Carotid Stenosis
Narrowing or stricture of any part of the CAROTID ARTERIES, most often due to atherosclerotic plaque formation. Ulcerations may form in atherosclerotic plaques and induce THROMBUS formation. Platelet or cholesterol emboli may arise from stenotic carotid lesions and induce a TRANSIENT ISCHEMIC ATTACK; CEREBROVASCULAR ACCIDENT; or temporary blindness (AMAUROSIS FUGAX). (From Adams et al., Principles of Neurology, 6th ed, pp 822-3)
Endarterectomy, Carotid
The excision of the thickened, atheromatous tunica intima of a carotid artery.
Carotid Arteries
Carotid Artery Diseases
Pathological conditions involving the CAROTID ARTERIES, including the common, internal, and external carotid arteries. ATHEROSCLEROSIS and TRAUMA are relatively frequent causes of carotid artery pathology.
Carotid Artery, Internal
Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose.
Carotid Artery, Common
The two principal arteries supplying the structures of the head and neck. They ascend in the neck, one on each side, and at the level of the upper border of the thyroid cartilage, each divides into two branches, the external (CAROTID ARTERY, EXTERNAL) and internal (CAROTID ARTERY, INTERNAL) carotid arteries.
Aortic Valve Stenosis
A pathological constriction that can occur above (supravalvular stenosis), below (subvalvular stenosis), or at the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.
Ultrasonography, Doppler, Duplex
Ultrasonography applying the Doppler effect combined with real-time imaging. The real-time image is created by rapid movement of the ultrasound beam. A powerful advantage of this technique is the ability to estimate the velocity of flow from the Doppler shift frequency.
Endarterectomy
Surgical excision, performed under general anesthesia, of the atheromatous tunica intima of an artery. When reconstruction of an artery is performed as an endovascular procedure through a catheter, it is called ATHERECTOMY.
Ischemic Attack, Transient
Brief reversible episodes of focal, nonconvulsive ischemic dysfunction of the brain having a duration of less than 24 hours, and usually less than one hour, caused by transient thrombotic or embolic blood vessel occlusion or stenosis. Events may be classified by arterial distribution, temporal pattern, or etiology (e.g., embolic vs. thrombotic). (From Adams et al., Principles of Neurology, 6th ed, pp814-6)
Constriction, Pathologic
Stents
Angioplasty
Reconstruction or repair of a blood vessel, which includes the widening of a pathological narrowing of an artery or vein by the removal of atheromatous plaque material and/or the endothelial lining as well, or by dilatation (BALLOON ANGIOPLASTY) to compress an ATHEROMA. Except for ENDARTERECTOMY, usually these procedures are performed via catheterization as minimally invasive ENDOVASCULAR PROCEDURES.
Stroke
A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)
Cerebrovascular Disorders
A spectrum of pathological conditions of impaired blood flow in the brain. They can involve vessels (ARTERIES or VEINS) in the CEREBRUM, the CEREBELLUM, and the BRAIN STEM. Major categories include INTRACRANIAL ARTERIOVENOUS MALFORMATIONS; BRAIN ISCHEMIA; CEREBRAL HEMORRHAGE; and others.
Carotid Body
A small cluster of chemoreceptive and supporting cells located near the bifurcation of the internal carotid artery. The carotid body, which is richly supplied with fenestrated capillaries, senses the pH, carbon dioxide, and oxygen concentrations in the blood and plays a crucial role in their homeostatic control.
Carotid Artery, External
Carotid Sinus
The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure.
Tracheal Stenosis
Ultrasonography, Doppler, Transcranial
A non-invasive technique using ultrasound for the measurement of cerebrovascular hemodynamics, particularly cerebral blood flow velocity and cerebral collateral flow. With a high-intensity, low-frequency pulse probe, the intracranial arteries may be studied transtemporally, transorbitally, or from below the foramen magnum.
Magnetic Resonance Angiography
Non-invasive method of vascular imaging and determination of internal anatomy without injection of contrast media or radiation exposure. The technique is used especially in CEREBRAL ANGIOGRAPHY as well as for studies of other vascular structures.
Angiography, Digital Subtraction
A method of delineating blood vessels by subtracting a tissue background image from an image of tissue plus intravascular contrast material that attenuates the X-ray photons. The background image is determined from a digitized image taken a few moments before injection of the contrast material. The resulting angiogram is a high-contrast image of the vessel. This subtraction technique allows extraction of a high-intensity signal from the superimposed background information. The image is thus the result of the differential absorption of X-rays by different tissues.
