion, weakness, and a bluish color to the lips and nails. Immediate medical attention is required for proper diagnosis and treatment of shock.

The azygos vein is a large, unpaired venous structure in the thoracic cavity of the human body. It begins as the ascending lumbar vein, which receives blood from the lower extremities and abdominal organs. As it enters the thorax through the diaphragm, it becomes the azygos vein and continues to ascend along the vertebral column.

The azygos vein receives blood from various tributaries, including the intercostal veins, esophageal veins, mediastinal veins, and bronchial veins. It then arches over the right mainstem bronchus and empties into the superior vena cava, which returns blood to the right atrium of the heart.

The azygos vein provides an important collateral pathway for venous return in cases where the inferior vena cava is obstructed or occluded. It also plays a role in the spread of certain thoracic diseases, such as tuberculosis and cancer.

Gastrointestinal (GI) hemorrhage is a term used to describe any bleeding that occurs in the gastrointestinal tract, which includes the esophagus, stomach, small intestine, large intestine, and rectum. The bleeding can range from mild to severe and can produce symptoms such as vomiting blood, passing black or tarry stools, or having low blood pressure.

GI hemorrhage can be classified as either upper or lower, depending on the location of the bleed. Upper GI hemorrhage refers to bleeding that occurs above the ligament of Treitz, which is a point in the small intestine where it becomes narrower and turns a corner. Common causes of upper GI hemorrhage include gastritis, ulcers, esophageal varices, and Mallory-Weiss tears.

Lower GI hemorrhage refers to bleeding that occurs below the ligament of Treitz. Common causes of lower GI hemorrhage include diverticulosis, colitis, inflammatory bowel disease, and vascular abnormalities such as angiodysplasia.

The diagnosis of GI hemorrhage is often made based on the patient's symptoms, medical history, physical examination, and diagnostic tests such as endoscopy, CT scan, or radionuclide scanning. Treatment depends on the severity and cause of the bleeding and may include medications, endoscopic procedures, surgery, or a combination of these approaches.

Intraoperative care refers to the medical care and interventions provided to a patient during a surgical procedure. This care is typically administered by a team of healthcare professionals, including anesthesiologists, surgeons, nurses, and other specialists as needed. The goal of intraoperative care is to maintain the patient's physiological stability throughout the surgery, minimize complications, and ensure the best possible outcome.

Intraoperative care may include:

1. Anesthesia management: Administering and monitoring anesthetic drugs to keep the patient unconscious and free from pain during the surgery.
2. Monitoring vital signs: Continuously tracking the patient's heart rate, blood pressure, oxygen saturation, body temperature, and other key physiological parameters to ensure they remain within normal ranges.
3. Fluid and blood product administration: Maintaining adequate intravascular volume and oxygen-carrying capacity through the infusion of fluids and blood products as needed.
4. Intraoperative imaging: Utilizing real-time imaging techniques, such as X-ray, ultrasound, or CT scans, to guide the surgical procedure and ensure accurate placement of implants or other devices.
5. Neuromonitoring: Using electrophysiological methods to monitor the functional integrity of nerves and neural structures during surgery, particularly in procedures involving the brain, spine, or peripheral nerves.
6. Intraoperative medication management: Administering various medications as needed for pain control, infection prophylaxis, or the treatment of medical conditions that may arise during the surgery.
7. Temperature management: Regulating the patient's body temperature to prevent hypothermia or hyperthermia, which can have adverse effects on surgical outcomes and overall patient health.
8. Communication and coordination: Ensuring effective communication among the members of the surgical team to optimize patient care and safety.

Alcoholic Liver Cirrhosis is a medical condition characterized by irreversible scarring (fibrosis) and damage to the liver caused by excessive consumption of alcohol over an extended period. The liver's normal structure and function are progressively impaired as healthy liver tissue is replaced by scarred tissue, leading to the formation of nodules (regenerative noduli).

The condition typically develops after years of heavy drinking, with a higher risk for those who consume more than 60 grams of pure alcohol daily. The damage caused by alcoholic liver cirrhosis can be life-threatening and may result in complications such as:

1. Ascites (accumulation of fluid in the abdomen)
2. Encephalopathy (neurological dysfunction due to liver failure)
3. Esophageal varices (dilated veins in the esophagus that can rupture and bleed)
4. Hepatorenal syndrome (kidney failure caused by liver disease)
5. Increased susceptibility to infections
6. Liver cancer (hepatocellular carcinoma)
7. Portal hypertension (increased blood pressure in the portal vein that supplies blood to the liver)

Abstaining from alcohol and managing underlying medical conditions are crucial for slowing down or halting disease progression. Treatment may involve medications, dietary changes, and supportive care to address complications. In severe cases, a liver transplant might be necessary.

Collateral circulation refers to the alternate blood supply routes that bypass an obstructed or narrowed vessel and reconnect with the main vascular system. These collateral vessels can develop over time as a result of the body's natural adaptation to chronic ischemia (reduced blood flow) caused by various conditions such as atherosclerosis, thromboembolism, or vasculitis.

The development of collateral circulation helps maintain adequate blood flow and oxygenation to affected tissues, minimizing the risk of tissue damage and necrosis. In some cases, well-developed collateral circulations can help compensate for significant blockages in major vessels, reducing symptoms and potentially preventing the need for invasive interventions like revascularization procedures. However, the extent and effectiveness of collateral circulation vary from person to person and depend on factors such as age, overall health status, and the presence of comorbidities.

Vasoconstriction is a medical term that refers to the narrowing of blood vessels due to the contraction of the smooth muscle in their walls. This process decreases the diameter of the lumen (the inner space of the blood vessel) and reduces blood flow through the affected vessels. Vasoconstriction can occur throughout the body, but it is most noticeable in the arterioles and precapillary sphincters, which control the amount of blood that flows into the capillary network.

The autonomic nervous system, specifically the sympathetic division, plays a significant role in regulating vasoconstriction through the release of neurotransmitters like norepinephrine (noradrenaline). Various hormones and chemical mediators, such as angiotensin II, endothelin-1, and serotonin, can also induce vasoconstriction.

Vasoconstriction is a vital physiological response that helps maintain blood pressure and regulate blood flow distribution in the body. However, excessive or prolonged vasoconstriction may contribute to several pathological conditions, including hypertension, stroke, and peripheral vascular diseases.

A kidney, in medical terms, is one of two bean-shaped organs located in the lower back region of the body. They are essential for maintaining homeostasis within the body by performing several crucial functions such as:

1. Regulation of water and electrolyte balance: Kidneys help regulate the amount of water and various electrolytes like sodium, potassium, and calcium in the bloodstream to maintain a stable internal environment.

2. Excretion of waste products: They filter waste products from the blood, including urea (a byproduct of protein metabolism), creatinine (a breakdown product of muscle tissue), and other harmful substances that result from normal cellular functions or external sources like medications and toxins.

3. Endocrine function: Kidneys produce several hormones with important roles in the body, such as erythropoietin (stimulates red blood cell production), renin (regulates blood pressure), and calcitriol (activated form of vitamin D that helps regulate calcium homeostasis).

4. pH balance regulation: Kidneys maintain the proper acid-base balance in the body by excreting either hydrogen ions or bicarbonate ions, depending on whether the blood is too acidic or too alkaline.

5. Blood pressure control: The kidneys play a significant role in regulating blood pressure through the renin-angiotensin-aldosterone system (RAAS), which constricts blood vessels and promotes sodium and water retention to increase blood volume and, consequently, blood pressure.

Anatomically, each kidney is approximately 10-12 cm long, 5-7 cm wide, and 3 cm thick, with a weight of about 120-170 grams. They are surrounded by a protective layer of fat and connected to the urinary system through the renal pelvis, ureters, bladder, and urethra.

Renin is a medically recognized term and it is defined as:

"A protein (enzyme) that is produced and released by specialized cells (juxtaglomerular cells) in the kidney. Renin is a key component of the renin-angiotensin-aldosterone system (RAAS), which helps regulate blood pressure and fluid balance in the body.

When the kidney detects a decrease in blood pressure or a reduction in sodium levels, it releases renin into the bloodstream. Renin then acts on a protein called angiotensinogen, converting it to angiotensin I. Angiotensin-converting enzyme (ACE) subsequently converts angiotensin I to angiotensin II, which is a potent vasoconstrictor that narrows blood vessels and increases blood pressure.

Additionally, angiotensin II stimulates the adrenal glands to release aldosterone, a hormone that promotes sodium reabsorption in the kidneys and increases water retention, further raising blood pressure.

Therefore, renin plays a critical role in maintaining proper blood pressure and electrolyte balance in the body."

Heart failure is a pathophysiological state in which the heart is unable to pump sufficient blood to meet the metabolic demands of the body or do so only at the expense of elevated filling pressures. It can be caused by various cardiac disorders, including coronary artery disease, hypertension, valvular heart disease, cardiomyopathy, and arrhythmias. Symptoms may include shortness of breath, fatigue, and fluid retention. Heart failure is often classified based on the ejection fraction (EF), which is the percentage of blood that is pumped out of the left ventricle during each contraction. A reduced EF (less than 40%) is indicative of heart failure with reduced ejection fraction (HFrEF), while a preserved EF (greater than or equal to 50%) is indicative of heart failure with preserved ejection fraction (HFpEF). There is also a category of heart failure with mid-range ejection fraction (HFmrEF) for those with an EF between 40-49%.

Pathological constriction refers to an abnormal narrowing or tightening of a body passage or organ, which can interfere with the normal flow of blood, air, or other substances through the area. This constriction can occur due to various reasons such as inflammation, scarring, or abnormal growths, and can affect different parts of the body, including blood vessels, airways, intestines, and ureters. Pathological constriction can lead to a range of symptoms and complications depending on its location and severity, and may require medical intervention to correct.

A portosystemic shunt is a surgical procedure that creates a connection between the portal vein (the blood vessel that carries blood from the digestive organs to the liver) and another systemic vein (a vein that carries blood away from the liver). This procedure is typically performed in animals, particularly dogs, to treat conditions such as portal hypertension or liver disease.

In a surgical portosystemic shunt, the surgeon creates a connection between the portal vein and a systemic vein, allowing blood from the digestive organs to bypass the liver. This can help to reduce the pressure in the portal vein and improve blood flow to the liver. The specific type of shunt created and the surgical approach used may vary depending on the individual patient's needs and the surgeon's preference.

It is important to note that while a surgical portosystemic shunt can be an effective treatment for certain conditions, it is not without risks and potential complications. As with any surgical procedure, there is always a risk of infection, bleeding, or other complications. Additionally, the creation of a portosystemic shunt can have long-term effects on the liver and overall health of the patient. It is important for pet owners to carefully consider the risks and benefits of this procedure and to discuss any questions or concerns they may have with their veterinarian.

Vasodilator agents are pharmacological substances that cause the relaxation or widening of blood vessels by relaxing the smooth muscle in the vessel walls. This results in an increase in the diameter of the blood vessels, which decreases vascular resistance and ultimately reduces blood pressure. Vasodilators can be further classified based on their site of action:

1. Systemic vasodilators: These agents cause a generalized relaxation of the smooth muscle in the walls of both arteries and veins, resulting in a decrease in peripheral vascular resistance and preload (the volume of blood returning to the heart). Examples include nitroglycerin, hydralazine, and calcium channel blockers.
2. Arterial vasodilators: These agents primarily affect the smooth muscle in arterial vessel walls, leading to a reduction in afterload (the pressure against which the heart pumps blood). Examples include angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and direct vasodilators like sodium nitroprusside.
3. Venous vasodilators: These agents primarily affect the smooth muscle in venous vessel walls, increasing venous capacitance and reducing preload. Examples include nitroglycerin and other organic nitrates.

Vasodilator agents are used to treat various cardiovascular conditions such as hypertension, heart failure, angina, and pulmonary arterial hypertension. It is essential to monitor their use carefully, as excessive vasodilation can lead to orthostatic hypotension, reflex tachycardia, or fluid retention.

Cesium is a chemical element with the atomic number 55 and the symbol Cs. There are several isotopes of cesium, which are variants of the element that have different numbers of neutrons in their nuclei. The most stable and naturally occurring cesium isotope is cesium-133, which has 78 neutrons and a half-life of more than 3 x 10^20 years (effectively stable).

However, there are also radioactive isotopes of cesium, including cesium-134 and cesium-137. Cesium-134 has a half-life of about 2 years, while cesium-137 has a half-life of about 30 years. These isotopes are produced naturally in trace amounts by the decay of uranium and thorium in the Earth's crust, but they can also be produced artificially in nuclear reactors and nuclear weapons tests.

Cesium isotopes are commonly used in medical research and industrial applications. For example, cesium-137 is used as a radiation source in cancer therapy and industrial radiography. However, exposure to high levels of radioactive cesium can be harmful to human health, causing symptoms such as nausea, vomiting, diarrhea, and potentially more serious effects such as damage to the central nervous system and an increased risk of cancer.

Cerebrovascular circulation refers to the network of blood vessels that supply oxygenated blood and nutrients to the brain tissue, and remove waste products. It includes the internal carotid arteries, vertebral arteries, circle of Willis, and the intracranial arteries that branch off from them.

The internal carotid arteries and vertebral arteries merge to form the circle of Willis, a polygonal network of vessels located at the base of the brain. The anterior cerebral artery, middle cerebral artery, posterior cerebral artery, and communicating arteries are the major vessels that branch off from the circle of Willis and supply blood to different regions of the brain.

Interruptions or abnormalities in the cerebrovascular circulation can lead to various neurological conditions such as stroke, transient ischemic attack (TIA), and vascular dementia.

Propranolol is a medication that belongs to a class of drugs called beta blockers. Medically, it is defined as a non-selective beta blocker, which means it blocks the effects of both epinephrine (adrenaline) and norepinephrine (noradrenaline) on the heart and other organs. These effects include reducing heart rate, contractility, and conduction velocity, leading to decreased oxygen demand by the myocardium. Propranolol is used in the management of various conditions such as hypertension, angina pectoris, arrhythmias, essential tremor, anxiety disorders, and infants with congenital heart defects. It may also be used to prevent migraines and reduce the risk of future heart attacks. As with any medication, it should be taken under the supervision of a healthcare provider due to potential side effects and contraindications.

Hematocrit is a medical term that refers to the percentage of total blood volume that is made up of red blood cells. It is typically measured as part of a complete blood count (CBC) test. A high hematocrit may indicate conditions such as dehydration, polycythemia, or living at high altitudes, while a low hematocrit may be a sign of anemia, bleeding, or overhydration. It is important to note that hematocrit values can vary depending on factors such as age, gender, and pregnancy status.

Aqueous humor is a clear, watery fluid that fills the anterior and posterior chambers of the eye. It is produced by the ciliary processes in the posterior chamber and circulates through the pupil into the anterior chamber, where it provides nutrients to the cornea and lens, maintains intraocular pressure, and helps to shape the eye. The aqueous humor then drains out of the eye through the trabecular meshwork and into the canal of Schlemm, eventually reaching the venous system.

Blood gas analysis is a medical test that measures the levels of oxygen and carbon dioxide in the blood, as well as the pH level, which indicates the acidity or alkalinity of the blood. This test is often used to evaluate lung function, respiratory disorders, and acid-base balance in the body. It can also be used to monitor the effectiveness of treatments for conditions such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory illnesses. The analysis is typically performed on a sample of arterial blood, although venous blood may also be used in some cases.

Microcirculation is the circulation of blood in the smallest blood vessels, including arterioles, venules, and capillaries. It's responsible for the delivery of oxygen and nutrients to the tissues and the removal of waste products. The microcirculation plays a crucial role in maintaining tissue homeostasis and is regulated by various physiological mechanisms such as autonomic nervous system activity, local metabolic factors, and hormones.

Impairment of microcirculation can lead to tissue hypoxia, inflammation, and organ dysfunction, which are common features in several diseases, including diabetes, hypertension, sepsis, and ischemia-reperfusion injury. Therefore, understanding the structure and function of the microcirculation is essential for developing new therapeutic strategies to treat these conditions.

A pulse is a medical term that refers to the tactile sensation of the heartbeat that can be felt in various parts of the body, most commonly at the wrist, neck, or groin. It is caused by the surge of blood through an artery as the heart pushes blood out into the body during systole (contraction). The pulse can provide important information about a person's heart rate, rhythm, and strength, which are all crucial vital signs that help healthcare professionals assess a patient's overall health and identify any potential medical issues.

In summary, a pulse is a palpable manifestation of the heartbeat felt in an artery due to the ejection of blood by the heart during systole.

Lymph is a colorless, transparent fluid that circulates throughout the lymphatic system, which is a part of the immune and circulatory systems. It consists of white blood cells called lymphocytes, proteins, lipids, glucose, electrolytes, hormones, and waste products. Lymph plays an essential role in maintaining fluid balance, absorbing fats from the digestive tract, and defending the body against infection by transporting immune cells to various tissues and organs. It is collected from tissues through lymph capillaries and flows through increasingly larger lymphatic vessels, ultimately returning to the bloodstream via the subclavian veins in the chest region.

Sodium Chloride is defined as the inorganic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. It is commonly known as table salt or halite, and it is used extensively in food seasoning and preservation due to its ability to enhance flavor and inhibit bacterial growth. In medicine, sodium chloride is used as a balanced electrolyte solution for rehydration and as a topical wound irrigant and antiseptic. It is also an essential component of the human body's fluid balance and nerve impulse transmission.

Atrial natriuretic factor (ANF), also known as atrial natriuretic peptide (ANP), is a hormone that is primarily produced and secreted by the atria of the heart in response to stretching of the cardiac muscle cells due to increased blood volume. ANF plays a crucial role in regulating body fluid homeostasis, blood pressure, and cardiovascular function.

The main physiological action of ANF is to promote sodium and water excretion by the kidneys, which helps lower blood volume and reduce blood pressure. ANF also relaxes vascular smooth muscle, dilates blood vessels, and inhibits the renin-angiotensin-aldosterone system (RAAS), further contributing to its blood pressure-lowering effects.

Defects in ANF production or action have been implicated in several cardiovascular disorders, including heart failure, hypertension, and kidney disease. Therefore, ANF and its analogs are being investigated as potential therapeutic agents for the treatment of these conditions.

Swan-Ganz catheterization is a medical procedure in which a Swan-Ganz catheter, also known as a pulmonary artery catheter, is inserted into a patient's vein and guided through the heart to the pulmonary artery. The procedure is named after its inventors, Dr. Jeremy Swan and Dr. William Ganz.

The Swan-Ganz catheter is a thin, flexible tube that is equipped with sensors that measure various cardiac functions, such as blood pressure in the heart chambers and lungs, oxygen saturation of the blood, and cardiac output. This information helps doctors evaluate heart function, diagnose heart conditions, and monitor treatment effectiveness.

Swan-Ganz catheterization is typically performed in a hospital setting by trained medical professionals, such as cardiologists or critical care specialists. The procedure may be used to diagnose and manage various heart conditions, including heart failure, pulmonary hypertension, and shock. It may also be used during major surgeries or other medical procedures to monitor the patient's hemodynamic status.

Like any medical procedure, Swan-Ganz catheterization carries some risks, such as infection, bleeding, and damage to blood vessels or heart structures. However, these complications are relatively rare when the procedure is performed by experienced medical professionals.

