The resistance to the flow of either alternating or direct electrical current.
A type of impedance plethysmography in which bioelectrical impedance is measured between electrodes positioned around the neck and around the lower thorax. It is used principally to calculate stroke volume and cardiac volume, but it is also related to myocardial contractility, thoracic fluid content, and circulation to the extremities.
Recording changes in electrical impedance between electrodes placed on opposite sides of a part of the body, as a measure of volume changes in the path of the current. (Stedman, 25th ed)
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).
In about 250 species of electric fishes, modified muscle fibers forming disklike multinucleate plates arranged in stacks like batteries in series and embedded in a gelatinous matrix. A large torpedo ray may have half a million plates. Muscles in different parts of the body may be modified, i.e., the trunk and tail in the electric eel, the hyobranchial apparatus in the electric ray, and extrinsic eye muscles in the stargazers. Powerful electric organs emit pulses in brief bursts several times a second. They serve to stun prey and ward off predators. A large torpedo ray can produce of shock of more than 200 volts, capable of stunning a human. (Storer et al., General Zoology, 6th ed, p672)
1,4:3,6-Dianhydro D-glucitol. Chemically inert osmotic diuretic used mainly to treat hydrocephalus; also used in glaucoma.
The region of the thorax that includes the PLEURAL CAVITY and MEDIASTINUM.
Act of listening for sounds within the heart.
The sounds heard over the cardiac region produced by the functioning of the heart. There are four distinct sounds: the first occurs at the beginning of SYSTOLE and is heard as a "lubb" sound; the second is produced by the closing of the AORTIC VALVE and PULMONARY VALVE and is heard as a "dupp" sound; the third is produced by vibrations of the ventricular walls when suddenly distended by the rush of blood from the HEART ATRIA; and the fourth is produced by atrial contraction and ventricular filling.
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.
The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.
The graphic recording of chest wall movement due to cardiac impulses.
Graphic registration of the heart sounds picked up as vibrations and transformed by a piezoelectric crystal microphone into a varying electrical output according to the stresses imposed by the sound waves. The electrical output is amplified by a stethograph amplifier and recorded by a device incorporated into the electrocardiograph or by a multichannel recording machine.
A technique of measuring the dielectric properties of materials, which vary over a range of frequencies depending on the physical properties of the material. The technique involves measuring, over a range of frequencies, ELECTRICAL IMPEDANCE and phase shift of an electric field as it passes through the material.
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.
Fields representing the joint interplay of electric and magnetic forces.
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.
An order of neotropical electric fish found chiefly in the waters of South America. They continually emit weak electric discharges, which they use in object location and communication. A most popular species of research interest is the electric eel, ELECTROPHORUS electricus.

Electric impedance is a measure of opposition to the flow of alternating current (AC) in an electrical circuit or component, caused by both resistance (ohmic) and reactance (capacitive and inductive). It is expressed as a complex number, with the real part representing resistance and the imaginary part representing reactance. The unit of electric impedance is the ohm (Ω).

In the context of medical devices, electric impedance may be used to measure various physiological parameters, such as tissue conductivity or fluid composition. For example, bioelectrical impedance analysis (BIA) uses electrical impedance to estimate body composition, including fat mass and lean muscle mass. Similarly, electrical impedance tomography (EIT) is a medical imaging technique that uses electric impedance to create images of internal organs and tissues.

Impedance cardiography is a non-invasive method to measure cardiac output and systemic vascular resistance. It uses low-frequency electrical currents passed through the thorax to measure changes in impedance or resistance to flow during each heartbeat. This allows for the calculation of stroke volume and cardiac output. Impedance cardiography can provide continuous, real-time monitoring of cardiovascular function, making it useful in critical care settings and for tracking changes in patients with heart failure or other cardiovascular conditions.

Impedance plethysmography is a non-invasive method used to measure changes in blood volume or flow in a particular area of the body. It works by passing a small electrical current through the tissue and measuring the opposition (impedance) to that current, which varies with the amount of blood present in the area.

In impedance cardiography, this technique is used to estimate cardiac output, stroke volume, and other hemodynamic parameters. The changes in impedance are measured across the chest wall, which correlate with the ventricular ejection of blood during each heartbeat. This allows for the calculation of various cardiovascular variables, such as the amount of blood pumped by the heart per minute (cardiac output) and the resistance to blood flow in the systemic circulation (systemic vascular resistance).

Impedance plethysmography is a safe and reliable method for assessing cardiovascular function, and it has been widely used in clinical settings to evaluate patients with various cardiovascular disorders, including heart failure, hypertension, and peripheral arterial disease.

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.

An Electric organ is a specialized electric tissue found in some groups of fish, most notably in the electric eels and electric rays. It consists of modified muscle or nerve cells called electrocytes, which are capable of generating and transmitting electrical signals. These organs are used for various purposes such as navigation, communication, and hunting. In electric eels, for example, the electric organ can generate powerful electric shocks to stun prey or defend against predators.

Isosorbide is a type of sugar alcohol (a sugary-tasting substance that is not actually sugar) used as a low-calorie sweetener and sugar substitute in various food and pharmaceutical products. It is also used as an active ingredient in some medications for treating chest pain (angina) and heart failure.

Medically, isosorbide can exist in two forms: isosorbide dinitrate and isosorbide mononitrate. These are both vasodilators, meaning they relax and widen blood vessels, improving blood flow and reducing the workload on the heart. Isosorbide dinitrate is often used to prevent angina attacks, while isosorbide mononitrate is used for both prevention and treatment of angina.

It's important to note that overuse of sugar alcohols like isosorbide can lead to digestive issues such as bloating, diarrhea, and gas due to their incomplete absorption in the gut.