Amaurosis Fugax
Cerebral Angiography
Radiography of the vascular system of the brain after injection of a contrast medium.
Angioplasty, Balloon
Use of a balloon catheter for dilation of an occluded artery. It is used in treatment of arterial occlusive diseases, including renal artery stenosis and arterial occlusions in the leg. For the specific technique of BALLOON DILATION in coronary arteries, ANGIOPLASTY, BALLOON, CORONARY is available.
Carotid Artery Thrombosis
Blood clot formation in any part of the CAROTID ARTERIES. This may produce CAROTID STENOSIS or occlusion of the vessel, leading to TRANSIENT ISCHEMIC ATTACK; CEREBRAL INFARCTION; or AMAUROSIS FUGAX.
Risk Factors
Pyloric Stenosis
Narrowing of the pyloric canal with varied etiology. A common form is due to muscle hypertrophy (PYLORIC STENOSIS, HYPERTROPHIC) seen in infants.
Severity of Illness Index
Intracranial Embolism
Mitral Valve Stenosis
Narrowing of the passage through the MITRAL VALVE due to FIBROSIS, and CALCINOSIS in the leaflets and chordal areas. This elevates the left atrial pressure which, in turn, raises pulmonary venous and capillary pressure leading to bouts of DYSPNEA and TACHYCARDIA during physical exertion. RHEUMATIC FEVER is its primary cause.
Ultrasonography
Prospective Studies
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.
Pulmonary Valve Stenosis
Treatment Outcome
Follow-Up Studies
Blood Flow Velocity
Arterial Occlusive Diseases
Ultrasonography, Doppler, Color
Ultrasonography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region.
Intracranial Arteriosclerosis
Vascular diseases characterized by thickening and hardening of the walls of ARTERIES inside the SKULL. There are three subtypes: (1) atherosclerosis with fatty deposits in the ARTERIAL INTIMA; (2) Monckeberg's sclerosis with calcium deposits in the media and (3) arteriolosclerosis involving the small caliber arteries. Clinical signs include HEADACHE; CONFUSION; transient blindness (AMAUROSIS FUGAX); speech impairment; and HEMIPARESIS.
Predictive Value of Tests
In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.
Ultrasonography, Doppler
Ultrasonography applying the Doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. (Stedman, 25th ed)
Brain Ischemia
Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.
Cerebrovascular Circulation
The circulation of blood through the BLOOD VESSELS of the BRAIN.
Retrospective Studies
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.
Tomography, X-Ray Computed
Carotid Artery Injuries
Damages to the CAROTID ARTERIES caused either by blunt force or penetrating trauma, such as CRANIOCEREBRAL TRAUMA; THORACIC INJURIES; and NECK INJURIES. Damaged carotid arteries can lead to CAROTID ARTERY THROMBOSIS; CAROTID-CAVERNOUS SINUS FISTULA; pseudoaneurysm formation; and INTERNAL CAROTID ARTERY DISSECTION. (From Am J Forensic Med Pathol 1997, 18:251; J Trauma 1994, 37:473)
Postoperative Complications
Arteriosclerosis
Thickening and loss of elasticity of the walls of ARTERIES of all sizes. There are many forms classified by the types of lesions and arteries involved, such as ATHEROSCLEROSIS with fatty lesions in the ARTERIAL INTIMA of medium and large muscular arteries.
Sensitivity and Specificity
Tunica Intima
Risk Assessment
Time Factors
Elements of limited time intervals, contributing to particular results or situations.
Embolism
Tunica Media
The middle layer of blood vessel walls, composed principally of thin, cylindrical, smooth muscle cells and elastic tissue. It accounts for the bulk of the wall of most arteries. The smooth muscle cells are arranged in circular layers around the vessel, and the thickness of the coat varies with the size of the vessel.
Carotid Intima-Media Thickness
A measurement of the thickness of the carotid artery walls. It is measured by B-mode ULTRASONOGRAPHY and is used as a surrogate marker for ATHEROSCLEROSIS.