Cerebral veins are the blood vessels that carry deoxygenated blood from the brain to the dural venous sinuses, which are located between the layers of tissue covering the brain. The largest cerebral vein is the superior sagittal sinus, which runs along the top of the brain. Other major cerebral veins include the straight sinus, transverse sinus, sigmoid sinus, and cavernous sinus. These veins receive blood from smaller veins called venules that drain the surface and deep structures of the brain. The cerebral veins play an important role in maintaining normal circulation and pressure within the brain.

Coronary circulation refers to the circulation of blood in the coronary vessels, which supply oxygenated blood to the heart muscle (myocardium) and drain deoxygenated blood from it. The coronary circulation system includes two main coronary arteries - the left main coronary artery and the right coronary artery - that branch off from the aorta just above the aortic valve. These arteries further divide into smaller branches, which supply blood to different regions of the heart muscle.

The left main coronary artery divides into two branches: the left anterior descending (LAD) artery and the left circumflex (LCx) artery. The LAD supplies blood to the front and sides of the heart, while the LCx supplies blood to the back and sides of the heart. The right coronary artery supplies blood to the lower part of the heart, including the right ventricle and the bottom portion of the left ventricle.

The veins that drain the heart muscle include the great cardiac vein, the middle cardiac vein, and the small cardiac vein, which merge to form the coronary sinus. The coronary sinus empties into the right atrium, allowing deoxygenated blood to enter the right side of the heart and be pumped to the lungs for oxygenation.

Coronary circulation is essential for maintaining the health and function of the heart muscle, as it provides the necessary oxygen and nutrients required for proper contraction and relaxation of the myocardium. Any disruption or blockage in the coronary circulation system can lead to serious consequences, such as angina, heart attack, or even death.

Cardiac catheterization is a medical procedure used to diagnose and treat cardiovascular conditions. In this procedure, a thin, flexible tube called a catheter is inserted into a blood vessel in the arm or leg and threaded up to the heart. The catheter can be used to perform various diagnostic tests, such as measuring the pressure inside the heart chambers and assessing the function of the heart valves.

Cardiac catheterization can also be used to treat certain cardiovascular conditions, such as narrowed or blocked arteries. In these cases, a balloon or stent may be inserted through the catheter to open up the blood vessel and improve blood flow. This procedure is known as angioplasty or percutaneous coronary intervention (PCI).

Cardiac catheterization is typically performed in a hospital cardiac catheterization laboratory by a team of healthcare professionals, including cardiologists, radiologists, and nurses. The procedure may be done under local anesthesia with sedation or general anesthesia, depending on the individual patient's needs and preferences.

Overall, cardiac catheterization is a valuable tool in the diagnosis and treatment of various heart conditions, and it can help improve symptoms, reduce complications, and prolong life for many patients.

Artificial respiration is an emergency procedure that can be used to provide oxygen to a person who is not breathing or is breathing inadequately. It involves manually forcing air into the lungs, either by compressing the chest or using a device to deliver breaths. The goal of artificial respiration is to maintain adequate oxygenation of the body's tissues and organs until the person can breathe on their own or until advanced medical care arrives. Artificial respiration may be used in conjunction with cardiopulmonary resuscitation (CPR) in cases of cardiac arrest.

Intra-abdominal hypertension (IAH) is an abnormal increase in the pressure within the abdominal cavity, typically defined as a sustained or repeated pathological elevation in the intravesical pressure greater than 12 mmHg (millimeters of mercury). It can lead to reduced blood flow to organs in the abdomen and can cause serious complications if not properly managed.

The causes of IAH are varied, including conditions such as ascites, liver disease, intra-abdominal infection or inflammation, trauma, and abdominal surgery. In some cases, it may also be caused by the use of certain medications that can affect abdominal muscle tone or fluid balance.

IAH is often classified into four grades based on the degree of pressure elevation: Grade I (12-15 mmHg), Grade II (16-20 mmHg), Grade III (21-25 mmHg), and Grade IV (>25 mmHg).

If left untreated, IAH can lead to a number of serious complications, including organ dysfunction, respiratory compromise, decreased cardiac output, and even death. Treatment typically involves addressing the underlying cause of the pressure elevation, as well as supportive measures such as fluid management, decompressive laparotomy, or use of abdominal drains.

Catheterization is a medical procedure in which a catheter (a flexible tube) is inserted into the body to treat various medical conditions or for diagnostic purposes. The specific definition can vary depending on the area of medicine and the particular procedure being discussed. Here are some common types of catheterization:

1. Urinary catheterization: This involves inserting a catheter through the urethra into the bladder to drain urine. It is often performed to manage urinary retention, monitor urine output in critically ill patients, or assist with surgical procedures.
2. Cardiac catheterization: A procedure where a catheter is inserted into a blood vessel, usually in the groin or arm, and guided to the heart. This allows for various diagnostic tests and treatments, such as measuring pressures within the heart chambers, assessing blood flow, or performing angioplasty and stenting of narrowed coronary arteries.
3. Central venous catheterization: A catheter is inserted into a large vein, typically in the neck, chest, or groin, to administer medications, fluids, or nutrition, or to monitor central venous pressure.
4. Peritoneal dialysis catheterization: A catheter is placed into the abdominal cavity for individuals undergoing peritoneal dialysis, a type of kidney replacement therapy.
5. Neurological catheterization: In some cases, a catheter may be inserted into the cerebrospinal fluid space (lumbar puncture) or the brain's ventricular system (ventriculostomy) to diagnose or treat various neurological conditions.

These are just a few examples of catheterization procedures in medicine. The specific definition and purpose will depend on the medical context and the particular organ or body system involved.

Hepatectomy is a surgical procedure that involves the removal of part or all of the liver. This procedure can be performed for various reasons, such as removing cancerous or non-cancerous tumors, treating liver trauma, or donating a portion of the liver to another person in need of a transplant (live donor hepatectomy). The extent of the hepatectomy depends on the medical condition and overall health of the patient. It is a complex procedure that requires significant expertise and experience from the surgical team due to the liver's unique anatomy, blood supply, and regenerative capabilities.

Manometry is a medical test that measures pressure inside various parts of the gastrointestinal tract. It is often used to help diagnose digestive disorders such as achalasia, gastroparesis, and irritable bowel syndrome. During the test, a thin, flexible tube called a manometer is inserted through the mouth or rectum and into the area being tested. The tube is connected to a machine that measures and records pressure readings. These readings can help doctors identify any abnormalities in muscle function or nerve reflexes within the digestive tract.

Atrial function in a medical context refers to the role and performance of the two upper chambers of the heart, known as the atria. The main functions of the atria are to receive blood from the veins and help pump it into the ventricles, which are the lower pumping chambers of the heart.

The atria contract in response to electrical signals generated by the sinoatrial node, which is the heart's natural pacemaker. This contraction helps to fill the ventricles with blood before they contract and pump blood out to the rest of the body. Atrial function can be assessed through various diagnostic tests, such as echocardiograms or electrocardiograms (ECGs), which can help identify any abnormalities in atrial structure or electrical activity that may affect heart function.

Surgical blood loss is the amount of blood that is lost during a surgical procedure. It can occur through various routes such as incisions, punctures or during the removal of organs or tissues. The amount of blood loss can vary widely depending on the type and complexity of the surgery being performed.

Surgical blood loss can be classified into three categories:

1. Insensible losses: These are small amounts of blood that are lost through the skin, respiratory tract, or gastrointestinal tract during surgery. They are not usually significant enough to cause any clinical effects.
2. Visible losses: These are larger amounts of blood that can be seen and measured directly during surgery. They may require transfusion or other interventions to prevent hypovolemia (low blood volume) and its complications.
3. Hidden losses: These are internal bleeding that cannot be easily seen or measured during surgery. They can occur in the abdominal cavity, retroperitoneal space, or other areas of the body. They may require further exploration or imaging studies to diagnose and manage.

Surgical blood loss can lead to several complications such as hypovolemia, anemia, coagulopathy (disorders of blood clotting), and organ dysfunction. Therefore, it is essential to monitor and manage surgical blood loss effectively to ensure optimal patient outcomes.

Nadolol is a non-selective beta blocker medication that works by blocking the action of certain natural substances such as adrenaline (epinephrine) on the heart and blood vessels. This results in a decrease in heart rate, heart contractions strength, and lowering of blood pressure. Nadolol is used to treat high blood pressure, angina (chest pain), irregular heartbeats, and to prevent migraines. It may also be used for other conditions as determined by your doctor.

Nadolol is available in oral tablet form and is typically taken once a day. The dosage will depend on the individual's medical condition, response to treatment, and any other medications they may be taking. Common side effects of Nadolol include dizziness, lightheadedness, tiredness, and weakness. Serious side effects are rare but can occur, such as slow or irregular heartbeat, shortness of breath, swelling of the hands or feet, mental/mood changes, and unusual weight gain.

It is important to follow your doctor's instructions carefully when taking Nadolol, and to inform them of any other medications you are taking, as well as any medical conditions you may have, such as diabetes, asthma, or liver disease. Additionally, it is recommended to avoid sudden discontinuation of the medication without consulting with your healthcare provider, as this can lead to withdrawal symptoms such as increased heart rate and blood pressure.

Respiratory mechanics refers to the biomechanical properties and processes that involve the movement of air through the respiratory system during breathing. It encompasses the mechanical behavior of the lungs, chest wall, and the muscles of respiration, including the diaphragm and intercostal muscles.

Respiratory mechanics includes several key components:

1. **Compliance**: The ability of the lungs and chest wall to expand and recoil during breathing. High compliance means that the structures can easily expand and recoil, while low compliance indicates greater resistance to expansion and recoil.
2. **Resistance**: The opposition to airflow within the respiratory system, primarily due to the friction between the air and the airway walls. Airway resistance is influenced by factors such as airway diameter, length, and the viscosity of the air.
3. **Lung volumes and capacities**: These are the amounts of air present in the lungs during different phases of the breathing cycle. They include tidal volume (the amount of air inspired or expired during normal breathing), inspiratory reserve volume (additional air that can be inspired beyond the tidal volume), expiratory reserve volume (additional air that can be exhaled beyond the tidal volume), and residual volume (the air remaining in the lungs after a forced maximum exhalation).
4. **Work of breathing**: The energy required to overcome the resistance and elastic forces during breathing. This work is primarily performed by the respiratory muscles, which contract to generate negative intrathoracic pressure and expand the chest wall, allowing air to flow into the lungs.
5. **Pressure-volume relationships**: These describe how changes in lung volume are associated with changes in pressure within the respiratory system. Important pressure components include alveolar pressure (the pressure inside the alveoli), pleural pressure (the pressure between the lungs and the chest wall), and transpulmonary pressure (the difference between alveolar and pleural pressures).

Understanding respiratory mechanics is crucial for diagnosing and managing various respiratory disorders, such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

Orthostatic intolerance is a condition in which an individual experiences lightheadedness, dizziness, or fainting when standing or maintaining an upright position for extended periods. It is caused by an abnormal physiological response to gravity and results in inadequate blood flow to the brain upon standing.

The medical definition of orthostatic intolerance includes symptoms that are exacerbated by upright posture and relieved by recumbent (lying down) position. The underlying mechanisms involve dysfunction in the autonomic nervous system, which controls involuntary bodily functions such as heart rate, blood pressure, and vasoconstriction.

Orthostatic intolerance can be a symptom of various medical conditions, including postural orthostatic tachycardia syndrome (POTS), neurogenic orthostatic hypotension, and other autonomic disorders. Proper diagnosis and management require a thorough evaluation by a healthcare professional to identify the underlying cause and develop an appropriate treatment plan.

Epinephrine, also known as adrenaline, is a hormone and a neurotransmitter that is produced in the body. It is released by the adrenal glands in response to stress or excitement, and it prepares the body for the "fight or flight" response. Epinephrine works by binding to specific receptors in the body, which causes a variety of physiological effects, including increased heart rate and blood pressure, improved muscle strength and alertness, and narrowing of the blood vessels in the skin and intestines. It is also used as a medication to treat various medical conditions, such as anaphylaxis (a severe allergic reaction), cardiac arrest, and low blood pressure.

Reference values, also known as reference ranges or reference intervals, are the set of values that are considered normal or typical for a particular population or group of people. These values are often used in laboratory tests to help interpret test results and determine whether a patient's value falls within the expected range.

The process of establishing reference values typically involves measuring a particular biomarker or parameter in a large, healthy population and then calculating the mean and standard deviation of the measurements. Based on these statistics, a range is established that includes a certain percentage of the population (often 95%) and excludes extreme outliers.

It's important to note that reference values can vary depending on factors such as age, sex, race, and other demographic characteristics. Therefore, it's essential to use reference values that are specific to the relevant population when interpreting laboratory test results. Additionally, reference values may change over time due to advances in measurement technology or changes in the population being studied.

The lymphatic system is a complex network of organs, tissues, vessels, and cells that work together to defend the body against infectious diseases and also play a crucial role in the immune system. It is made up of:

1. Lymphoid Organs: These include the spleen, thymus, lymph nodes, tonsils, adenoids, and Peyer's patches (in the intestines). They produce and mature immune cells.

2. Lymphatic Vessels: These are thin tubes that carry clear fluid called lymph towards the heart.

3. Lymph: This is a clear-to-white fluid that contains white blood cells, mainly lymphocytes, which help fight infections.

4. Other tissues and cells: These include bone marrow where immune cells are produced, and lymphocytes (T cells and B cells) which are types of white blood cells that help protect the body from infection and disease.

The primary function of the lymphatic system is to transport lymph throughout the body, collecting waste products, bacteria, viruses, and other foreign substances from the tissues, and filtering them out through the lymph nodes. The lymphatic system also helps in the absorption of fats and fat-soluble vitamins from food in the digestive tract.

Postoperative care refers to the comprehensive medical treatment and nursing attention provided to a patient following a surgical procedure. The goal of postoperative care is to facilitate the patient's recovery, prevent complications, manage pain, ensure proper healing of the incision site, and maintain overall health and well-being until the patient can resume their normal activities.

This type of care includes monitoring vital signs, managing pain through medication or other techniques, ensuring adequate hydration and nutrition, helping the patient with breathing exercises to prevent lung complications, encouraging mobility to prevent blood clots, monitoring for signs of infection or other complications, administering prescribed medications, providing wound care, and educating the patient about postoperative care instructions.

The duration of postoperative care can vary depending on the type and complexity of the surgical procedure, as well as the individual patient's needs and overall health status. It may be provided in a hospital setting, an outpatient surgery center, or in the patient's home, depending on the level of care required.

Water-electrolyte balance refers to the regulation of water and electrolytes (sodium, potassium, chloride, bicarbonate) in the body to maintain homeostasis. This is crucial for various bodily functions such as nerve impulse transmission, muscle contraction, fluid balance, and pH regulation. The body maintains this balance through mechanisms that control water intake, excretion, and electrolyte concentration in various body fluids like blood and extracellular fluid. Disruptions in water-electrolyte balance can lead to dehydration or overhydration, and imbalances in electrolytes can cause conditions such as hyponatremia (low sodium levels) or hyperkalemia (high potassium levels).

Oxygen consumption, also known as oxygen uptake, is the amount of oxygen that is consumed or utilized by the body during a specific period of time, usually measured in liters per minute (L/min). It is a common measurement used in exercise physiology and critical care medicine to assess an individual's aerobic metabolism and overall health status.

In clinical settings, oxygen consumption is often measured during cardiopulmonary exercise testing (CPET) to evaluate cardiovascular function, pulmonary function, and exercise capacity in patients with various medical conditions such as heart failure, chronic obstructive pulmonary disease (COPD), and other respiratory or cardiac disorders.

During exercise, oxygen is consumed by the muscles to generate energy through a process called oxidative phosphorylation. The amount of oxygen consumed during exercise can provide important information about an individual's fitness level, exercise capacity, and overall health status. Additionally, measuring oxygen consumption can help healthcare providers assess the effectiveness of treatments and rehabilitation programs in patients with various medical conditions.

Hemodilution is a medical term that refers to the reduction in the concentration of certain components in the blood, usually referring to red blood cells (RBCs) or hemoglobin. This occurs when an individual's plasma volume expands due to the infusion of intravenous fluids or the body's own production of fluid, such as during severe infection or inflammation. As a result, the number of RBCs per unit of blood decreases, leading to a lower hematocrit and hemoglobin level. It is important to note that while hemodilution reduces the concentration of RBCs in the blood, it does not necessarily indicate anemia or blood loss.

The saphenous vein is a term used in anatomical description to refer to the great or small saphenous veins, which are superficial veins located in the lower extremities of the human body.

The great saphenous vein (GSV) is the longest vein in the body and originates from the medial aspect of the foot, ascending along the medial side of the leg and thigh, and drains into the femoral vein at the saphenofemoral junction, located in the upper third of the thigh.

The small saphenous vein (SSV) is a shorter vein that originates from the lateral aspect of the foot, ascends along the posterior calf, and drains into the popliteal vein at the saphenopopliteal junction, located in the popliteal fossa.

These veins are often used as conduits for coronary artery bypass grafting (CABG) surgery due to their consistent anatomy and length.

Capillary permeability refers to the ability of substances to pass through the walls of capillaries, which are the smallest blood vessels in the body. These tiny vessels connect the arterioles and venules, allowing for the exchange of nutrients, waste products, and gases between the blood and the surrounding tissues.

The capillary wall is composed of a single layer of endothelial cells that are held together by tight junctions. The permeability of these walls varies depending on the size and charge of the molecules attempting to pass through. Small, uncharged molecules such as water, oxygen, and carbon dioxide can easily diffuse through the capillary wall, while larger or charged molecules such as proteins and large ions have more difficulty passing through.

Increased capillary permeability can occur in response to inflammation, infection, or injury, allowing larger molecules and immune cells to enter the surrounding tissues. This can lead to swelling (edema) and tissue damage if not controlled. Decreased capillary permeability, on the other hand, can lead to impaired nutrient exchange and tissue hypoxia.

Overall, the permeability of capillaries is a critical factor in maintaining the health and function of tissues throughout the body.

Artificial pneumoperitoneum is a medical condition that refers to the presence of air or gas in the peritoneal cavity, which is the space between the lining of the abdominal wall and the organs within the abdomen. This condition is typically created intentionally during surgical procedures, such as laparoscopy, to provide a working space for the surgeon to perform the operation.

During laparoscopic surgery, a thin tube called a trocar is inserted through a small incision in the abdominal wall, and carbon dioxide gas is pumped into the peritoneal cavity to create a pneumoperitoneum. This allows the surgeon to insert specialized instruments through other small incisions and perform the surgery while visualizing the operative field with a camera.

While artificial pneumoperitoneum is generally safe, there are potential complications that can arise, such as injury to surrounding organs or blood vessels during trocar insertion, subcutaneous emphysema (air trapped under the skin), or gas embolism (gas in the bloodstream). These risks are typically minimized through careful technique and monitoring during the procedure.

Protein-losing enteropathies (PLE) refer to a group of conditions characterized by excessive loss of proteins from the gastrointestinal tract into the intestinal lumen and ultimately into the stool. This results in hypoproteinemia, which is a decrease in the concentration of proteins in the bloodstream, particularly albumin.

The protein loss can occur due to various reasons such as increased permeability of the intestinal mucosa, lymphatic obstruction, or inflammatory processes affecting the gastrointestinal tract. Common causes of PLE include conditions such as inflammatory bowel disease, intestinal lymphangiectasia, celiac disease, Whipple's disease, and menetrier's disease.