Cerebral Infarction
The formation of an area of NECROSIS in the CEREBRUM caused by an insufficiency of arterial or venous blood flow. Infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., INFARCTION, ANTERIOR CEREBRAL ARTERY), and etiology (e.g., embolic infarction).
Observer Variation
The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).
Retinal Artery Occlusion
Doppler Effect
Middle Cerebral Artery
The largest of the cerebral arteries. It trifurcates into temporal, frontal, and parietal branches supplying blood to most of the parenchyma of these lobes in the CEREBRAL CORTEX. These are the areas involved in motor, sensory, and speech activities.
Cranial Nerve Injuries
Dysfunction of one or more cranial nerves causally related to a traumatic injury. Penetrating and nonpenetrating CRANIOCEREBRAL TRAUMA; NECK INJURIES; and trauma to the facial region are conditions associated with cranial nerve injuries.
Hemodynamics
Patient Selection
Renal Artery Obstruction
Narrowing or occlusion of the RENAL ARTERY or arteries. It is due usually to ATHEROSCLEROSIS; FIBROMUSCULAR DYSPLASIA; THROMBOSIS; EMBOLISM, or external pressure. The reduced renal perfusion can lead to renovascular hypertension (HYPERTENSION, RENOVASCULAR).
Intracranial Embolism and Thrombosis
Reproducibility of Results
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Aortic Stenosis, Subvalvular
A pathological constriction occurring in the region below the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.
Acetazolamide
One of the CARBONIC ANHYDRASE INHIBITORS that is sometimes effective against absence seizures. It is sometimes useful also as an adjunct in the treatment of tonic-clonic, myoclonic, and atonic seizures, particularly in women whose seizures occur or are exacerbated at specific times in the menstrual cycle. However, its usefulness is transient often because of rapid development of tolerance. Its antiepileptic effect may be due to its inhibitory effect on brain carbonic anhydrase, which leads to an increased transneuronal chloride gradient, increased chloride current, and increased inhibition. (From Smith and Reynard, Textbook of Pharmacology, 1991, p337)
Atherosclerosis
Life Tables
Aortic Stenosis, Supravalvular
A pathological constriction occurring in the region above the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.
Vertebrobasilar Insufficiency
Localized or diffuse reduction in blood flow through the vertebrobasilar arterial system, which supplies the BRAIN STEM; CEREBELLUM; OCCIPITAL LOBE; medial TEMPORAL LOBE; and THALAMUS. Characteristic clinical features include SYNCOPE; lightheadedness; visual disturbances; and VERTIGO. BRAIN STEM INFARCTIONS or other BRAIN INFARCTION may be associated.
Coronary Angiography
Magnetic Resonance Imaging
Collateral Circulation
Carotid Artery, Internal, Dissection
The splitting of the vessel wall in one or both (left and right) internal carotid arteries (CAROTID ARTERY, INTERNAL). Interstitial hemorrhage into the media of the vessel wall can lead to occlusion of the internal carotid artery and aneurysm formation.
Catheterization
Carotid Body Tumor
Benign paraganglioma at the bifurcation of the COMMON CAROTID ARTERIES. It can encroach on the parapharyngeal space and produce dysphagia, pain, and cranial nerve palsies.
Coronary Artery Bypass
Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion.
Blood Vessel Prosthesis
Embolic Protection Devices
Coronary Disease
An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.
Disease Progression
Laryngostenosis
Aortic Valve
Radiology, Interventional
Coronary Artery Disease
Odds Ratio
The ratio of two odds. The exposure-odds ratio for case control data is the ratio of the odds in favor of exposure among cases to the odds in favor of exposure among noncases. The disease-odds ratio for a cohort or cross section is the ratio of the odds in favor of disease among the exposed to the odds in favor of disease among the unexposed. The prevalence-odds ratio refers to an odds ratio derived cross-sectionally from studies of prevalent cases.
Tricuspid Valve Stenosis
The pathologic narrowing of the orifice of the TRICUSPID VALVE. This hinders the emptying of RIGHT ATRIUM leading to elevated right atrial pressure and systemic venous congestion. Tricuspid valve stenosis is almost always due to RHEUMATIC FEVER.
Reoperation
A repeat operation for the same condition in the same patient due to disease progression or recurrence, or as followup to failed previous surgery.
Age Factors
Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.
Ophthalmic Artery
Image Processing, Computer-Assisted
Chi-Square Distribution
A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.