Symptoms of PLE may include edema, ascites, weight loss, diarrhea, and fatigue. The diagnosis of PLE typically involves measuring the concentration of proteins in the stool, as well as other diagnostic tests to determine the underlying cause. Treatment of PLE depends on the underlying cause and may involve dietary modifications, medications, or surgical interventions.

Analysis of Variance (ANOVA) is a statistical technique used to compare the means of two or more groups and determine whether there are any significant differences between them. It is a way to analyze the variance in a dataset to determine whether the variability between groups is greater than the variability within groups, which can indicate that the groups are significantly different from one another.

ANOVA is based on the concept of partitioning the total variance in a dataset into two components: variance due to differences between group means (also known as "between-group variance") and variance due to differences within each group (also known as "within-group variance"). By comparing these two sources of variance, ANOVA can help researchers determine whether any observed differences between groups are statistically significant, or whether they could have occurred by chance.

ANOVA is a widely used technique in many areas of research, including biology, psychology, engineering, and business. It is often used to compare the means of two or more experimental groups, such as a treatment group and a control group, to determine whether the treatment had a significant effect. ANOVA can also be used to compare the means of different populations or subgroups within a population, to identify any differences that may exist between them.

The axillary vein is a large vein that runs through the axilla or armpit region. It is formed by the union of the brachial vein and the basilic vein at the lower border of the teres major muscle. The axillary vein carries deoxygenated blood from the upper limb, chest wall, and breast towards the heart. As it moves proximally, it becomes continuous with the subclavian vein to form the brachiocephalic vein. It is accompanied by the axillary artery and forms part of the important neurovascular bundle in the axilla.

Ligation, in the context of medical terminology, refers to the process of tying off a part of the body, usually blood vessels or tissue, with a surgical suture or another device. The goal is to stop the flow of fluids such as blood or other substances within the body. It is commonly used during surgeries to control bleeding or to block the passage of fluids, gases, or solids in various parts of the body.

Continuous Positive Airway Pressure (CPAP) is a mode of non-invasive ventilation that delivers pressurized room air or oxygen to maintain airway patency and increase functional residual capacity in patients with respiratory disorders. A CPAP device, which typically includes a flow generator, tubing, and a mask, provides a constant positive pressure throughout the entire respiratory cycle, preventing the collapse of the upper airway during inspiration and expiration.

CPAP is commonly used to treat obstructive sleep apnea (OSA), a condition characterized by repetitive narrowing or closure of the upper airway during sleep, leading to intermittent hypoxia, hypercapnia, and sleep fragmentation. By delivering positive pressure, CPAP helps to stent open the airway, ensuring unobstructed breathing and reducing the frequency and severity of apneic events.

Additionally, CPAP can be used in other clinical scenarios, such as managing acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD) exacerbations, or postoperative respiratory insufficiency, to improve oxygenation and reduce the work of breathing. The specific pressure settings and device configurations are tailored to each patient's needs based on their underlying condition, severity of symptoms, and response to therapy.

Sclerotherapy is a medical procedure used to treat varicose veins and spider veins. It involves the injection of a solution (called a sclerosant) directly into the affected vein, which causes the vein to collapse and eventually fade away. The sclerosant works by irritating the lining of the vein, causing it to swell and stick together, which then leads to clotting and the eventual reabsorption of the vein by the body.

The procedure is typically performed in a doctor's office or outpatient setting and may require multiple sessions depending on the severity and number of veins being treated. Common side effects include bruising, swelling, and discomfort at the injection site, as well as the possibility of developing brownish pigmentation or small ulcers near the treatment area. However, these side effects are usually temporary and resolve on their own within a few weeks.

Sclerotherapy is considered a safe and effective treatment for varicose veins and spider veins, with high success rates and low complication rates. It is important to note that while sclerotherapy can improve the appearance of affected veins, it does not prevent new veins from developing in the future.

Plasma volume refers to the total amount of plasma present in an individual's circulatory system. Plasma is the fluid component of blood, in which cells and chemical components are suspended. It is composed mainly of water, along with various dissolved substances such as nutrients, waste products, hormones, gases, and proteins.

Plasma volume is a crucial factor in maintaining proper blood flow, regulating body temperature, and facilitating the transportation of oxygen, carbon dioxide, and other essential components throughout the body. The average plasma volume for an adult human is approximately 3 liters, but it can vary depending on factors like age, sex, body weight, and overall health status.

Changes in plasma volume can have significant effects on an individual's cardiovascular function and fluid balance. For example, dehydration or blood loss can lead to a decrease in plasma volume, while conditions such as heart failure or liver cirrhosis may result in increased plasma volume due to fluid retention. Accurate measurement of plasma volume is essential for diagnosing various medical conditions and monitoring the effectiveness of treatments.

Cardiopulmonary bypass (CPB) is a medical procedure that temporarily takes over the functions of the heart and lungs during major heart surgery. It allows the surgeon to operate on a still, bloodless heart.

During CPB, the patient's blood is circulated outside the body with the help of a heart-lung machine. The machine pumps the blood through a oxygenator, where it is oxygenated and then returned to the body. This bypasses the heart and lungs, hence the name "cardiopulmonary bypass."

CPB involves several components, including a pump, oxygenator, heat exchanger, and tubing. The patient's blood is drained from the heart through cannulas (tubes) and passed through the oxygenator, where it is oxygenated and carbon dioxide is removed. The oxygenated blood is then warmed to body temperature in a heat exchanger before being pumped back into the body.

While on CPB, the patient's heart is stopped with the help of cardioplegia solution, which is infused directly into the coronary arteries. This helps to protect the heart muscle during surgery. The surgeon can then operate on a still and bloodless heart, allowing for more precise surgical repair.

After the surgery is complete, the patient is gradually weaned off CPB, and the heart is restarted with the help of electrical stimulation or medication. The patient's condition is closely monitored during this time to ensure that their heart and lungs are functioning properly.

While CPB has revolutionized heart surgery and allowed for more complex procedures to be performed, it is not without risks. These include bleeding, infection, stroke, kidney damage, and inflammation. However, with advances in technology and technique, the risks associated with CPB have been significantly reduced over time.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

nitroprusside (ni-troe-rus-ide)

A rapid-acting vasodilator used in the management of severe hypertension, acute heart failure, and to reduce afterload in patients undergoing cardiac surgery. It is a potent arterial and venous dilator that decreases preload and afterload, thereby reducing myocardial oxygen demand. Nitroprusside is metabolized to cyanide, which must be monitored closely during therapy to prevent toxicity.

Pharmacologic class: Peripheral vasodilators

Therapeutic class: Antihypertensives, Vasodilators

Medical Categories: Cardiovascular Drugs, Hypertension Agents

Vasoconstrictor agents are substances that cause the narrowing of blood vessels by constricting the smooth muscle in their walls. This leads to an increase in blood pressure and a decrease in blood flow. They work by activating the sympathetic nervous system, which triggers the release of neurotransmitters such as norepinephrine and epinephrine that bind to alpha-adrenergic receptors on the smooth muscle cells of the blood vessel walls, causing them to contract.

Vasoconstrictor agents are used medically for a variety of purposes, including:

* Treating hypotension (low blood pressure)
* Controlling bleeding during surgery or childbirth
* Relieving symptoms of nasal congestion in conditions such as the common cold or allergies

Examples of vasoconstrictor agents include phenylephrine, oxymetazoline, and epinephrine. It's important to note that prolonged use or excessive doses of vasoconstrictor agents can lead to rebound congestion and other adverse effects, so they should be used with caution and under the guidance of a healthcare professional.

Cardiac tamponade is a serious medical condition that occurs when there is excessive fluid or blood accumulation in the pericardial sac, which surrounds the heart. This accumulation puts pressure on the heart, preventing it from filling properly and reducing its ability to pump blood effectively. As a result, cardiac output decreases, leading to symptoms such as low blood pressure, shortness of breath, chest pain, and a rapid pulse. If left untreated, cardiac tamponade can be life-threatening, requiring emergency medical intervention to drain the fluid and relieve the pressure on the heart.

Epidural anesthesia is a type of regional anesthesia that involves the injection of local anesthetic medication into the epidural space in the spine, which is the space surrounding the dura mater, a membrane that covers the spinal cord. The injection is typically administered through a catheter placed in the lower back using a needle.

The local anesthetic drug blocks nerve impulses from the affected area, numbing it and relieving pain. Epidural anesthesia can be used for various surgical procedures, such as cesarean sections, knee or hip replacements, and hernia repairs. It is also commonly used during childbirth to provide pain relief during labor and delivery.

The effects of epidural anesthesia can vary depending on the dose and type of medication used, as well as the individual's response to the drug. The anesthetic may take several minutes to start working, and its duration of action can range from a few hours to a day or more. Epidural anesthesia is generally considered safe when administered by trained medical professionals, but like any medical procedure, it carries some risks, including infection, bleeding, nerve damage, and respiratory depression.

Follow-up studies are a type of longitudinal research that involve repeated observations or measurements of the same variables over a period of time, in order to understand their long-term effects or outcomes. In medical context, follow-up studies are often used to evaluate the safety and efficacy of medical treatments, interventions, or procedures.

In a typical follow-up study, a group of individuals (called a cohort) who have received a particular treatment or intervention are identified and then followed over time through periodic assessments or data collection. The data collected may include information on clinical outcomes, adverse events, changes in symptoms or functional status, and other relevant measures.

The results of follow-up studies can provide important insights into the long-term benefits and risks of medical interventions, as well as help to identify factors that may influence treatment effectiveness or patient outcomes. However, it is important to note that follow-up studies can be subject to various biases and limitations, such as loss to follow-up, recall bias, and changes in clinical practice over time, which must be carefully considered when interpreting the results.

Physical exertion is defined as the act of applying energy to physically demandable activities or tasks, which results in various body systems working together to produce movement and maintain homeostasis. It often leads to an increase in heart rate, respiratory rate, and body temperature, among other physiological responses. The level of physical exertion can vary based on the intensity, duration, and frequency of the activity.

It's important to note that engaging in regular physical exertion has numerous health benefits, such as improving cardiovascular fitness, strengthening muscles and bones, reducing stress, and preventing chronic diseases like obesity, diabetes, and heart disease. However, it is also crucial to balance physical exertion with adequate rest and recovery time to avoid overtraining or injury.

Vasodilation is the widening or increase in diameter of blood vessels, particularly the involuntary relaxation of the smooth muscle in the tunica media (middle layer) of the arteriole walls. This results in an increase in blood flow and a decrease in vascular resistance. Vasodilation can occur due to various physiological and pathophysiological stimuli, such as local metabolic demands, neural signals, or pharmacological agents. It plays a crucial role in regulating blood pressure, tissue perfusion, and thermoregulation.

Denervation is a medical term that refers to the loss or removal of nerve supply to an organ or body part. This can occur as a result of surgical intervention, injury, or disease processes that damage the nerves leading to the affected area. The consequences of denervation depend on the specific organ or tissue involved, but generally, it can lead to changes in function, sensation, and muscle tone. For example, denervation of a skeletal muscle can cause weakness, atrophy, and altered reflexes. Similarly, denervation of an organ such as the heart can lead to abnormalities in heart rate and rhythm. In some cases, denervation may be intentional, such as during surgical procedures aimed at treating chronic pain or spasticity.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

Organ dysfunction scores are measurement tools used in critical care medicine to assess and quantify the degree of physiological derangement or failure in multiple organ systems. These scoring systems are designed to evaluate the overall severity of illness in critically ill patients, providing a standardized method for comparing patient outcomes and evaluating the effectiveness of different treatments.

There are several commonly used organ dysfunction scores, including:

1. Sequential Organ Failure Assessment (SOFA) score: This score assesses six organ systems (respiratory, cardiovascular, hepatic, coagulation, renal, and neurologic) on a scale of 0 to 4, with higher scores indicating more severe dysfunction or failure.
2. Multiple Organ Dysfunction Score (MODS): This score evaluates seven organ systems (respiratory, cardiovascular, hepatic, coagulation, renal, gastrointestinal, and neurologic) on a scale of 0 to 4, with higher scores indicating more severe dysfunction or failure.
3. Logistic Organ Dysfunction Score (LODS): This score assesses six organ systems (respiratory, cardiovascular, hepatic, coagulation, renal, and neurologic) on a scale of 0 to 100, with higher scores indicating more severe dysfunction or failure.
4. Acute Physiology And Chronic Health Evaluation II (APACHE II): While not strictly an organ dysfunction score, APACHE II includes components that assess organ dysfunction and is widely used in critical care settings to predict mortality risk.

These scores are typically calculated based on clinical data such as laboratory values, vital signs, and physiological measurements, and are often used to guide clinical decision-making, allocate resources, and compare outcomes across different patient populations or treatment strategies.

Diuresis is a medical term that refers to an increased production of urine by the kidneys. It can occur as a result of various factors, including certain medications, medical conditions, or as a response to a physiological need, such as in the case of dehydration. Diuretics are a class of drugs that promote diuresis and are often used to treat conditions such as high blood pressure, heart failure, and edema.

Diuresis can be classified into several types based on its underlying cause or mechanism, including:

1. Osmotic diuresis: This occurs when the kidneys excrete large amounts of urine in response to a high concentration of solutes (such as glucose) in the tubular fluid. The high osmolarity of the tubular fluid causes water to be drawn out of the bloodstream and into the urine, leading to an increase in urine output.
2. Forced diuresis: This is a medical procedure in which large amounts of intravenous fluids are administered to promote diuresis. It is used in certain clinical situations, such as to enhance the excretion of toxic substances or to prevent kidney damage.
3. Natriuretic diuresis: This occurs when the kidneys excrete large amounts of sodium and water in response to the release of natriuretic peptides, which are hormones that regulate sodium balance and blood pressure.
4. Aquaresis: This is a type of diuresis that occurs in response to the ingestion of large amounts of water, leading to dilute urine production.
5. Pathological diuresis: This refers to increased urine production due to underlying medical conditions such as diabetes insipidus or pyelonephritis.

It is important to note that excessive diuresis can lead to dehydration and electrolyte imbalances, so it should be monitored carefully in clinical settings.

The aorta is the largest artery in the human body, which originates from the left ventricle of the heart and carries oxygenated blood to the rest of the body. It can be divided into several parts, including the ascending aorta, aortic arch, and descending aorta. The ascending aorta gives rise to the coronary arteries that supply blood to the heart muscle. The aortic arch gives rise to the brachiocephalic, left common carotid, and left subclavian arteries, which supply blood to the head, neck, and upper extremities. The descending aorta travels through the thorax and abdomen, giving rise to various intercostal, visceral, and renal arteries that supply blood to the chest wall, organs, and kidneys.

Phenylephrine is a medication that belongs to the class of drugs known as sympathomimetic amines. It primarily acts as an alpha-1 adrenergic receptor agonist, which means it stimulates these receptors, leading to vasoconstriction (constriction of blood vessels). This effect can be useful in various medical situations, such as:

1. Nasal decongestion: When applied topically in the nose, phenylephrine causes constriction of the blood vessels in the nasal passages, which helps to relieve congestion and swelling. It is often found in over-the-counter (OTC) cold and allergy products.
2. Ocular circulation: In ophthalmology, phenylephrine is used to dilate the pupils before eye examinations. The increased pressure from vasoconstriction helps to open up the pupil, allowing for a better view of the internal structures of the eye.
3. Hypotension management: In some cases, phenylephrine may be given intravenously to treat low blood pressure (hypotension) during medical procedures like spinal anesthesia or septic shock. The vasoconstriction helps to increase blood pressure and improve perfusion of vital organs.

It is essential to use phenylephrine as directed, as improper usage can lead to adverse effects such as increased heart rate, hypertension, arrhythmias, and rebound congestion (when used as a nasal decongestant). Always consult with a healthcare professional for appropriate guidance on using this medication.

The splenic vein is a large, thin-walled vein that carries oxygenated blood from the spleen and pancreas to the liver. It is formed by the union of several smaller veins that drain the upper part of the stomach, the pancreas, and the left side of the colon (splenic flexure). The splenic vein runs along the top border of the pancreas and merges with the superior mesenteric vein to form the portal vein. This venous system allows for the filtration and detoxification of blood by the liver before it is distributed to the rest of the body.

Cardiovascular deconditioning is a condition that results from a decrease in the body's ability to adapt to physical stress due to a lack of regular physical activity and exercise. This leads to changes in the cardiovascular system, including reduced blood volume, stroke volume, and maximal oxygen uptake (VO2 max), as well as increased heart rate and systolic blood pressure during exercise.

Physical deconditioning can occur in individuals who are bedridden, sedentary, or have undergone prolonged periods of inactivity due to illness, injury, or other factors. It is also a concern for astronauts who experience reduced physical activity and muscle atrophy during spaceflight.

Cardiovascular deconditioning can lead to decreased exercise tolerance, fatigue, shortness of breath, and an increased risk of cardiovascular disease. Regular exercise and physical activity are essential for maintaining cardiovascular fitness and preventing deconditioning.

The heart ventricles are the two lower chambers of the heart that receive blood from the atria and pump it to the lungs or the rest of the body. The right ventricle pumps deoxygenated blood to the lungs, while the left ventricle pumps oxygenated blood to the rest of the body. Both ventricles have thick, muscular walls to generate the pressure necessary to pump blood through the circulatory system.

"Cat" is a common name that refers to various species of small carnivorous mammals that belong to the family Felidae. The domestic cat, also known as Felis catus or Felis silvestris catus, is a popular pet and companion animal. It is a subspecies of the wildcat, which is found in Europe, Africa, and Asia.

Domestic cats are often kept as pets because of their companionship, playful behavior, and ability to hunt vermin. They are also valued for their ability to provide emotional support and therapy to people. Cats are obligate carnivores, which means that they require a diet that consists mainly of meat to meet their nutritional needs.

Cats are known for their agility, sharp senses, and predatory instincts. They have retractable claws, which they use for hunting and self-defense. Cats also have a keen sense of smell, hearing, and vision, which allow them to detect prey and navigate their environment.

In medical terms, cats can be hosts to various parasites and diseases that can affect humans and other animals. Some common feline diseases include rabies, feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), and toxoplasmosis. It is important for cat owners to keep their pets healthy and up-to-date on vaccinations and preventative treatments to protect both the cats and their human companions.

Pulmonary hypertension is a medical condition characterized by increased blood pressure in the pulmonary arteries, which are the blood vessels that carry blood from the right side of the heart to the lungs. This results in higher than normal pressures in the pulmonary circulation and can lead to various symptoms and complications.

Pulmonary hypertension is typically defined as a mean pulmonary artery pressure (mPAP) greater than or equal to 25 mmHg at rest, as measured by right heart catheterization. The World Health Organization (WHO) classifies pulmonary hypertension into five groups based on the underlying cause:

1. Pulmonary arterial hypertension (PAH): This group includes idiopathic PAH, heritable PAH, drug-induced PAH, and associated PAH due to conditions such as connective tissue diseases, HIV infection, portal hypertension, congenital heart disease, and schistosomiasis.
2. Pulmonary hypertension due to left heart disease: This group includes conditions that cause elevated left atrial pressure, such as left ventricular systolic or diastolic dysfunction, valvular heart disease, and congenital cardiovascular shunts.
3. Pulmonary hypertension due to lung diseases and/or hypoxia: This group includes chronic obstructive pulmonary disease (COPD), interstitial lung disease, sleep-disordered breathing, alveolar hypoventilation disorders, and high altitude exposure.
4. Chronic thromboembolic pulmonary hypertension (CTEPH): This group includes persistent obstruction of the pulmonary arteries due to organized thrombi or emboli.
5. Pulmonary hypertension with unclear and/or multifactorial mechanisms: This group includes hematologic disorders, systemic disorders, metabolic disorders, and other conditions that can cause pulmonary hypertension but do not fit into the previous groups.

Symptoms of pulmonary hypertension may include shortness of breath, fatigue, chest pain, lightheadedness, and syncope (fainting). Diagnosis typically involves a combination of medical history, physical examination, imaging studies, and invasive testing such as right heart catheterization. Treatment depends on the underlying cause but may include medications, oxygen therapy, pulmonary rehabilitation, and, in some cases, surgical intervention.

Fluorophotometry is a medical diagnostic technique that measures the concentration of fluorescein dye in various tissues, particularly the eye. This technique utilizes a specialized instrument called a fluorophotometer which emits light at a specific wavelength that causes the fluorescein to emit light at a longer wavelength. The intensity of this emitted light is then measured and used to calculate the concentration of fluorescein in the tissue.

Fluorophotometry is often used in ophthalmology to assess the permeability of the blood-retinal barrier, which can be helpful in diagnosing and monitoring conditions such as diabetic retinopathy, age-related macular degeneration, and uveitis. It may also have applications in other medical fields for measuring the concentration of fluorescent markers in various tissues.

Right Ventricular Function refers to the ability of the right ventricle (RV) of the heart to receive and eject blood during the cardiac cycle. The right ventricle is one of the four chambers of the heart and is responsible for pumping deoxygenated blood from the body to the lungs for re-oxygenation.

Right ventricular function can be assessed by measuring various parameters such as:

1. Right Ventricular Ejection Fraction (RVEF): It is the percentage of blood that is ejected from the right ventricle during each heartbeat. A normal RVEF ranges from 45-75%.
2. Right Ventricular Systolic Function: It refers to the ability of the right ventricle to contract and eject blood during systole (contraction phase). This can be assessed by measuring the tricuspid annular plane systolic excursion (TAPSE) or tissue Doppler imaging.
3. Right Ventricular Diastolic Function: It refers to the ability of the right ventricle to relax and fill with blood during diastole (relaxation phase). This can be assessed by measuring the right ventricular inflow pattern, tricuspid valve E/A ratio, or deceleration time.
4. Right Ventricular Afterload: It refers to the pressure that the right ventricle must overcome to eject blood into the pulmonary artery. Increased afterload can impair right ventricular function.

Abnormalities in right ventricular function can lead to various cardiovascular conditions such as pulmonary hypertension, heart failure, and arrhythmias.

Stroke volume is a term used in cardiovascular physiology and medicine. It refers to the amount of blood that is pumped out of the left ventricle of the heart during each contraction (systole). Specifically, it is the difference between the volume of blood in the left ventricle at the end of diastole (when the ventricle is filled with blood) and the volume at the end of systole (when the ventricle has contracted and ejected its contents into the aorta).

Stroke volume is an important measure of heart function, as it reflects the ability of the heart to pump blood effectively to the rest of the body. A low stroke volume may indicate that the heart is not pumping efficiently, while a high stroke volume may suggest that the heart is working too hard. Stroke volume can be affected by various factors, including heart disease, high blood pressure, and physical fitness level.

The formula for calculating stroke volume is:

Stroke Volume = End-Diastolic Volume - End-Systolic Volume

Where end-diastolic volume (EDV) is the volume of blood in the left ventricle at the end of diastole, and end-systolic volume (ESV) is the volume of blood in the left ventricle at the end of systole.

The hepatic artery is a branch of the celiac trunk or abdominal aorta that supplies oxygenated blood to the liver. It typically divides into two main branches, the right and left hepatic arteries, which further divide into smaller vessels to supply different regions of the liver. The hepatic artery also gives off branches to supply other organs such as the gallbladder, pancreas, and duodenum.

It's worth noting that there is significant variability in the anatomy of the hepatic artery, with some individuals having additional branches or variations in the origin of the vessel. This variability can have implications for surgical procedures involving the liver and surrounding organs.

A chronic disease is a long-term medical condition that often progresses slowly over a period of years and requires ongoing management and care. These diseases are typically not fully curable, but symptoms can be managed to improve quality of life. Common chronic diseases include heart disease, stroke, cancer, diabetes, arthritis, and COPD (chronic obstructive pulmonary disease). They are often associated with advanced age, although they can also affect children and younger adults. Chronic diseases can have significant impacts on individuals' physical, emotional, and social well-being, as well as on healthcare systems and society at large.

Left ventricular function refers to the ability of the left ventricle (the heart's lower-left chamber) to contract and relax, thereby filling with and ejecting blood. The left ventricle is responsible for pumping oxygenated blood to the rest of the body. Its function is evaluated by measuring several parameters, including:

1. Ejection fraction (EF): This is the percentage of blood that is pumped out of the left ventricle with each heartbeat. A normal ejection fraction ranges from 55% to 70%.
2. Stroke volume (SV): The amount of blood pumped by the left ventricle in one contraction. A typical SV is about 70 mL/beat.
3. Cardiac output (CO): The total volume of blood that the left ventricle pumps per minute, calculated as the product of stroke volume and heart rate. Normal CO ranges from 4 to 8 L/minute.

Assessment of left ventricular function is crucial in diagnosing and monitoring various cardiovascular conditions such as heart failure, coronary artery disease, valvular heart diseases, and cardiomyopathies.

Adrenergic beta-antagonists, also known as beta blockers, are a class of medications that block the effects of adrenaline and noradrenaline (also known as epinephrine and norepinephrine) on beta-adrenergic receptors. These receptors are found in various tissues throughout the body, including the heart, lungs, and blood vessels.

Beta blockers work by binding to these receptors and preventing the activation of certain signaling pathways that lead to increased heart rate, force of heart contractions, and relaxation of blood vessels. As a result, beta blockers can lower blood pressure, reduce heart rate, and decrease the workload on the heart.

Beta blockers are used to treat a variety of medical conditions, including hypertension (high blood pressure), angina (chest pain), heart failure, irregular heart rhythms, migraines, and certain anxiety disorders. Some common examples of beta blockers include metoprolol, atenolol, propranolol, and bisoprolol.

It is important to note that while beta blockers can have many benefits, they can also cause side effects such as fatigue, dizziness, and shortness of breath. Additionally, sudden discontinuation of beta blocker therapy can lead to rebound hypertension or worsening chest pain. Therefore, it is important to follow the dosing instructions provided by a healthcare provider carefully when taking these medications.

Superior Vena Cava Syndrome (SVCS) is a medical condition characterized by the obstruction of the superior vena cava (SVC), which is the large vein that carries blood from the upper body to the heart. This obstruction can be caused by cancerous tumors, thrombosis (blood clots), or other compressive factors.

The obstruction results in the impaired flow of blood from the head, neck, arms, and upper chest, leading to a variety of symptoms such as swelling of the face, neck, and upper extremities; shortness of breath; cough; chest pain; and distended veins visible on the skin surface. In severe cases, SVCS can cause life-threatening complications like cerebral edema (swelling of the brain) or pulmonary edema (fluid accumulation in the lungs).

Immediate medical attention is required for individuals with suspected SVCS to prevent further complications and to manage the underlying cause. Treatment options may include chemotherapy, radiation therapy, anticoagulation therapy, or surgery, depending on the etiology of the obstruction.

Septic shock is a serious condition that occurs as a complication of an infection that has spread throughout the body. It's characterized by a severe drop in blood pressure and abnormalities in cellular metabolism, which can lead to organ failure and death if not promptly treated.

In septic shock, the immune system overreacts to an infection, releasing an overwhelming amount of inflammatory chemicals into the bloodstream. This leads to widespread inflammation, blood vessel dilation, and leaky blood vessels, which can cause fluid to leak out of the blood vessels and into surrounding tissues. As a result, the heart may not be able to pump enough blood to vital organs, leading to organ failure.

Septic shock is often caused by bacterial infections, but it can also be caused by fungal or viral infections. It's most commonly seen in people with weakened immune systems, such as those who have recently undergone surgery, have chronic medical conditions, or are taking medications that suppress the immune system.

Prompt diagnosis and treatment of septic shock is critical to prevent long-term complications and improve outcomes. Treatment typically involves aggressive antibiotic therapy, intravenous fluids, vasopressors to maintain blood pressure, and supportive care in an intensive care unit (ICU).

Nonparametric statistics is a branch of statistics that does not rely on assumptions about the distribution of variables in the population from which the sample is drawn. In contrast to parametric methods, nonparametric techniques make fewer assumptions about the data and are therefore more flexible in their application. Nonparametric tests are often used when the data do not meet the assumptions required for parametric tests, such as normality or equal variances.

Nonparametric statistical methods include tests such as the Wilcoxon rank-sum test (also known as the Mann-Whitney U test) for comparing two independent groups, the Wilcoxon signed-rank test for comparing two related groups, and the Kruskal-Wallis test for comparing more than two independent groups. These tests use the ranks of the data rather than the actual values to make comparisons, which allows them to be used with ordinal or continuous data that do not meet the assumptions of parametric tests.

Overall, nonparametric statistics provide a useful set of tools for analyzing data in situations where the assumptions of parametric methods are not met, and can help researchers draw valid conclusions from their data even when the data are not normally distributed or have other characteristics that violate the assumptions of parametric tests.

The femoral artery is the major blood vessel that supplies oxygenated blood to the lower extremity of the human body. It is a continuation of the external iliac artery and becomes the popliteal artery as it passes through the adductor hiatus in the adductor magnus muscle of the thigh.

The femoral artery is located in the femoral triangle, which is bound by the sartorius muscle anteriorly, the adductor longus muscle medially, and the biceps femoris muscle posteriorly. It can be easily palpated in the groin region, making it a common site for taking blood samples, measuring blood pressure, and performing surgical procedures such as femoral artery catheterization and bypass grafting.

The femoral artery gives off several branches that supply blood to the lower limb, including the deep femoral artery, the superficial femoral artery, and the profunda femoris artery. These branches provide blood to the muscles, bones, skin, and other tissues of the leg, ankle, and foot.

Edema is the medical term for swelling caused by excess fluid accumulation in the body tissues. It can affect any part of the body, but it's most commonly noticed in the hands, feet, ankles, and legs. Edema can be a symptom of various underlying medical conditions, such as heart failure, kidney disease, liver disease, or venous insufficiency.

The swelling occurs when the capillaries leak fluid into the surrounding tissues, causing them to become swollen and puffy. The excess fluid can also collect in the cavities of the body, leading to conditions such as pleural effusion (fluid around the lungs) or ascites (fluid in the abdominal cavity).

The severity of edema can vary from mild to severe, and it may be accompanied by other symptoms such as skin discoloration, stiffness, and pain. Treatment for edema depends on the underlying cause and may include medications, lifestyle changes, or medical procedures.

Cardiac surgical procedures are operations that are performed on the heart or great vessels (the aorta and vena cava) by cardiothoracic surgeons. These surgeries are often complex and require a high level of skill and expertise. Some common reasons for cardiac surgical procedures include:

1. Coronary artery bypass grafting (CABG): This is a surgery to improve blood flow to the heart in patients with coronary artery disease. During the procedure, a healthy blood vessel from another part of the body is used to create a detour around the blocked or narrowed portion of the coronary artery.
2. Valve repair or replacement: The heart has four valves that control blood flow through and out of the heart. If one or more of these valves become damaged or diseased, they may need to be repaired or replaced. This can be done using artificial valves or valves from animal or human donors.
3. Aneurysm repair: An aneurysm is a weakened area in the wall of an artery that can bulge out and potentially rupture. If an aneurysm occurs in the aorta, it may require surgical repair to prevent rupture.
4. Heart transplantation: In some cases, heart failure may be so severe that a heart transplant is necessary. This involves removing the diseased heart and replacing it with a healthy donor heart.
5. Arrhythmia surgery: Certain types of abnormal heart rhythms (arrhythmias) may require surgical treatment. One such procedure is called the Maze procedure, which involves creating a pattern of scar tissue in the heart to disrupt the abnormal electrical signals that cause the arrhythmia.
6. Congenital heart defect repair: Some people are born with structural problems in their hearts that require surgical correction. These may include holes between the chambers of the heart or abnormal blood vessels.

Cardiac surgical procedures carry risks, including bleeding, infection, stroke, and death. However, for many patients, these surgeries can significantly improve their quality of life and longevity.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.

Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.

Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.

Intensive care is a specialized level of medical care that is provided to critically ill patients. It's usually given in a dedicated unit of a hospital called the Intensive Care Unit (ICU) or Critical Care Unit (CCU). The goal of intensive care is to closely monitor and manage life-threatening conditions, stabilize vital functions, and support organs until they recover or the patient can be moved to a less acute level of care.

Intensive care involves advanced medical equipment and technologies, such as ventilators to assist with breathing, dialysis machines for kidney support, intravenous lines for medication administration, and continuous monitoring devices for heart rate, blood pressure, oxygen levels, and other vital signs.

The ICU team typically includes intensive care specialists (intensivists), critical care nurses, respiratory therapists, and other healthcare professionals who work together to provide comprehensive, round-the-clock care for critically ill patients.

Angiotensin II is a potent vasoactive peptide hormone that plays a critical role in the renin-angiotensin-aldosterone system (RAAS), which is a crucial regulator of blood pressure and fluid balance in the body. It is formed from angiotensin I through the action of an enzyme called angiotensin-converting enzyme (ACE).

Angiotensin II has several physiological effects on various organs, including:

1. Vasoconstriction: Angiotensin II causes contraction of vascular smooth muscle, leading to an increase in peripheral vascular resistance and blood pressure.
2. Aldosterone release: Angiotensin II stimulates the adrenal glands to release aldosterone, a hormone that promotes sodium reabsorption and potassium excretion in the kidneys, thereby increasing water retention and blood volume.
3. Sympathetic nervous system activation: Angiotensin II activates the sympathetic nervous system, leading to increased heart rate and contractility, further contributing to an increase in blood pressure.
4. Thirst regulation: Angiotensin II stimulates the hypothalamus to increase thirst, promoting water intake and helping to maintain intravascular volume.
5. Cell growth and fibrosis: Angiotensin II has been implicated in various pathological processes, such as cell growth, proliferation, and fibrosis, which can contribute to the development of cardiovascular and renal diseases.

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are two classes of medications commonly used in clinical practice to target the RAAS by blocking the formation or action of angiotensin II, respectively. These drugs have been shown to be effective in managing hypertension, heart failure, and chronic kidney disease.

A vagotomy is a surgical procedure that involves cutting or blocking the vagus nerve, which is a parasympathetic nerve that runs from the brainstem to the abdomen and helps regulate many bodily functions such as heart rate, gastrointestinal motility, and digestion. In particular, vagotomy is often performed as a treatment for peptic ulcers, as it can help reduce gastric acid secretion.

There are several types of vagotomy procedures, including:

1. Truncal vagotomy: This involves cutting the main trunks of the vagus nerve as they enter the abdomen. It is a more extensive procedure that reduces gastric acid secretion significantly but can also lead to side effects such as delayed gastric emptying and diarrhea.
2. Selective vagotomy: This involves cutting only the branches of the vagus nerve that supply the stomach, leaving the rest of the nerve intact. It is a less extensive procedure that reduces gastric acid secretion while minimizing side effects.
3. Highly selective vagotomy (HSV): Also known as parietal cell vagotomy, this involves cutting only the branches of the vagus nerve that supply the acid-secreting cells in the stomach. It is a highly targeted procedure that reduces gastric acid secretion while minimizing side effects such as delayed gastric emptying and diarrhea.

Vagotomy is typically performed using laparoscopic or open surgical techniques, depending on the patient's individual needs and the surgeon's preference. While vagotomy can be effective in treating peptic ulcers, it is not commonly performed today due to the development of less invasive treatments such as proton pump inhibitors (PPIs) that reduce gastric acid secretion without surgery.

A lung is a pair of spongy, elastic organs in the chest that work together to enable breathing. They are responsible for taking in oxygen and expelling carbon dioxide through the process of respiration. The left lung has two lobes, while the right lung has three lobes. The lungs are protected by the ribcage and are covered by a double-layered membrane called the pleura. The trachea divides into two bronchi, which further divide into smaller bronchioles, leading to millions of tiny air sacs called alveoli, where the exchange of gases occurs.

Phlebography is a medical imaging technique used to visualize and assess the veins, particularly in the legs. It involves the injection of a contrast agent into the veins, followed by X-ray imaging to capture the flow of the contrast material through the veins. This allows doctors to identify any abnormalities such as blood clots, blockages, or malformations in the venous system.

There are different types of phlebography, including ascending phlebography (where the contrast agent is injected into a foot vein and travels up the leg) and descending phlebography (where the contrast agent is injected into a vein in the groin or neck and travels down the leg).

Phlebography is an invasive procedure that requires careful preparation and monitoring, and it is typically performed by radiologists or vascular specialists. It has largely been replaced by non-invasive imaging techniques such as ultrasound and CT angiography in many clinical settings.

Retrospective studies, also known as retrospective research or looking back studies, are a type of observational study that examines data from the past to draw conclusions about possible causal relationships between risk factors and outcomes. In these studies, researchers analyze existing records, medical charts, or previously collected data to test a hypothesis or answer a specific research question.

Retrospective studies can be useful for generating hypotheses and identifying trends, but they have limitations compared to prospective studies, which follow participants forward in time from exposure to outcome. Retrospective studies are subject to biases such as recall bias, selection bias, and information bias, which can affect the validity of the results. Therefore, retrospective studies should be interpreted with caution and used primarily to generate hypotheses for further testing in prospective studies.

Resuscitation is a medical term that refers to the process of reversing cardiopulmonary arrest or preventing further deterioration of someone in cardiac or respiratory arrest. It involves a series of interventions aimed at restoring spontaneous blood circulation and breathing, thereby preventing or minimizing tissue damage due to lack of oxygen.

The most common form of resuscitation is cardiopulmonary resuscitation (CPR), which combines chest compressions to manually pump blood through the body with rescue breaths to provide oxygen to the lungs. In a hospital setting, more advanced techniques such as defibrillation, medication administration, and intubation may also be used as part of the resuscitation process.

The goal of resuscitation is to stabilize the patient's condition and prevent further harm while treating the underlying cause of the arrest. Successful resuscitation can lead to a full recovery or, in some cases, result in varying degrees of neurological impairment depending on the severity and duration of the cardiac or respiratory arrest.

Echocardiography is a medical procedure that uses sound waves to produce detailed images of the heart's structure, function, and motion. It is a non-invasive test that can help diagnose various heart conditions, such as valve problems, heart muscle damage, blood clots, and congenital heart defects.

During an echocardiogram, a transducer (a device that sends and receives sound waves) is placed on the chest or passed through the esophagus to obtain images of the heart. The sound waves produced by the transducer bounce off the heart structures and return to the transducer, which then converts them into electrical signals that are processed to create images of the heart.

There are several types of echocardiograms, including:

* Transthoracic echocardiography (TTE): This is the most common type of echocardiogram and involves placing the transducer on the chest.
* Transesophageal echocardiography (TEE): This type of echocardiogram involves passing a specialized transducer through the esophagus to obtain images of the heart from a closer proximity.
* Stress echocardiography: This type of echocardiogram is performed during exercise or medication-induced stress to assess how the heart functions under stress.
* Doppler echocardiography: This type of echocardiogram uses sound waves to measure blood flow and velocity in the heart and blood vessels.