Discrete Subaortic Stenosis
A type of constriction that is caused by the presence of a fibrous ring (discrete type) below the AORTIC VALVE, anywhere between the aortic valve and the MITRAL VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.
Cohort Studies
Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.
Intraoperative Complications
Peripheral Vascular Diseases
Prevalence
Incidence
The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.
Rupture, Spontaneous
Pyloric Stenosis, Hypertrophic
Imaging, Three-Dimensional
The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.
Comorbidity
The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival.
Preoperative Care
Care given during the period prior to undergoing surgery when psychological and physical preparations are made according to the special needs of the individual patient. This period spans the time between admission to the hospital to the time the surgery begins. (From Dictionary of Health Services Management, 2d ed)
Ferrosoferric Oxide
Pulsatile Flow
Heart Valve Prosthesis Implantation
Filtration
ROC Curve
Aspirin
The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. (From Martindale, The Extra Pharmacopoeia, 30th ed, p5)
Myocardial Infarction
NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).
Blood Vessel Prosthesis Implantation
Logistic Models
Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.
Hypertension
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.
Platelet Aggregation Inhibitors
Risk
Multivariate Analysis
A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.
Case-Control Studies
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
Brain
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Prognosis
Ultrasonics
A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.
Cardiac Catheterization
Biological Markers
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
Sex Factors
Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.
Echocardiography
Randomized Controlled Trials as Topic
Regression Analysis
Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.
Survival Rate
The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.
Chemoreceptor Cells
Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.
Coronary Circulation
The circulation of blood through the CORONARY VESSELS of the HEART.
Proportional Hazards Models
Statistical models used in survival analysis that assert that the effect of the study factors on the hazard rate in the study population is multiplicative and does not change over time.
Time
Diagnostic Imaging
Single-Blind Method
C-Reactive Protein
Vertebral Artery
Hydroxymethylglutaryl-CoA Reductase Inhibitors
Fractional Flow Reserve, Myocardial
The ratio of maximum blood flow to the MYOCARDIUM with CORONARY STENOSIS present, to the maximum equivalent blood flow without stenosis. The measurement is commonly used to verify borderline stenosis of CORONARY ARTERIES.
Linear Models
Kaplan-Meier Estimate
A nonparametric method of compiling LIFE TABLES or survival tables. It combines calculated probabilities of survival and estimates to allow for observations occurring beyond a measurement threshold, which are assumed to occur randomly. Time intervals are defined as ending each time an event occurs and are therefore unequal. (From Last, A Dictionary of Epidemiology, 1995)
Image Enhancement
Arteriovenous Shunt, Surgical
Intracranial Arterial Diseases
Pathological conditions involving ARTERIES in the skull, such as arteries supplying the CEREBRUM, the CEREBELLUM, the BRAIN STEM, and associated structures. They include atherosclerotic, congenital, traumatic, infectious, inflammatory, and other pathological processes.
Analysis of Variance
Heart Valve Prosthesis
Vasomotor System
Brain Infarction
Tissue NECROSIS in any area of the brain, including the CEREBRAL HEMISPHERES, the CEREBELLUM, and the BRAIN STEM. Brain infarction is the result of a cascade of events initiated by inadequate blood flow through the brain that is followed by HYPOXIA and HYPOGLYCEMIA in brain tissue. Damage may be temporary, permanent, selective or pan-necrosis.
Image Interpretation, Computer-Assisted
Nervous System Diseases
Diseases of the central and peripheral nervous system. This includes disorders of the brain, spinal cord, cranial nerves, peripheral nerves, nerve roots, autonomic nervous system, neuromuscular junction, and muscle.
Dogs
Pressoreceptors
Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.
Hypertension, Renovascular
Hypertension due to RENAL ARTERY OBSTRUCTION or compression.
Radiation Injuries
Hypotension
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.
Greece
Circle of Willis
A polygonal anastomosis at the base of the brain formed by the internal carotid (CAROTID ARTERY, INTERNAL), proximal parts of the anterior, middle, and posterior cerebral arteries (ANTERIOR CEREBRAL ARTERY; MIDDLE CEREBRAL ARTERY; POSTERIOR CEREBRAL ARTERY), the anterior communicating artery and the posterior communicating arteries.
Jugular Veins
Veins in the neck which drain the brain, face, and neck into the brachiocephalic or subclavian veins.