Echocardiography is a valuable tool for diagnosing and managing various heart conditions, as it provides detailed information about the structure and function of the heart. It is generally safe, non-invasive, and painless, making it a popular choice for doctors and patients alike.

Isosorbide dinitrate is a medication that belongs to a class of drugs called nitrates. It is primarily used in the prevention and treatment of angina pectoris, which is chest pain caused by reduced blood flow to the heart muscle.

The medical definition of Isosorbide dinitrate is:

A soluble nitrate ester used in the prevention and treatment of anginal attacks. It acts by dilating coronary and peripheral arteries and veins, thereby reducing cardiac workload and increasing oxygen delivery to the heart muscle. Its therapeutic effects are attributed to its conversion to nitric oxide, a potent vasodilator, in the body. Isosorbide dinitrate is available in various forms, including tablets, capsules, and oral solutions, and is typically taken 2-3 times daily for optimal effect.

Pulmonary veins are blood vessels that carry oxygenated blood from the lungs to the left atrium of the heart. There are four pulmonary veins in total, two from each lung, and they are the only veins in the body that carry oxygen-rich blood. The oxygenated blood from the pulmonary veins is then pumped by the left ventricle to the rest of the body through the aorta. Any blockage or damage to the pulmonary veins can lead to various cardiopulmonary conditions, such as pulmonary hypertension and congestive heart failure.

Electrocardiography (ECG or EKG) is a medical procedure that records the electrical activity of the heart. It provides a graphic representation of the electrical changes that occur during each heartbeat. The resulting tracing, called an electrocardiogram, can reveal information about the heart's rate and rhythm, as well as any damage to its cells or abnormalities in its conduction system.

During an ECG, small electrodes are placed on the skin of the chest, arms, and legs. These electrodes detect the electrical signals produced by the heart and transmit them to a machine that amplifies and records them. The procedure is non-invasive, painless, and quick, usually taking only a few minutes.

ECGs are commonly used to diagnose and monitor various heart conditions, including arrhythmias, coronary artery disease, heart attacks, and electrolyte imbalances. They can also be used to evaluate the effectiveness of certain medications or treatments.

Reproducibility of results in a medical context refers to the ability to obtain consistent and comparable findings when a particular experiment or study is repeated, either by the same researcher or by different researchers, following the same experimental protocol. It is an essential principle in scientific research that helps to ensure the validity and reliability of research findings.

In medical research, reproducibility of results is crucial for establishing the effectiveness and safety of new treatments, interventions, or diagnostic tools. It involves conducting well-designed studies with adequate sample sizes, appropriate statistical analyses, and transparent reporting of methods and findings to allow other researchers to replicate the study and confirm or refute the results.

The lack of reproducibility in medical research has become a significant concern in recent years, as several high-profile studies have failed to produce consistent findings when replicated by other researchers. This has led to increased scrutiny of research practices and a call for greater transparency, rigor, and standardization in the conduct and reporting of medical research.

The Predictive Value of Tests, specifically the Positive Predictive Value (PPV) and Negative Predictive Value (NPV), are measures used in diagnostic tests to determine the probability that a positive or negative test result is correct.

Positive Predictive Value (PPV) is the proportion of patients with a positive test result who actually have the disease. It is calculated as the number of true positives divided by the total number of positive results (true positives + false positives). A higher PPV indicates that a positive test result is more likely to be a true positive, and therefore the disease is more likely to be present.

Negative Predictive Value (NPV) is the proportion of patients with a negative test result who do not have the disease. It is calculated as the number of true negatives divided by the total number of negative results (true negatives + false negatives). A higher NPV indicates that a negative test result is more likely to be a true negative, and therefore the disease is less likely to be present.

The predictive value of tests depends on the prevalence of the disease in the population being tested, as well as the sensitivity and specificity of the test. A test with high sensitivity and specificity will generally have higher predictive values than a test with low sensitivity and specificity. However, even a highly sensitive and specific test can have low predictive values if the prevalence of the disease is low in the population being tested.

The double-blind method is a study design commonly used in research, including clinical trials, to minimize bias and ensure the objectivity of results. In this approach, both the participants and the researchers are unaware of which group the participants are assigned to, whether it be the experimental group or the control group. This means that neither the participants nor the researchers know who is receiving a particular treatment or placebo, thus reducing the potential for bias in the evaluation of outcomes. The assignment of participants to groups is typically done by a third party not involved in the study, and the codes are only revealed after all data have been collected and analyzed.

A Severity of Illness Index is a measurement tool used in healthcare to assess the severity of a patient's condition and the risk of mortality or other adverse outcomes. These indices typically take into account various physiological and clinical variables, such as vital signs, laboratory values, and co-morbidities, to generate a score that reflects the patient's overall illness severity.

Examples of Severity of Illness Indices include the Acute Physiology and Chronic Health Evaluation (APACHE) system, the Simplified Acute Physiology Score (SAPS), and the Mortality Probability Model (MPM). These indices are often used in critical care settings to guide clinical decision-making, inform prognosis, and compare outcomes across different patient populations.

It is important to note that while these indices can provide valuable information about a patient's condition, they should not be used as the sole basis for clinical decision-making. Rather, they should be considered in conjunction with other factors, such as the patient's overall clinical presentation, treatment preferences, and goals of care.

Acid-base equilibrium refers to the balance between the concentration of acids and bases in a solution, which determines its pH level. In a healthy human body, maintaining acid-base equilibrium is crucial for proper cellular function and homeostasis.

The balance is maintained by several buffering systems in the body, including the bicarbonate buffer system, which helps to regulate the pH of blood. This system involves the reaction between carbonic acid (a weak acid) and bicarbonate ions (a base) to form water and carbon dioxide.

The balance between acids and bases is carefully regulated by the body's respiratory and renal systems. The lungs control the elimination of carbon dioxide, a weak acid, through exhalation, while the kidneys regulate the excretion of hydrogen ions and the reabsorption of bicarbonate ions.

When the balance between acids and bases is disrupted, it can lead to acid-base disorders such as acidosis (excessive acidity) or alkalosis (excessive basicity). These conditions can have serious consequences on various organ systems if left untreated.

SHR (Spontaneously Hypertensive Rats) are an inbred strain of rats that were originally developed through selective breeding for high blood pressure. They are widely used as a model to study hypertension and related cardiovascular diseases, as well as neurological disorders such as stroke and dementia.

Inbred strains of animals are created by mating genetically identical individuals (siblings or offspring) for many generations, resulting in a population that is highly homozygous at all genetic loci. This means that the animals within an inbred strain are essentially genetically identical to one another, which makes them useful for studying the effects of specific genes or environmental factors on disease processes.

SHR rats develop high blood pressure spontaneously, without any experimental manipulation, and show many features of human hypertension, such as increased vascular resistance, left ventricular hypertrophy, and renal dysfunction. They also exhibit a number of behavioral abnormalities, including hyperactivity, impulsivity, and cognitive deficits, which make them useful for studying the neurological consequences of hypertension and other cardiovascular diseases.

Overall, inbred SHR rats are an important tool in biomedical research, providing a valuable model for understanding the genetic and environmental factors that contribute to hypertension and related disorders.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

The postoperative period is the time following a surgical procedure during which the patient's response to the surgery and anesthesia is monitored, and any complications or adverse effects are managed. This period can vary in length depending on the type of surgery and the individual patient's needs, but it typically includes the immediate recovery phase in the post-anesthesia care unit (PACU) or recovery room, as well as any additional time spent in the hospital for monitoring and management of pain, wound healing, and other aspects of postoperative care.

The goals of postoperative care are to ensure the patient's safety and comfort, promote optimal healing and rehabilitation, and minimize the risk of complications such as infection, bleeding, or other postoperative issues. The specific interventions and treatments provided during this period will depend on a variety of factors, including the type and extent of surgery performed, the patient's overall health and medical history, and any individualized care plans developed in consultation with the patient and their healthcare team.

The mesenteric veins are a set of blood vessels that are responsible for draining deoxygenated blood from the small and large intestines. There are two main mesenteric veins: the superior mesenteric vein and the inferior mesenteric vein. The superior mesenteric vein drains blood from the majority of the small intestine, as well as the ascending colon and proximal two-thirds of the transverse colon. The inferior mesenteric vein drains blood from the distal third of the transverse colon, descending colon, sigmoid colon, and rectum. These veins ultimately drain into the portal vein, which carries the blood to the liver for further processing.

I apologize, but "sheep" is not a term that has a medical definition. It is a common animal with the scientific name Ovis aries. If you have any medical or health-related questions, I would be happy to try and help answer those for you.

Ventricular function, in the context of cardiac medicine, refers to the ability of the heart's ventricles (the lower chambers) to fill with blood during the diastole phase and eject blood during the systole phase. The ventricles are primarily responsible for pumping oxygenated blood out to the body (left ventricle) and deoxygenated blood to the lungs (right ventricle).

There are several ways to assess ventricular function, including:

1. Ejection Fraction (EF): This is the most commonly used measure of ventricular function. It represents the percentage of blood that is ejected from the ventricle during each heartbeat. A normal left ventricular ejection fraction is typically between 55% and 70%.
2. Fractional Shortening (FS): This is another measure of ventricular function, which calculates the change in size of the ventricle during contraction as a percentage of the original size. A normal FS for the left ventricle is typically between 25% and 45%.
3. Stroke Volume (SV): This refers to the amount of blood that is pumped out of the ventricle with each heartbeat. SV is calculated by multiplying the ejection fraction by the end-diastolic volume (the amount of blood in the ventricle at the end of diastole).
4. Cardiac Output (CO): This is the total amount of blood that the heart pumps in one minute. It is calculated by multiplying the stroke volume by the heart rate.

Impaired ventricular function can lead to various cardiovascular conditions, such as heart failure, cardiomyopathy, and valvular heart disease. Assessing ventricular function is crucial for diagnosing these conditions, monitoring treatment response, and guiding clinical decision-making.

I'm sorry for any confusion, but "Linear Models" is actually a term from the field of statistics and machine learning, rather than medicine. A linear model is a type of statistical model that is used to analyze the relationship between two or more variables. In a linear model, the relationship between the dependent variable (the outcome or result) and the independent variable(s) (the factors being studied) is assumed to be linear, meaning that it can be described by a straight line on a graph.

The equation for a simple linear model with one independent variable (x) and one dependent variable (y) looks like this:

y = β0 + β1*x + ε

In this equation, β0 is the y-intercept or the value of y when x equals zero, β1 is the slope or the change in y for each unit increase in x, and ε is the error term or the difference between the actual values of y and the predicted values of y based on the linear model.

Linear models are widely used in medical research to study the relationship between various factors (such as exposure to a risk factor or treatment) and health outcomes (such as disease incidence or mortality). They can also be used to adjust for confounding variables, which are factors that may influence both the independent variable and the dependent variable, and thus affect the observed relationship between them.

Regression analysis is a statistical technique used in medicine, as well as in other fields, to examine the relationship between one or more independent variables (predictors) and a dependent variable (outcome). It allows for the estimation of the average change in the outcome variable associated with a one-unit change in an independent variable, while controlling for the effects of other independent variables. This technique is often used to identify risk factors for diseases or to evaluate the effectiveness of medical interventions. In medical research, regression analysis can be used to adjust for potential confounding variables and to quantify the relationship between exposures and health outcomes. It can also be used in predictive modeling to estimate the probability of a particular outcome based on multiple predictors.

The abdomen refers to the portion of the body that lies between the thorax (chest) and the pelvis. It is a musculo-fascial cavity containing the digestive, urinary, and reproductive organs. The abdominal cavity is divided into several regions and quadrants for medical description and examination purposes. These include the upper and lower abdomen, as well as nine quadrants formed by the intersection of the midline and a horizontal line drawn at the level of the umbilicus (navel).

The major organs located within the abdominal cavity include:

1. Stomach - muscular organ responsible for initial digestion of food
2. Small intestine - long, coiled tube where most nutrient absorption occurs
3. Large intestine - consists of the colon and rectum; absorbs water and stores waste products
4. Liver - largest internal organ, involved in protein synthesis, detoxification, and metabolism
5. Pancreas - secretes digestive enzymes and hormones such as insulin
6. Spleen - filters blood and removes old red blood cells
7. Kidneys - pair of organs responsible for filtering waste products from the blood and producing urine
8. Adrenal glands - sit atop each kidney, produce hormones that regulate metabolism, immune response, and stress response

The abdomen is an essential part of the human body, playing a crucial role in digestion, absorption, and elimination of food and waste materials, as well as various metabolic processes.

Filtration in the medical context refers to a process used in various medical treatments and procedures, where a substance is passed through a filter with the purpose of removing impurities or unwanted components. The filter can be made up of different materials such as paper, cloth, or synthetic membranes, and it works by trapping particles or molecules based on their size, shape, or charge.

For example, filtration is commonly used in kidney dialysis to remove waste products and excess fluids from the blood. In this case, the patient's blood is pumped through a special filter called a dialyzer, which separates waste products and excess fluids from the blood based on size differences between these substances and the blood cells. The clean blood is then returned to the patient's body.

Filtration is also used in other medical applications such as water purification, air filtration, and tissue engineering. In each case, the goal is to remove unwanted components or impurities from a substance, making it safer or more effective for use in medical treatments and procedures.

Surgical hemostasis refers to the methods and techniques used during surgical procedures to stop bleeding or prevent hemorrhage. This can be achieved through various means, including the use of surgical instruments such as clamps, ligatures, or staples to physically compress blood vessels and stop the flow of blood. Electrosurgical tools like cautery may also be used to coagulate and seal off bleeding vessels using heat. Additionally, topical hemostatic agents can be applied to promote clotting and control bleeding in wounded tissues. Effective surgical hemostasis is crucial for ensuring a successful surgical outcome and minimizing the risk of complications such as excessive blood loss, infection, or delayed healing.

Hemorrhage is defined in the medical context as an excessive loss of blood from the circulatory system, which can occur due to various reasons such as injury, surgery, or underlying health conditions that affect blood clotting or the integrity of blood vessels. The bleeding may be internal, external, visible, or concealed, and it can vary in severity from minor to life-threatening, depending on the location and extent of the bleeding. Hemorrhage is a serious medical emergency that requires immediate attention and treatment to prevent further blood loss, organ damage, and potential death.

"Swine" is a common term used to refer to even-toed ungulates of the family Suidae, including domestic pigs and wild boars. However, in a medical context, "swine" often appears in the phrase "swine flu," which is a strain of influenza virus that typically infects pigs but can also cause illness in humans. The 2009 H1N1 pandemic was caused by a new strain of swine-origin influenza A virus, which was commonly referred to as "swine flu." It's important to note that this virus is not transmitted through eating cooked pork products; it spreads from person to person, mainly through respiratory droplets produced when an infected person coughs or sneezes.

Intra-arterial injection is a type of medical procedure where a medication or contrast agent is delivered directly into an artery. This technique is used for various therapeutic and diagnostic purposes.

For instance, intra-arterial chemotherapy may be used to deliver cancer drugs directly to the site of a tumor, while intra-arterial thrombolysis involves the administration of clot-busting medications to treat arterial blockages caused by blood clots. Intra-arterial injections are also used in diagnostic imaging procedures such as angiography, where a contrast agent is injected into an artery to visualize the blood vessels and identify any abnormalities.

It's important to note that intra-arterial injections require precise placement of the needle or catheter into the artery, and are typically performed by trained medical professionals using specialized equipment.

Cranial sinuses are a part of the venous system in the human head. They are air-filled spaces located within the skull and are named according to their location. The cranial sinuses include:

1. Superior sagittal sinus: It runs along the top of the brain, inside the skull, and drains blood from the scalp and the veins of the brain.
2. Inferior sagittal sinus: It runs along the bottom of the brain and drains into the straight sinus.
3. Straight sinus: It is located at the back of the brain and receives blood from the inferior sagittal sinus and great cerebral vein.
4. Occipital sinuses: They are located at the back of the head and drain blood from the scalp and skull.
5. Cavernous sinuses: They are located on each side of the brain, near the temple, and receive blood from the eye and surrounding areas.
6. Sphenoparietal sinus: It is a small sinus that drains blood from the front part of the brain into the cavernous sinus.
7. Petrosquamosal sinuses: They are located near the ear and drain blood from the scalp and skull.

The cranial sinuses play an essential role in draining blood from the brain and protecting it from injury.

The intraoperative period is the phase of surgical treatment that refers to the time during which the surgery is being performed. It begins when the anesthesia is administered and the patient is prepared for the operation, and it ends when the surgery is completed, the anesthesia is discontinued, and the patient is transferred to the recovery room or intensive care unit (ICU).

During the intraoperative period, the surgical team, including surgeons, anesthesiologists, nurses, and other healthcare professionals, work together to carry out the surgical procedure safely and effectively. The anesthesiologist monitors the patient's vital signs, such as heart rate, blood pressure, oxygen saturation, and body temperature, throughout the surgery to ensure that the patient remains stable and does not experience any complications.

The surgeon performs the operation, using various surgical techniques and instruments to achieve the desired outcome. The surgical team also takes measures to prevent infection, control bleeding, and manage pain during and after the surgery.

Overall, the intraoperative period is a critical phase of surgical treatment that requires close collaboration and communication among members of the healthcare team to ensure the best possible outcomes for the patient.

Intravenous (IV) infusion is a medical procedure in which liquids, such as medications, nutrients, or fluids, are delivered directly into a patient's vein through a needle or a catheter. This route of administration allows for rapid absorption and distribution of the infused substance throughout the body. IV infusions can be used for various purposes, including resuscitation, hydration, nutrition support, medication delivery, and blood product transfusion. The rate and volume of the infusion are carefully controlled to ensure patient safety and efficacy of treatment.

The heart atria are the upper chambers of the heart that receive blood from the veins and deliver it to the lower chambers, or ventricles. There are two atria in the heart: the right atrium receives oxygen-poor blood from the body and pumps it into the right ventricle, which then sends it to the lungs to be oxygenated; and the left atrium receives oxygen-rich blood from the lungs and pumps it into the left ventricle, which then sends it out to the rest of the body. The atria contract before the ventricles during each heartbeat, helping to fill the ventricles with blood and prepare them for contraction.

Weightlessness simulation, also known as "zero-gravity" or "microgravity" simulation, is the reproduction of the condition in which people or objects appear to be weightless. This state can be achieved through various methods, including neutral buoyancy, which is simulating the feeling of weightlessness by immersing individuals in a fluid (usually water) with a density equal to their body, or reduced-gravity environments created using specialized equipment such as aircraft that fly in parabolic arcs to generate brief periods of weightlessness.

Another method for weightlessness simulation is through the use of virtual reality and other technology to create an illusion of weightlessness. This can be done by manipulating visual and auditory cues, as well as providing a haptic feedback system that simulates the sensation of movement in zero-gravity environments. These simulations are often used for training astronauts, researching the effects of weightlessness on the human body, and developing technologies for use in space.

Congenital heart defects (CHDs) are structural abnormalities in the heart that are present at birth. They can affect any part of the heart's structure, including the walls of the heart, the valves inside the heart, and the major blood vessels that lead to and from the heart.

Congenital heart defects can range from mild to severe and can cause various symptoms depending on the type and severity of the defect. Some common symptoms of CHDs include cyanosis (a bluish tint to the skin, lips, and fingernails), shortness of breath, fatigue, poor feeding, and slow growth in infants and children.

There are many different types of congenital heart defects, including:

1. Septal defects: These are holes in the walls that separate the four chambers of the heart. The two most common septal defects are atrial septal defect (ASD) and ventricular septal defect (VSD).
2. Valve abnormalities: These include narrowed or leaky valves, which can affect blood flow through the heart.
3. Obstruction defects: These occur when blood flow is blocked or restricted due to narrowing or absence of a part of the heart's structure. Examples include pulmonary stenosis and coarctation of the aorta.
4. Cyanotic heart defects: These cause a lack of oxygen in the blood, leading to cyanosis. Examples include tetralogy of Fallot and transposition of the great arteries.

The causes of congenital heart defects are not fully understood, but genetic factors and environmental influences during pregnancy may play a role. Some CHDs can be detected before birth through prenatal testing, while others may not be diagnosed until after birth or later in childhood. Treatment for CHDs may include medication, surgery, or other interventions to improve blood flow and oxygenation of the body's tissues.

Inhalational anesthesia is a type of general anesthesia that is induced by the inhalation of gases or vapors. It is administered through a breathing system, which delivers the anesthetic agents to the patient via a face mask, laryngeal mask airway, or endotracheal tube.

The most commonly used inhalational anesthetics include nitrous oxide, sevoflurane, isoflurane, and desflurane. These agents work by depressing the central nervous system, causing a reversible loss of consciousness, amnesia, analgesia, and muscle relaxation.

The depth of anesthesia can be easily adjusted during the procedure by changing the concentration of the anesthetic agent. Once the procedure is complete, the anesthetic agents are eliminated from the body through exhalation, allowing for a rapid recovery.

Inhalational anesthesia is commonly used in a wide range of surgical procedures due to its ease of administration, quick onset and offset of action, and ability to rapidly adjust the depth of anesthesia. However, it requires careful monitoring and management by trained anesthesia providers to ensure patient safety and optimize outcomes.

Intravenous injections are a type of medical procedure where medication or fluids are administered directly into a vein using a needle and syringe. This route of administration is also known as an IV injection. The solution injected enters the patient's bloodstream immediately, allowing for rapid absorption and onset of action. Intravenous injections are commonly used to provide quick relief from symptoms, deliver medications that are not easily absorbed by other routes, or administer fluids and electrolytes in cases of dehydration or severe illness. It is important that intravenous injections are performed using aseptic technique to minimize the risk of infection.

Vasopressin, also known as antidiuretic hormone (ADH), is a hormone that helps regulate water balance in the body. It is produced by the hypothalamus and stored in the posterior pituitary gland. When the body is dehydrated or experiencing low blood pressure, vasopressin is released into the bloodstream, where it causes the kidneys to decrease the amount of urine they produce and helps to constrict blood vessels, thereby increasing blood pressure. This helps to maintain adequate fluid volume in the body and ensure that vital organs receive an adequate supply of oxygen-rich blood. In addition to its role in water balance and blood pressure regulation, vasopressin also plays a role in social behaviors such as pair bonding and trust.

Organ size refers to the volume or physical measurement of an organ in the body of an individual. It can be described in terms of length, width, and height or by using specialized techniques such as imaging studies (like CT scans or MRIs) to determine the volume. The size of an organ can vary depending on factors such as age, sex, body size, and overall health status. Changes in organ size may indicate various medical conditions, including growths, inflammation, or atrophy.

Arabinose is a simple sugar or monosaccharide that is a stereoisomer of xylose. It is a pentose, meaning it contains five carbon atoms, and is classified as a hexahydroxyhexital because it has six hydroxyl (-OH) groups attached to the carbon atoms. Arabinose is found in various plant polysaccharides, such as hemicelluloses, gums, and pectic substances. It can also be found in some bacteria and yeasts, where it plays a role in their metabolism. In humans, arabinose is not an essential nutrient and must be metabolized by specific enzymes if consumed.

Liver transplantation is a surgical procedure in which a diseased or failing liver is replaced with a healthy one from a deceased donor or, less commonly, a portion of a liver from a living donor. The goal of the procedure is to restore normal liver function and improve the patient's overall health and quality of life.

Liver transplantation may be recommended for individuals with end-stage liver disease, acute liver failure, certain genetic liver disorders, or liver cancers that cannot be treated effectively with other therapies. The procedure involves complex surgery to remove the diseased liver and implant the new one, followed by a period of recovery and close medical monitoring to ensure proper function and minimize the risk of complications.

The success of liver transplantation has improved significantly in recent years due to advances in surgical techniques, immunosuppressive medications, and post-transplant care. However, it remains a major operation with significant risks and challenges, including the need for lifelong immunosuppression to prevent rejection of the new liver, as well as potential complications such as infection, bleeding, and organ failure.

In medical terms, "immersion" is not a term with a specific clinical definition. However, in general terms, immersion refers to the act of placing something or someone into a liquid or environment completely. In some contexts, it may be used to describe a type of wound care where the wound is covered completely with a medicated dressing or solution. It can also be used to describe certain medical procedures or therapies that involve submerging a part of the body in a liquid, such as hydrotherapy.

Body temperature regulation, also known as thermoregulation, is the process by which the body maintains its core internal temperature within a narrow range, despite varying external temperatures. This is primarily controlled by the hypothalamus in the brain, which acts as a thermostat and receives input from temperature receptors throughout the body. When the body's temperature rises above or falls below the set point, the hypothalamus initiates responses to bring the temperature back into balance. These responses can include shivering to generate heat, sweating to cool down, vasodilation or vasoconstriction of blood vessels to regulate heat loss, and changes in metabolic rate. Effective body temperature regulation is crucial for maintaining optimal physiological function and overall health.

Normal pressure hydrocephalus (NPH) is a type of hydrocephalus that occurs in older adults and is characterized by the accumulation of cerebrospinal fluid (CSF) in the brain's ventricles, leading to enlargement of the ventricles while maintaining normal or near-normal CSF pressure. This condition can cause a triad of symptoms including gait disturbance, cognitive impairment, and urinary incontinence.

The exact cause of NPH is not well understood, but it may be associated with conditions such as previous meningitis, subarachnoid hemorrhage, or head trauma. In some cases, the cause may be idiopathic, meaning there is no known underlying condition.

Diagnosis of NPH typically involves a combination of clinical evaluation, imaging studies (such as CT or MRI scans), and sometimes lumbar puncture to measure CSF pressure and assess the patient's response to removal of CSF. Treatment usually involves surgical implantation of a shunt system that diverts excess CSF from the ventricles to another part of the body where it can be absorbed, such as the abdominal cavity. This procedure can help alleviate symptoms and improve quality of life for some patients with NPH.

Ultrasonography, Doppler, and Duplex are diagnostic medical techniques that use sound waves to create images of internal body structures and assess their function. Here are the definitions for each:

1. Ultrasonography: Also known as ultrasound, this is a non-invasive imaging technique that uses high-frequency sound waves to produce images of internal organs and tissues. A small handheld device called a transducer is placed on the skin surface, which emits and receives sound waves. The returning echoes are then processed to create real-time visual images of the internal structures.
2. Doppler: This is a type of ultrasound that measures the velocity and direction of blood flow in the body by analyzing the frequency shift of the reflected sound waves. It can be used to assess blood flow in various parts of the body, such as the heart, arteries, and veins.
3. Duplex: Duplex ultrasonography is a combination of both gray-scale ultrasound and Doppler ultrasound. It provides detailed images of internal structures, as well as information about blood flow velocity and direction. This technique is often used to evaluate conditions such as deep vein thrombosis, carotid artery stenosis, and peripheral arterial disease.

In summary, ultrasonography is a diagnostic imaging technique that uses sound waves to create images of internal structures, Doppler is a type of ultrasound that measures blood flow velocity and direction, and duplex is a combination of both techniques that provides detailed images and information about blood flow.

Renal dialysis is a medical procedure that is used to artificially remove waste products, toxins, and excess fluids from the blood when the kidneys are no longer able to perform these functions effectively. This process is also known as hemodialysis.

During renal dialysis, the patient's blood is circulated through a special machine called a dialyzer or an artificial kidney, which contains a semi-permeable membrane that filters out waste products and excess fluids from the blood. The cleaned blood is then returned to the patient's body.

Renal dialysis is typically recommended for patients with advanced kidney disease or kidney failure, such as those with end-stage renal disease (ESRD). It is a life-sustaining treatment that helps to maintain the balance of fluids and electrolytes in the body, prevent the buildup of waste products and toxins, and control blood pressure.

There are two main types of renal dialysis: hemodialysis and peritoneal dialysis. Hemodialysis is the most common type and involves using a dialyzer to filter the blood outside the body. Peritoneal dialysis, on the other hand, involves placing a catheter in the abdomen and using the lining of the abdomen (peritoneum) as a natural filter to remove waste products and excess fluids from the body.

Overall, renal dialysis is an essential treatment option for patients with kidney failure, helping them to maintain their quality of life and prolong their survival.

Heart-assist devices, also known as mechanical circulatory support devices, are medical equipment designed to help the heart function more efficiently. These devices can be used in patients with advanced heart failure who are not responding to medication or other treatments. They work by taking over some or all of the heart's pumping functions, reducing the workload on the heart and improving blood flow to the rest of the body.

There are several types of heart-assist devices, including:

1. Intra-aortic balloon pumps (IABPs): These devices are inserted into the aorta, the large artery that carries blood from the heart to the rest of the body. The IABP inflates and deflates in time with the heartbeat, helping to improve blood flow to the coronary arteries and reduce the workload on the heart.
2. Ventricular assist devices (VADs): These devices are more invasive than IABPs and are used to support the function of one or both ventricles, the lower chambers of the heart. VADs can be used to support the heart temporarily while a patient recovers from surgery or heart failure, or they can be used as a long-term solution for patients who are not candidates for a heart transplant.
3. Total artificial hearts (TAHs): These devices replace both ventricles and all four valves of the heart. TAHs are used in patients who are not candidates for a heart transplant and have severe biventricular failure, meaning that both ventricles are no longer functioning properly.

Heart-assist devices can be life-saving for some patients with advanced heart failure, but they also carry risks, such as infection, bleeding, and device malfunction. As with any medical treatment, the benefits and risks of using a heart-assist device must be carefully weighed for each individual patient.

An acute disease is a medical condition that has a rapid onset, develops quickly, and tends to be short in duration. Acute diseases can range from minor illnesses such as a common cold or flu, to more severe conditions such as pneumonia, meningitis, or a heart attack. These types of diseases often have clear symptoms that are easy to identify, and they may require immediate medical attention or treatment.

Acute diseases are typically caused by an external agent or factor, such as a bacterial or viral infection, a toxin, or an injury. They can also be the result of a sudden worsening of an existing chronic condition. In general, acute diseases are distinct from chronic diseases, which are long-term medical conditions that develop slowly over time and may require ongoing management and treatment.

Examples of acute diseases include:

* Acute bronchitis: a sudden inflammation of the airways in the lungs, often caused by a viral infection.
* Appendicitis: an inflammation of the appendix that can cause severe pain and requires surgical removal.
* Gastroenteritis: an inflammation of the stomach and intestines, often caused by a viral or bacterial infection.
* Migraine headaches: intense headaches that can last for hours or days, and are often accompanied by nausea, vomiting, and sensitivity to light and sound.
* Myocardial infarction (heart attack): a sudden blockage of blood flow to the heart muscle, often caused by a buildup of plaque in the coronary arteries.
* Pneumonia: an infection of the lungs that can cause coughing, chest pain, and difficulty breathing.
* Sinusitis: an inflammation of the sinuses, often caused by a viral or bacterial infection.

It's important to note that while some acute diseases may resolve on their own with rest and supportive care, others may require medical intervention or treatment to prevent complications and promote recovery. If you are experiencing symptoms of an acute disease, it is always best to seek medical attention to ensure proper diagnosis and treatment.

Postoperative complications refer to any unfavorable condition or event that occurs during the recovery period after a surgical procedure. These complications can vary in severity and may include, but are not limited to:

1. Infection: This can occur at the site of the incision or inside the body, such as pneumonia or urinary tract infection.
2. Bleeding: Excessive bleeding (hemorrhage) can lead to a drop in blood pressure and may require further surgical intervention.
3. Blood clots: These can form in the deep veins of the legs (deep vein thrombosis) and can potentially travel to the lungs (pulmonary embolism).
4. Wound dehiscence: This is when the surgical wound opens up, which can lead to infection and further complications.
5. Pulmonary issues: These include atelectasis (collapsed lung), pneumonia, or respiratory failure.
6. Cardiovascular problems: These include abnormal heart rhythms (arrhythmias), heart attack, or stroke.
7. Renal failure: This can occur due to various reasons such as dehydration, blood loss, or the use of certain medications.
8. Pain management issues: Inadequate pain control can lead to increased stress, anxiety, and decreased mobility.
9. Nausea and vomiting: These can be caused by anesthesia, opioid pain medication, or other factors.
10. Delirium: This is a state of confusion and disorientation that can occur in the elderly or those with certain medical conditions.

Prompt identification and management of these complications are crucial to ensure the best possible outcome for the patient.

Coronary vessels refer to the network of blood vessels that supply oxygenated blood and nutrients to the heart muscle, also known as the myocardium. The two main coronary arteries are the left main coronary artery and the right coronary artery.

The left main coronary artery branches off into the left anterior descending artery (LAD) and the left circumflex artery (LCx). The LAD supplies blood to the front of the heart, while the LCx supplies blood to the side and back of the heart.

The right coronary artery supplies blood to the right lower part of the heart, including the right atrium and ventricle, as well as the back of the heart.

Coronary vessel disease (CVD) occurs when these vessels become narrowed or blocked due to the buildup of plaque, leading to reduced blood flow to the heart muscle. This can result in chest pain, shortness of breath, or a heart attack.

An arteriovenous shunt is a surgically created connection between an artery and a vein. This procedure is typically performed to reroute blood flow or to provide vascular access for various medical treatments. In a surgical setting, the creation of an arteriovenous shunt involves connecting an artery directly to a vein, bypassing the capillary network in between.

There are different types of arteriovenous shunts used for specific medical purposes:

1. Arteriovenous Fistula (AVF): This is a surgical connection created between an artery and a vein, usually in the arm or leg. The procedure involves dissecting both the artery and vein, then suturing them directly together. Over time, the increased blood flow to the vein causes it to dilate and thicken, making it suitable for repeated needle punctures during hemodialysis treatments for patients with kidney failure.
2. Arteriovenous Graft (AVG): An arteriovenous graft is a synthetic tube used to connect an artery and a vein when a direct AVF cannot be created due to insufficient vessel size or poor quality. The graft can be made of various materials, such as polytetrafluoroethylene (PTFE) or Dacron. Grafts are more prone to infection and clotting compared to native AVFs but remain an essential option for patients requiring hemodialysis access.
3. Central Venous Catheter (CVC): A central venous catheter is a flexible tube inserted into a large vein, often in the neck or groin, and advanced towards the heart. CVCs can be used as temporary arteriovenous shunts for patients who require immediate hemodialysis access but do not have time to wait for an AVF or AVG to mature. However, they are associated with higher risks of infection and thrombosis compared to native AVFs and AVGs.

In summary, a surgical arteriovenous shunt is a connection between an artery and a vein established through a medical procedure. The primary purpose of these shunts is to provide vascular access for hemodialysis in patients with end-stage renal disease or to serve as temporary access when native AVFs or AVGs are not feasible.

Osmolar concentration is a measure of the total number of solute particles (such as ions or molecules) dissolved in a solution per liter of solvent (usually water), which affects the osmotic pressure. It is expressed in units of osmoles per liter (osmol/L). Osmolarity and osmolality are related concepts, with osmolarity referring to the number of osmoles per unit volume of solution, typically measured in liters, while osmolality refers to the number of osmoles per kilogram of solvent. In clinical contexts, osmolar concentration is often used to describe the solute concentration of bodily fluids such as blood or urine.

A living donor is a person who voluntarily donates an organ or part of an organ to another person while they are still alive. This can include donations such as a kidney, liver lobe, lung, or portion of the pancreas or intestines. The donor and recipient typically undergo medical evaluation and compatibility testing to ensure the best possible outcome for the transplantation procedure. Living donation is regulated by laws and ethical guidelines to ensure that donors are fully informed and making a voluntary decision.

A circadian rhythm is a roughly 24-hour biological cycle that regulates various physiological and behavioral processes in living organisms. It is driven by the body's internal clock, which is primarily located in the suprachiasmatic nucleus (SCN) of the hypothalamus in the brain.

The circadian rhythm controls many aspects of human physiology, including sleep-wake cycles, hormone secretion, body temperature, and metabolism. It helps to synchronize these processes with the external environment, particularly the day-night cycle caused by the rotation of the Earth.

Disruptions to the circadian rhythm can have negative effects on health, leading to conditions such as insomnia, sleep disorders, depression, bipolar disorder, and even increased risk of chronic diseases like cancer, diabetes, and cardiovascular disease. Factors that can disrupt the circadian rhythm include shift work, jet lag, irregular sleep schedules, and exposure to artificial light at night.

Right ventricular dysfunction is a condition characterized by the impaired ability of the right ventricle (one of the two pumping chambers in the heart) to fill with blood during the diastolic phase or eject blood during the systolic phase. This results in reduced cardiac output from the right ventricle, which can lead to various complications such as fluid accumulation in the body, particularly in the abdomen and lower extremities, and ultimately congestive heart failure if left untreated.

Right ventricular dysfunction can be caused by various factors, including damage to the heart muscle due to a heart attack, high blood pressure in the lungs (pulmonary hypertension), chronic lung diseases, congenital heart defects, viral infections, and certain medications. Symptoms of right ventricular dysfunction may include shortness of breath, fatigue, swelling in the legs, ankles, or abdomen, and a decreased tolerance for physical activity.

Diagnosis of right ventricular dysfunction typically involves a combination of medical history, physical examination, imaging tests such as echocardiography, cardiac MRI, or CT scan, and other diagnostic procedures such as electrocardiogram (ECG) or cardiac catheterization. Treatment options depend on the underlying cause but may include medications to reduce fluid buildup, improve heart function, and manage symptoms, as well as lifestyle modifications such as reducing salt intake and increasing physical activity levels. In severe cases, more invasive treatments such as surgery or implantable devices like pacemakers or ventricular assist devices may be necessary.

Blood vessels are the part of the circulatory system that transport blood throughout the body. They form a network of tubes that carry blood to and from the heart, lungs, and other organs. The main types of blood vessels are arteries, veins, and capillaries. Arteries carry oxygenated blood away from the heart to the rest of the body, while veins return deoxygenated blood back to the heart. Capillaries connect arteries and veins and facilitate the exchange of oxygen, nutrients, and waste materials between the blood and the body's tissues.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

Ocular tonometry is a medical test used to measure the pressure inside the eye, also known as intraocular pressure (IOP). This test is an essential part of diagnosing and monitoring glaucoma, a group of eye conditions that can cause vision loss and blindness due to damage to the optic nerve from high IOP.

The most common method of ocular tonometry involves using a tonometer device that gently touches the front surface of the eye (cornea) with a small probe or prism. The device measures the amount of force required to flatten the cornea slightly, which correlates with the pressure inside the eye. Other methods of ocular tonometry include applanation tonometry, which uses a small amount of fluorescein dye and a blue light to measure the IOP, and rebound tonometry, which uses a lightweight probe that briefly touches the cornea and then bounces back to determine the IOP.

Regular ocular tonometry is important for detecting glaucoma early and preventing vision loss. It is typically performed during routine eye exams and may be recommended more frequently for individuals at higher risk of developing glaucoma, such as those with a family history of the condition or certain medical conditions like diabetes.

"Cold temperature" is a relative term and its definition can vary depending on the context. In general, it refers to temperatures that are lower than those normally experienced or preferred by humans and other warm-blooded animals. In a medical context, cold temperature is often defined as an environmental temperature that is below 16°C (60.8°F).

Exposure to cold temperatures can have various physiological effects on the human body, such as vasoconstriction of blood vessels near the skin surface, increased heart rate and metabolic rate, and shivering, which helps to generate heat and maintain body temperature. Prolonged exposure to extreme cold temperatures can lead to hypothermia, a potentially life-threatening condition characterized by a drop in core body temperature below 35°C (95°F).

It's worth noting that some people may have different sensitivities to cold temperatures due to factors such as age, health status, and certain medical conditions. For example, older adults, young children, and individuals with circulatory or neurological disorders may be more susceptible to the effects of cold temperatures.

The jugular venous pressure is often used to assess the central venous pressure in the absence of invasive measurements (e.g. ... The jugular venous pressure (JVP, sometimes referred to as jugular venous pulse) is the indirectly observed pressure over the ... The v wave corresponds to venous filling when the tricuspid valve is closed and venous pressure increases from venous return - ... A 1996 systematic review concluded that a high jugular venous pressure makes a high central venous pressure more likely, but ...
... is the blood pressure in the hepatic portal vein, and is normally between 5-10 mmHg. Raised portal ... WHVP is used to estimate the portal venous pressure by reflecting not the actual hepatic portal vein pressure but the hepatic ... HVPG is a clinical measurement of the pressure gradient between the WHVP and the free hepatic venous pressures (FHPV), and thus ... Kumar, A.; Sharma, P.; Sarin, S. K. (2008). "Hepatic venous pressure gradient measurement: Time to learn!". Indian Journal of ...
... and Pulmonary Capillary Wedge Monitoring Cardiovascular Physiology Central+Venous+Pressure at the U.S. ... Central venous pressure (CVP) is the blood pressure in the venae cavae, near the right atrium of the heart. CVP reflects the ... Deep inhalation Distributive shock Hypovolemia Jugular venous pressure Pulmonary capillary wedge pressure "Central Venous ... ISBN 978-0-7817-7447-5. Venous function and central venous pressure: a physiologic story - a technical discussion of the more ...
The value of ambulatory venous pressure measurements. In: Bergan JJ, Yao JST, editors. Surgery of the veins. Orlando: Grune & ... In that sense, venous blood has a greater ability to reflect light. When an arterial-venous fistulae is transluminated, there ... Venous disorders: a manual of diagnosis and treatment. Cidade: Saundres; 1995:41. Cranley, JJ. Diagnostic tests for venous ... Chronic venous thrombosis and venous insufficiency. In: Peripheral vascular sonography: a practical guide. Baltimore: Williams ...
Venous stasis causes the pressure in veins to increase. The body needs the pressure gradient between arteries and veins in ... Venous stasis results from damage to the vein valvular system in the lower extremity and in extreme cases allows the pressure ... When venous hypertension exists, arteries no longer have significantly higher pressure than veins, and blood is not pumped as ... that fails to heal spontaneously and is sustained by chronic venous disease, based on venous duplex ultrasound testing." Venous ...
355(9199): p. 200-1 Gisolf, J., et al., Human cerebral venous outflow pathway depends on posture and central venous pressure. J ... The cerebrospinal venous system (CSVS) consists of the interconnected venous systems of the brain (the cerebral venous system) ... The vertebral venous plexus is involved in regulating intracranial pressure, transmitting the influence of the respiratory and ... cardiac pressures to the intracranial compartment and equalizing the pressures within the venous system.". The continuity of ...
Valsalva maneuver - when the patient performs this maneuver, he or she, increases intra-abdominal venous pressure. If the great ... Particular veins of the deep venous system (DVS), and the superficial venous system (SVS) are looked at. The great saphenous ... Another problem when dealing with the superficial venous system, is that venous anatomy is not constant; the position of veins ... The wall thickness of the vein is significantly increased in venous reflux, being approximately 0.58 mm in venous reflux, ...
Measurement of episcleral venous pressure. Am J Ophthalmol 1978;85(1):35-42. Hayreh SS, March W, Phelps CD. Ocular hypotony ...
XXVI, p. 1. Venous pressure of man in space. J.L. Duomarco; R. Rimini; Aerospace Medicine, Vol. 41 No. 2, February 1970. One of ... Central and peripheral venous pressure in normal and pathological conditions'); Buenos Aires: López Libreros Editores SRL; 1964 ... When already a renowned investigator, enthusiastic on space travel, Duomarco published in 1970 his last paper: "Venous Pressure ... Conclusively, this book is an outstanding contribution to the rational knowledge of venous pressure physiology and ...
"Venous Function and Central Venous Pressure". Anesthesiology. 108 (4): 735-48. doi:10.1097/ALN.0b013e3181672607. PMID 18362606 ... The tendency of the arteries and veins to stretch in response to pressure has a large effect on perfusion and blood pressure. ... Pressure stockings are sometimes used to externally reduce compliance, and thus keep blood from pooling in the legs. ... Venous compliance is approximately 30 times larger than arterial compliance. Compliance is calculated using the following ...
AJR is a test for measuring jugular venous pressure (JVP) through the distention of the internal jugular vein. A positive AJR ... On an otherwise healthy individual, the jugular venous pressure remains constant or temporarily rises for a heartbeat or two, ... Does this patient have abnormal central venous pressure?". JAMA. 275 (8): 630-4. doi:10.1001/jama.1996.03530320054034. PMID ... or over the center of the abdomen for 10 seconds with a pressure of 20 to 35 mm Hg while observing the swelling of the internal ...
"The Effect of Venous Pressure on the Pulse". The Journal of Physiology. 21 (2-3): 147-159. doi:10.1113/jphysiol.1897.sp000648. ... Hill's work on blood pressure led him to believe "the arterial pressure can be taken in man as rapidly, simply, and accurately ... Pressure reduction and its effects during ascent from depth Douglas, C. G. (1953). "Leonard Erskine Hill. 1866-1952". Obituary ...
Fang, L; Baertschi, M; Mozaffarieh, M (Oct 2014). "The effect of Flammer syndrome on retinal venous pressure". BMC Ophthalmol. ... elevated retinal venous pressure, optic nerve compartmentalization, and fluctuating diffuse visual field defects. The ... "The effect of flammer-syndrome on venous retinal pressure". BMC Ophthalmology. 14: 121. doi:10.1186/1471-2415-14-121. PMC ... If blood pressure is very low, salt intake should be increased. Drugs that can lead to vasoconstriction should be avoided. If ...
... mean pulmonary venous pressure is ~5 mmHg. Local venous pressure falls to -5 at the apexes and rises to +15 mmHg at the bases, ... Permutt S, Bromberger-Barnea B, Bane HN (1962). "Alveolar Pressure, Pulmonary Venous Pressure, and the Vascular Waterfall". Med ... Pulmonary blood pressure is typically in the range 25-10 mmHg with a mean pressure of 15 mmHg. Regional arterial blood pressure ... Alveolar pressure (PA) at end expiration is equal to atmospheric pressure (0 cm H2O differential pressure, at zero flow), plus ...
It also provides a route for measuring central venous pressure. Model of human embryo, 1.3 mm. long. Scheme of placental ... Under extreme pressure, the round ligament may reopen to allow the passage of blood. Such recanalization may be evident in ... The blood pressure inside the umbilical vein is approximately 20 mmHg. The unpaired umbilical vein carries oxygen and nutrient ... In portal hypertension, the vessels surrounding the liver are subjected to abnormally high blood pressure-so high, in fact, ...
These conditions cause an increase in the central venous pressure. The lymphatic system drains into the central venous system ... However, any pathological mechanism that leads to increased central venous pressure may also cause increased lymphatic pressure ... following a negative pressure gradient to the subclavian vein via the thoracic duct or right lymphatic duct. ...
Abnormal growing central venous pressure indicates either hypotension or hypovolemia. Tachycardia accompanied by declined urine ... Typically, there is a slight increase in the diastolic blood pressure with narrowing of the pulse pressure. As diastolic ... Shock index (SI) has been defined as heart rate/systolic blood pressure ; SI≥0.6 suggests shock. Such ratio value is clinically ... Due to these factors, heart rate and blood pressure responses are extremely variable and, therefore, cannot be relied upon as ...
G.E. Burch, A Primer of Venous Pressure, Lea & Febiger publ. 1950. Second printing Charles C. Thomas 1972. G.E. Burch, J.A. ... G.E. Burch and N. DePasquale, A Primer of Clinical Measurement of Blood Pressure, C.V. Mosby publ., 1962. G.E. Burch and N. ... For example, his invention of the phlebomanometer provided a tool to measure blood flow in the venous portion of the ... He is also credited with the invention of the phlebomanometer, an instrument for measuring pressure in small veins. He ...
Such a line may be inserted for several reasons, such as to accurately measure the central venous pressure or to administer ... The pulsation seen is called the jugular venous pressure, or JVP. This is normally viewed with the patient at 45 degrees ... As the internal jugular is large, central and relatively superficial, it is often used to place central venous lines. ... This can be seen from the outside, and allows one to estimate the pressure in the atrium. ...
Elevated intracranial pressure is generally accepted to be a late effect of HACE. High central venous pressure may also occur ... Retinal venous dilation occurs in 59% of people with HACE. Rarer symptoms include brisk deep tendon reflexes, retinal ... If a lumbar puncture is performed, it will show normal cerebral spinal fluid and cell counts but an increase in pressure. In ... The leaking may be caused by increased pressure, or it may be caused by inflammation that makes the endothelium vulnerable to ...
Examination of the jugular veins may reveal elevated pressure (jugular venous distention). Examination of the lungs may reveal ... Blood pressure may be variable, and often difficult to measure as the beat-by-beat variability causes problems for most digital ... High blood pressure and valvular heart disease are the most common modifiable risk factors for AF. Other heart-related risk ... Low blood pressure is most concerning, and a sign that immediate treatment is required. Many of the symptoms associated with ...
The anterior pituitary is supplied by a low pressure portal venous system. The anterior pituitary is more commonly affected in ... as well as a slowed heart rate and low blood pressure. Adrenal gland malfunction can present acutely or chronically. In a more ... has a tendency to infarction because even small degrees of change in the pituitary intravascular pressure cause an arrest of ... Sheehan's syndrome because of the structure of the portal venous system. Posterior pituitary involvement leading to central ...
High intrathoracic pressure results in an increase in right atrial pressure, disrupting the filling of the heart and venous ... "Determinants of systemic venous return and the impact of positive pressure ventilation". Annals of Translational Medicine. 6 ( ... As venous return determines cardiac output, this results in a reduction of cardiac output. If ventilation of the lung on the ... Since the pressure is higher in the abdominal cavity than the chest cavity, rupture of the diaphragm is almost always ...
The water-filled, pulsatile pressure suits were developed to effect venous return. However, Wood and colleagues' detailed ... and calculated by subtracting pulmonary capillary wedge pressure from the mean pulmonary arterial pressure and dividing by the ... "The relationship between pulmonary artery wedge pressure and left atrial pressure in man". Circ. Res. 2 (5): 434-440. doi: ... Wood, EH; Leusen, IR; Warner, HR; Wright, JL (July 1954). "Measurement of pressures in man by cardiac catheters". Circ Res. 2 ( ...
Bainbridge reflex - increasing heart rate in response to increased central venous pressure. Baroreflex or baroreceptor reflex ... homeostatic countereffect to a sudden elevation or reduction in blood pressure detected by the baroreceptors in the aortic arch ...
The level of the jugular venous pressure (JVP) should only be commented on in this position as flatter or steeper angles lead ... Inspect the neck for increased jugular venous pressure (JVP) or abnormal waves. Any abnormal movements such as head bobbing. ... The pulses may be: Bounding as in large pulse pressure found in aortic regurgitation or CO2 retention. And the rhythm should be ... To complete the exam blood pressure should be checked, an ECG recorded, funduscopy performed to assess for Roth spots or ...
The pressure obstructs venous outflow, which causes further swelling and increased pressure. The resultant ischemia leads to ... The procedure, called a fasciotomy, involves a surgeon cutting open the skin and the fascia to relieve the pressure. Options to ... A compartment syndrome is an increased pressure within a muscular compartment that compromises the circulation to the muscles. ... The true compartment syndrome arises due to increased pressure within the unyielding anterior compartment of the leg. ...
Cardiac tamponade presents with dyspnea, tachycardia, elevated jugular venous pressure, and pulsus paradoxus. The gold standard ... Physical findings may include absent breath sounds on one side of the chest, jugular venous distension, and tracheal deviation ... low blood pressure) may warrant the use of thrombolytic drugs. Anemia that develops gradually usually presents with exertional ... and others have reported blurred vision caused by hypotension behind the eye due to a lack of oxygen and pressure; these ...
... central venous pressure and central venous oxygen saturation should be measured. Lactate should be re-measured if the initial ... fluids should be administered until the central venous pressure reaches 8-12 mmHg. Once these goals are met, the central venous ... In cases of severe sepsis and septic shock where a central venous catheter is used to measure blood pressures dynamically, ... Marik PE (June 2014). "Iatrogenic salt water drowning and the hazards of a high central venous pressure". Annals of Intensive ...
This results in a lower venous partial pressure of oxygen, which worsens hypoxia. A normally ventilated breath-hold usually ... When the pressure of gases in a bubble exceed the combined external pressures of ambient pressure and the surface tension from ... and back pressure over exhaust valves. Small variations in pressure between the delivered gas and the ambient pressure at the ... The minimum tissue and venous partial pressure of oxygen which will maintain consciousness is about 20 millimetres of mercury ( ...
The jugular venous pressure is often used to assess the central venous pressure in the absence of invasive measurements (e.g. ... The jugular venous pressure (JVP, sometimes referred to as jugular venous pulse) is the indirectly observed pressure over the ... The v wave corresponds to venous filling when the tricuspid valve is closed and venous pressure increases from venous return - ... A 1996 systematic review concluded that a high jugular venous pressure makes a high central venous pressure more likely, but ...
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I. Jugular venous pressure :. The jugular venous pressure (JVP, also known as jugular venous pulse) is the pressure over the ... Pressure at the waveforms base obliterates it. III. Causes of elevated Jugular venous pressure :. There are several causes of ... 4. Abdominal pressure. 4. Depends upon abdominal pressure. 4. Rises with abdominal pressure. ... Abnormalities of Jugular venous pressure :. We have discussed total of nine abnormalities of JVP, and they are described below ...
Venous insufficiency syndromes are most commonly caused by valvular incompetence in the low-pressure superficial venous system ... venous blood escapes from its normal antegrade path of flow and refluxes backward down the veins into an already congested leg ... Arterial inflow fills the leg veins slowly, and the only source of venous pressure is the hydrostatic pressure of a column of ... High venous pressure is directly responsible for many aspects of venous insufficiency syndrome. Under normal conditions, two ...
Central venous pressure. CVP reflects the balance between systemic venous return and cardiac output. It is best used for ... Cardiac filling pressures are measured directly from a number of sites in the vascular system. Central venous pressure (CVP) ... by alveolar pressure and bear little relation to the downstream pulmonary venous pressure or left ventricular filling pressure ... pulmonary venous pressure (Pv) and alveolar pressure (PA) 26 (Fig. 3). ...
Blood backs up in the veins, building up pressure. If not treated, increased ... Blood backs up in the veins, building up pressure. If not treated, increased ... Venous ulcers (open sores) can occur when the veins in your legs do not push blood back up to your heart as well as they should ... Venous ulcers (open sores) can occur when the veins in your legs do not push blood back up to your heart as well as they should ...
Patients with IH with low venous pressure gradient venous sinus stenosis seem to benefit equally from venous stenting compared ... To explore the possibility of benefit in low venous pressure gradient patients. METHODS:. Using a single-center, prospectively ... Venous Sinus Stenting for Low Pressure Gradient Stenoses in Idiopathic Intracranial Hypert ... Venous Sinus Stenting for Low Pressure Gradient Stenoses in Idiopathic Intracranial Hypertension. ...
Dive into the research topics of Afterload assessment with or without central venous pressure: A preliminary clinical ... Afterload assessment with or without central venous pressure: A preliminary clinical comparison. ...
Pulmonary capillary wedge pressure ,20 mm Hg. Central venous pressure ,20 mm Hg. ... CPR, cardiopulmonary resuscitation; PaO2, partial pressure of oxygen in arterial blood; F1O2, concentration of inspired oxygen. ...
Impact of sarcopenia on prognostic value of cirrhosis : going beyond the hepatic venous pressure gradient and MELD score. In: ... Impact of sarcopenia on prognostic value of cirrhosis: going beyond the hepatic venous pressure gradient and MELD score. ... Impact of sarcopenia on prognostic value of cirrhosis: going beyond the hepatic venous pressure gradient and MELD score. / Kang ... Impact of sarcopenia on prognostic value of cirrhosis: going beyond the hepatic venous pressure gradient and MELD score. ...
How is wedged hepatic venous pressure (WHVP) measured in cirrhosis?. How is the hepatic venous pressure gradient (HVPG) ... Hepatic venous pressure gradient (HVPG) measurement is the gold-standard method to assess the presence of CSPH, defined as an ... Wedged hepatic venous pressure (WHVP) is measured by inflating a balloon at the catheter tip, thus occluding a hepatic vein ... Clinically, the diagnosis may be reached if the central venous pressure is determined to be normal or if no improvement in ...
Central venous pressure monitoring kits * Arterial pressure and Swan-Ganz catheters and monitoring equipment when feasible * ... narrow pulse pressure (20 mm Hg or less) or hypotension * elevated or rising hematocrit Requirements for Inpatient Hospital ... Blood pressure cuffs (adult and pediatric) * Thermometers * Hematocrit supplies (lancets, capillary tubes, reader) * Hematocrit ... narrowed pulse pressure , 20 mm Hg, rapid and weak pulse) and with hemorrhagic manifestations (positive tourniquet tests, ...
... central venous pressure; pulmonary artery occlusion pressure; cardiac output; body temperature; arterial and mixed-venous pH, ... arterial and mixed-venous pH, PaO2, and oxygen delivery decreased, whereas PaCO2, Pva-O2, and mixed-venous partial pressure of ... Arterial and mixed-venous bicarbonate concentrations, cardiac index, stroke index, rate-pressure product, systemic and ... Mean arterial pressure, cardiac index, stroke index, rate-pressure product, left ventricular stroke work index, ...
How is wedged hepatic venous pressure (WHVP) measured in cirrhosis?. How is the hepatic venous pressure gradient (HVPG) ... Hepatic venous pressure gradient (HVPG) measurement is the gold-standard method to assess the presence of CSPH, defined as an ... Wedged hepatic venous pressure (WHVP) is measured by inflating a balloon at the catheter tip, thus occluding a hepatic vein ... Clinically, the diagnosis may be reached if the central venous pressure is determined to be normal or if no improvement in ...
Cerebrospinal fluid pressure and venous pressure in "dynamite" headache and cluster headache attacks. Headache. 32:436-438. ... Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via bioconversion to nitrite. ... Dietary nitrate attenuates oxidative stress, prevents cardiac and renal injuries, and reduces blood pressure in salt-induced ... Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric ...
Kügler, C., Strunk, M., and Rudofsky, G. (2001). Venous pressure dynamics of the healthy human leg. J. Vasc. Res. 38, 20-29. ...
ARROW, ARROWG+ARD AND ARROWG+ARD BLUE PLUS PRESSURE INJECTABLE CENTRAL VENOUS CATHETER. ...
Pressure, arterial, neuropathic (diabetic) and venous leg ulcers, including use under compression wraps ... It can be used as a primary dressing for low to highly exuding partial and full thickness dermal wounds including pressure ...
Peripheral venous pressure as a measure of compliance during a pheochromocytoma resection.Midwest Anesthesia Residents ...
Heart rate, central venous pressure, and norepinephrine, arginine vasopressin, and milrinone dosages decreased (all P < ... mean arterial blood pressure (MAP), central venous pressure, ScvO2, CI, and stroke volume index (SVI) as well as norepinephrine ... Heart rate, central venous pressure, and norepinephrine, arginine vasopressin, and milrinone dosages decreased (all P , 0.001 ... CI, cardiac index; MAP, mean arterial blood pressure; NE, norepinephrine; RBC, red blood cell; ScvO2, central venous oxygen ...
Central venous or pulmonary wedge pressure monitoring can be useful in managing severe exposures where hypotension is a risk. ... Apply direct pressure to stop any heavy bleeding.. Victim Removal. If victims can walk, lead them out of the Hot Zone to the ... Apply direct pressure to control bleeding.. Basic Decontamination. Victims who are able may assist with their own ... Higher adult systolic pressures may necessitate lower perfusion rates. For children with compromised perfusion, administer a 20 ...
Neuroscience-intracranial pressure; blast wave and impact trauma. *Cardiovascular-left ventricular pressure; arterial or venous ... Pressure measurement occurs at the exact location of interest.. FISO-LS series pressure sensors were designed as semi- ... Fiber optic blood pressure measurement system for measuring blood pressure in very small vessels, isolated hearts, etc. ... FISO-LS Fiber Optic Pressure Catheter - Standard, 2 F, 1.7 M Length, 0 to 10 Bar Please login to add to Quote ...
BP = blood pressure; CO = cardiac output; CVP = central venous pressure; PAOP = pulmonary artery occlusion pressure; PAP = ... BP = blood pressure; CO = cardiac output; CVP = central venous pressure; PAOP = pulmonary artery occlusion pressure; PAP = ... 6] EGDT target goals included maintaining a central venous pressure (CVP) of 8-12 mm Hg, an MAP of 65 mm Hg or higher, a urine ... In cardiac tamponade, there is equalization of right atrial pressure (RAP), right ventricular end-diastolic pressure (RVEDP), ...
Achieve central venous pressure (CVP) of ≥8-12 mm Hg; and. *Achieve central venous oxygen saturation (ScvO2) of Surviving ... Apply vasopressors for hypotension not responding to initial fluid resuscitation to maintain mean arterial pressure (MAP) ≥65 ... Sepsis Campaign70%. (Achieving a mixed venous oxygen saturation (SvO2) of 65% is an acceptable alternative.) ...
Non-invasive and invasive blood pressure (arterial, central venous, pulmonary artery). *Temperature ... Compressed CO2 gas simulates the signals for non-invasive blood pressure and capnography. ...
When the cause of shock is unclear, physicians may make a trial using intravenous fluids; if the central venous pressure rises ... in turn reducing the cardiac output and causing a drop in arterial blood pressure. Pressure receptors, or baroreceptors, in the ... If the blood losses continue, even these mechanisms fail, producing a sharp drop in blood pressure and overt manifestations of ... An acute loss of blood reduces the amount of venous blood returning to the heart, ...
... had a central venous oxygen saturation (ScvO2) measurement; (9) dobutamine was administered in 52%. Compliance with all actions ... central venous pressure (CVP) measurement as part of sepsis treatment/monitoring; 2) central venous oxygen saturation (ScvO2) ... had central venous measurement (CVP) measurement; (8) 17% had a central venous oxygen saturation (ScvO2) measurement; (9) ... Invasive monitoring, dependent on the placement of a central venous catheter (CVC) in the first six-hours of hospital admission ...
  • The jugular venous pressure (JVP, sometimes referred to as jugular venous pulse) is the indirectly observed pressure over the venous system via visualization of the internal jugular vein. (wikipedia.org)
  • The jugular venous pressure (JVP, also known as jugular venous pulse) is the pressure over the venous system that is indirectly measured by visualising the internal jugular vein. (medigac.com)
  • Under normal conditions, two major mechanisms in the body operate to prevent venous hypertension. (medscape.com)
  • Venous Sinus Stenting for Low Pressure Gradient Stenoses in Idiopathic Intracranial Hypertension. (bvsalud.org)
  • Medically refractory idiopathic intracranial hypertension (IIH) is frequently treated with venous sinus stenosis stenting with high success rates. (bvsalud.org)
  • 2011. Dietary nitrate attenuates oxidative stress, prevents cardiac and renal injuries, and reduces blood pressure in salt-induced hypertension. (cdc.gov)
  • High blood pressure (hypertension) is a silent condition affecting about 1 billion people globally, according to the World Health Organization. (outlookindia.com)
  • For individuals with hypertension, the increased blood pressure can strain vascular walls throughout the body, including those in the rectal area, contributing to the development and severity of hemorrhoids. (outlookindia.com)
  • This has led to unsuccessful searches for evidence of A-V shunts within the developing cerebrum, or loss of auto regulation in arterioles, producing excessive cerebral venous hypertension. (longdom.org)
  • Pulmonary hypertension is a common, complex group of disorders that result from different pathophysiologic mechanisms but are all defined by a mean pulmonary arterial pressure of 25 mm Hg or greater. (aafp.org)
  • Pulmonary hypertension is a heterogeneous group of disorders characterized by a mean pulmonary arterial pressure of 25 mm Hg or greater at rest during right heart catheterization. (aafp.org)
  • See Superficial Venous Insufficiency: Varicose Veins and Venous Ulcers , a Critical Images slideshow, to help identify the common risk factors and features of this condition and its management options. (medscape.com)
  • Venous ulcers (open sores) can occur when the veins in your legs do not push blood back up to your heart as well as they should. (medlineplus.gov)
  • Most venous ulcers occur on the leg, above the ankle. (medlineplus.gov)
  • The cause of venous ulcers is high pressure in the veins of the lower leg. (medlineplus.gov)
  • If you are at risk for venous ulcers, take the steps listed above under Wound Care. (medlineplus.gov)
  • It can be used as a primary dressing for low to highly exuding partial and full thickness dermal wounds including pressure ulcers, ulcers of the lower extremity, skin tears, donor sites, surgical wounds, abrasions, superficial and partial thickness burns. (3m.com)
  • Navigating the complexities of how systemic conditions such as high blood pressure can impact localized health issues like hemorrhoids not only enriches our understanding of human health but also opens doors to more effective treatments. (outlookindia.com)
  • The systemic venous system brings deoxygenated blood from tissues and organs back to the right atrium of the heart, whereas the pulmonary venous system brings oxygenated blood from the pulmonary circulation back to the left atrium of the heart. (medscape.com)
  • The systemic venous channels are further classified as superficial veins, deep veins, or venous sinuses. (medscape.com)
  • The intragraft pressure is then normalized to the systemic blood pressure. (medscape.com)
  • In venous insufficiency states, venous blood escapes from its normal antegrade path of flow and refluxes backward down the veins into an already congested leg. (medscape.com)
  • Venous insufficiency syndromes are most commonly caused by valvular incompetence in the low-pressure superficial venous system (see the image below) but may also be caused by valvular incompetence in the high-pressure deep venous system (or, rarely, both). (medscape.com)
  • Superficial venous insufficiency with skin changes. (medscape.com)
  • Venous insufficiency is neither uncommon nor benign. (medscape.com)
  • In venous insufficiency, after prolonged standing, the veins are completely filled, and all the venous valves float open. (medscape.com)
  • High venous pressure is directly responsible for many aspects of venous insufficiency syndrome. (medscape.com)
  • This is called venous insufficiency . (medlineplus.gov)
  • This is an early sign of venous insufficiency. (medlineplus.gov)
  • The jugular venous pulsation has a biphasic waveform. (wikipedia.org)
  • The increase in pressure and buildup of fluid prevents nutrients and oxygen from getting to tissues. (medlineplus.gov)
  • Achieving a mixed venous oxygen saturation (SvO2) of 65% is an acceptable alternative. (the-hospitalist.org)
  • The child's blood pressure, heart rate, and oxygen saturation of blood were stable during the first 20 minutes of operative time. (scielo.br)
  • The upward deflections are the "a" (atrial contraction), "c" (ventricular contraction and resulting bulging of tricuspid into the right atrium during isovolumetric systole) and "v" (venous filling). (wikipedia.org)
  • Central venous pressure reflects the pressure in the right atrium when it is filled with blood. (msdmanuals.com)
  • If the central venous pool is defined as the volume of blood contained in the great thoracic veins and in the right atrium, then VR can be considered to be the volume of blood entering this compartment from the periphery. (medscape.com)
  • For each centimeter below the right atrium, venous pressure increases by about 0.75-0.8 mm Hg. (medscape.com)
  • In contrast to venous pressure in the lower or dependent extremities, venous pressure above the right atrium decreases in the upright position. (medscape.com)
  • Deep venous thrombosis (DVT) is a manifestation of venous thromboembolism (VTE). (medscape.com)
  • CT venography showing bilateral deep venous thrombosis. (medscape.com)
  • Arrows indicate bilateral deep venous thrombosis. (medscape.com)
  • [ 2 ] and as many as 50% of those with image-documented venous thrombosis lack specific symptoms. (medscape.com)
  • Deep venous thrombosis (DVT) and pulmonary embolism (PE) are manifestations of a single disease entity, namely, venous thromboembolism (VTE). (medscape.com)
  • Various mechanisms are associated with failure of superficial venous valves. (medscape.com)
  • Congenitally abnormal valves can also be incompetent at normal superficial venous pressures. (medscape.com)
  • Using a single-center, prospectively maintained registry of patients with IIH undergoing venous stenting, we defined treatment groups by gradient pressures of ≤4, 5 to 8, and >8 mmHg based on the most frequently previously published thresholds for stenting. (bvsalud.org)
  • Patients with IH with low venous pressure gradient venous sinus stenosis seem to benefit equally from venous stenting compared with their higher gradient counterparts. (bvsalud.org)
  • Then, minor stresses such as short falls, vomiting in pyloric stenosis, violent coughing, etc., may provide sufficient extra pressure to initiate haemorrhaging. (longdom.org)
  • The basic premise is that when a stenosis is present, you will notice an increase in intragraft pressure and a decrease in access blood flow . (medscape.com)
  • Pressure receptors, or baroreceptors, in the walls of the aorta and carotid arteries trigger physiological reflexes to protect the central circulation , increasing heart rate to boost cardiac output and constricting small blood vessels to direct blood flow to essential organs. (britannica.com)
  • Radial artery and left subclavian vein catheterizations were also performed to invasively monitor BP and gauge central venous pressure (CVP). (scielo.br)
  • In central venous catheterization, a catheter is inserted into one of the large veins of the neck, upper chest, or groin. (msdmanuals.com)
  • Central venous catheterization is occasionally used to monitor central venous pressure (pressure in the superior vena cava, the large vein that returns blood to the heart from the upper part of the body). (msdmanuals.com)
  • Because central venous catheters are larger than a regular intravenous (IV) catheter and the veins in which they are placed are deeper, doctors usually inject a local anesthetic before doing the procedure. (msdmanuals.com)
  • This figure shows the blood vessel (subclavian vein) in the chest that can be used for central venous catheterization. (msdmanuals.com)
  • If these variables are kept constant, however, VR is inversely proportional to the central venous pressure (CVP). (medscape.com)
  • The term "hepatojugular reflux" was previously used as it was thought that compression of the liver resulted in "reflux" of blood out of the hepatic sinusoids into the inferior vena cava, thereby elevating right atrial pressure and visualized as jugular venous distention. (wikipedia.org)
  • We evaluated the impact of sarcopenia to the conventional prognostic factors [Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh (CTP) score, hepatic venous pressure gradient (HVPG)] in cirrhosis. (elsevierpure.com)
  • During angiography, a catheter is placed selectively via either the transjugular or transfemoral route into the hepatic vein to measure portal pressure. (medscape.com)
  • An elevated arterial or free venous serum ammonia level is the classic laboratory abnormality reported in patients with hepatic encephalopathy. (medscape.com)
  • Air trapping leads to hyperinflation and raised intrathoracic pressure, which in turn causes an increase in work of breathing and may cause air leaks (pneumothorax, pneumomediastinum, subcutaneous emphysema). (pediatriconcall.com)
  • Increased intrathoracic pressure may cause hypotension by reducing venous return. (pediatriconcall.com)
  • During the respiratory cycle, as negative intrathoracic pressure is generated during inspiration, CVP decreases, thereby increasing VR. (medscape.com)
  • Negative intrathoracic pressure is transmitted to the great thoracic veins, and as the diaphragm moves downward, intra-abdominal pressure increases, thereby helping to move blood toward the heart. (medscape.com)
  • When intrathoracic pressure increases, these mechanisms are reversed. (medscape.com)
  • Gravity affects VR by establishing a gradient between the intrathoracic venous compartment and the lower or dependent extremities. (medscape.com)
  • that high venous pressure results from inadequate venous drainage. (longdom.org)
  • Venous drainage, anterior view. (medscape.com)
  • The v wave corresponds to venous filling when the tricuspid valve is closed and venous pressure increases from venous return - this occurs during and following the carotid pulse. (wikipedia.org)
  • Arterial inflow fills the leg veins slowly, and the only source of venous pressure is the hydrostatic pressure of a column of blood as high as the nearest competent valve. (medscape.com)
  • First, bicuspid valves in the veins prevent backflow and venous pooling. (medscape.com)
  • The concept of measuring the pressure directly with in the veins, heart and arteries, originated in the minds of a German physician named Werner Forssmann in 1929, and can be considered as the first paradigm shift in hemodynamic monitoring. (ispub.com)
  • Blood backs up in the veins, building up pressure. (medlineplus.gov)
  • This leads to high pressure in the lower leg veins. (medlineplus.gov)
  • To help treat a venous ulcer, the high pressure in the leg veins needs to be relieved. (medlineplus.gov)
  • Grossly, the venous system is composed of venules and small and great veins, which serve to return blood from tissues to the heart (see the image below). (medscape.com)
  • Venous tone affects VR by modifying the capacitance of veins and is primarily regulated by the autonomous system. (medscape.com)
  • The pressure in the neck veins is close to 0 mm Hg, and this low pressure causes them to collapse. (medscape.com)
  • As blood fills the atria, the atrial walls stretch and atrial pressure decreases. (medscape.com)
  • The hydrostatic pressure increases during and immediately after ambulation, which cause venous congestion. (medscape.com)
  • Certain disorders, such as restricted arteries in the heart (coronary artery disease) or high blood pressure, gradually weaken or stiffen your heart, making it difficult to fill and pump blood properly. (medigac.com)
  • Manage your blood pressure and cholesterol levels. (medlineplus.gov)
  • Fiber optic blood pressure measurement system for measuring blood pressure in very small vessels, isolated hearts, etc. (harvardapparatus.com)
  • Compressed CO2 gas simulates the signals for non-invasive blood pressure and capnography. (laerdal.com)
  • An acute loss of blood reduces the amount of venous blood returning to the heart, in turn reducing the cardiac output and causing a drop in arterial blood pressure . (britannica.com)
  • To estimate the extent to which changes in the main coronary risk factors (serum cholesterol concentration, blood pressure, and smoking) explain the decline in mortality from ischaemic heart disease and to evaluate the relative importance of change in each of these risk factors. (bmj.com)
  • 1 To what extent changes in the important risk factors - raised serum cholesterol concentration, raised blood pressure, and smoking - explain the trends in mortality from ischaemic heart disease is an important public health question. (bmj.com)
  • The physiological connection between high blood pressure and hemorrhoids lies in the pressure exerted on blood vessels. (outlookindia.com)
  • Adopting a healthier lifestyle is pivotal in managing both high blood pressure and hemorrhoids. (outlookindia.com)
  • A diet rich in fruits, vegetables, whole grains, and lean proteins can lower blood pressure levels and reduce hemorrhoid risk by improving bowel movements and reducing straining. (outlookindia.com)
  • Beyond lifestyle changes, medication plays a crucial role in controlling high blood pressure, with a range of antihypertensive drugs available to manage the condition effectively. (outlookindia.com)
  • It decreases heart rate, blood pressure, and venous return, and it may also stimulate local histamine-mediated processes. (pharmacytimes.com)
  • This effect is due to a reduction in the perfusion pressure of the brain. (medscape.com)
  • Recognition of inadequate venous patterns may not benefit the infant itself, but may protect any siblings from loss of home and parents. (longdom.org)
  • The x descent follows the 'a' wave and corresponds to atrial relaxation and rapid atrial filling due to low pressure. (wikipedia.org)
  • After appropriate sensor calibration, completed at the factory, each etalon cavity length corresponds to a specific pressure value. (harvardapparatus.com)
  • citation needed] In a prospective randomized study involving 86 patients who underwent right and left cardiac catheterization, the abdominojugular test was shown to correlate best with the pulmonary arterial wedge pressure. (wikipedia.org)
  • To explore the possibility of benefit in low venous pressure gradient patients . (bvsalud.org)
  • Myocardial infarction (MI) is a painful condition with tightness, pressure, or squeezing pain in the chest for approximately 75% of patients who experience it. (pharmacytimes.com)
  • Venous return (VR) is the volume of blood that reaches the right heart. (medscape.com)
  • The major factors that influence VR are the respiratory cycle, venous tone, the function of the right heart, gravity, and the muscle pump. (medscape.com)
  • Most commonly, congenitally weak vein walls dilate under normal pressures to cause secondary valve failure. (medscape.com)
  • At this time, high hydrostatic venous pressure results from the unbroken column of fluid that extends from the head to the foot. (medscape.com)
  • However, if rising cerebral pressure is insufficient to cause damage at birth, the infant may survive with a chronically high cerebral venous pressure. (longdom.org)
  • Venous pressure at the level of the ankle in a person standing at the upright position is about 90 mm Hg. (medscape.com)
  • BACKGROUND: Varicoceles are associated with venous flux that may cause increased heat and interstitial pressure within the testes, but these effects are variable. (cdc.gov)
  • Patient selection has been driven almost exclusively by identification of supraphysiological venous pressure gradients across stenotic regions based on theoretical assessment of likelihood of response. (bvsalud.org)
  • Pathological investigations have found accumulations of peri-venous plasma and blood suggesting that excessive cerebral venous pressure has disrupted vessels, initiating the intra-ventricular bleeding observed. (longdom.org)
  • The signal conditioner is designed to determine the cavity length to the nanometer level, providing the researcher with an extremely accurate and repeatable pressure measurement system. (harvardapparatus.com)
  • During ambulation, the normal pressure in the venous system of the lower leg is nearly zero. (medscape.com)

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