The thoracic cavity is the medical term for the chest region that lies between the neck and the diaphragm. It is one of the main body cavities, enclosed by the ribcage and protected by the sternum in front and the vertebral column behind. This cavity contains vital organs such as the heart and lungs, along with the esophagus, trachea, thoracic aorta, and various nerves and blood vessels. The thoracic cavity is lined by a serous membrane called the pleura, which covers the lungs (visceral pleura) and lines the inner surface of the chest wall (parietal pleura). This cavity plays a crucial role in respiration and protection of vital organs.

Heart auscultation is a medical procedure in which a healthcare professional uses a stethoscope to listen to the sounds produced by the heart. The process involves placing the stethoscope on various locations of the chest wall to hear different areas of the heart.

The sounds heard during auscultation are typically related to the opening and closing of the heart valves, as well as the turbulence created by blood flow through the heart chambers. These sounds can provide important clues about the structure and function of the heart, allowing healthcare professionals to diagnose various cardiovascular conditions such as heart murmurs, valvular disorders, and abnormal heart rhythms.

Heart auscultation is a key component of a physical examination and requires proper training and experience to interpret the findings accurately.

Heart sounds are the noises generated by the beating heart and the movement of blood through it. They are caused by the vibration of the cardiac structures, such as the valves, walls, and blood vessels, during the cardiac cycle.

There are two normal heart sounds, often described as "lub-dub," that can be heard through a stethoscope. The first sound (S1) is caused by the closure of the mitral and tricuspid valves at the beginning of systole, when the ventricles contract to pump blood out to the body and lungs. The second sound (S2) is produced by the closure of the aortic and pulmonary valves at the end of systole, as the ventricles relax and the ventricular pressure decreases, allowing the valves to close.

Abnormal heart sounds, such as murmurs, clicks, or extra sounds (S3 or S4), may indicate cardiac disease or abnormalities in the structure or function of the heart. These sounds can be evaluated through a process called auscultation, which involves listening to the heart with a stethoscope and analyzing the intensity, pitch, quality, and timing of the sounds.

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.

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.

Kinetocardiography (often abbreviated as KCG) is not a widely recognized or established medical term. However, in general terms, it appears to refer to a method of measuring and recording the motion or vibrations of the chest wall that may be related to cardiac activity. It's possible that this term is used in some specific research or technical contexts, but it does not have a standardized medical definition.

It's important to note that there is another term called "ballistocardiography" (BCG) which is a non-invasive method of measuring the mechanical forces generated by the heart and great vessels during each cardiac cycle. BCG can provide information about various aspects of cardiovascular function, such as stroke volume, contractility, and vascular compliance. However, kinetocardiography does not seem to be synonymous with ballistocardiography or any other established medical technique.

Phonocardiography is a non-invasive medical procedure that involves the graphical representation and analysis of sounds produced by the heart. It uses a device called a phonocardiograph to record these sounds, which are then displayed as waveforms on a screen. The procedure is often used in conjunction with other diagnostic techniques, such as electrocardiography (ECG), to help diagnose various heart conditions, including valvular heart disease and heart murmurs.

During the procedure, a specialized microphone called a phonendoscope is placed on the chest wall over the area of the heart. The microphone picks up the sounds generated by the heart's movements, such as the closing and opening of the heart valves, and transmits them to the phonocardiograph. The phonocardiograph then converts these sounds into a visual representation, which can be analyzed for any abnormalities or irregularities in the heart's function.

Phonocardiography is a valuable tool for healthcare professionals, as it can provide important insights into the health and functioning of the heart. By analyzing the waveforms produced during phonocardiography, doctors can identify any potential issues with the heart's valves or other structures, which may require further investigation or treatment. Overall, phonocardiography is an essential component of modern cardiac diagnostics, helping to ensure that patients receive accurate and timely diagnoses for their heart conditions.

Dielectric spectroscopy is a type of material characterization technique that measures the dielectric properties of a material as a function of frequency. The dielectric property of a material refers to its ability to store electrical energy in the form of polarization when an external electric field is applied. In dielectric spectroscopy, the material's response to an alternating electric field is measured, and the resulting complex permittivity (which includes both real and imaginary components) is used to characterize the material's dielectric behavior.

The technique involves applying a small amplitude AC voltage to the material while measuring the current flow through it. The frequency of the applied voltage can be varied over a wide range, typically from millihertz to gigahertz. By analyzing the phase shift and amplitude of the resulting current, the complex permittivity of the material can be determined as a function of frequency.

Dielectric spectroscopy is widely used in materials science, physics, chemistry, and biology to study the structure, dynamics, and composition of various materials, including polymers, ceramics, glasses, colloids, and biological tissues. The technique can provide valuable information about the material's molecular mobility, relaxation processes, conductivity, and other dielectric properties, which can be used for quality control, process monitoring, and fundamental research.

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.

Electromagnetic fields (EMFs) are invisible forces that result from the interaction between electrically charged objects. They are created by natural phenomena, such as the Earth's magnetic field, as well as by human-made sources, such as power lines, electrical appliances, and wireless communication devices.

EMFs are characterized by their frequency and strength, which determine their potential biological effects. Low-frequency EMFs, such as those produced by power lines and household appliances, have frequencies in the range of 0 to 300 Hz. High-frequency EMFs, such as those produced by wireless communication devices like cell phones and Wi-Fi routers, have frequencies in the range of 100 kHz to 300 GHz.

Exposure to EMFs has been linked to a variety of health effects, including increased risk of cancer, reproductive problems, neurological disorders, and oxidative stress. However, more research is needed to fully understand the potential health risks associated with exposure to EMFs and to establish safe exposure limits.

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.

Gymnotiformes is not a medical term, but a taxonomic category in biology. It refers to a order of ray-finned fishes also known as knifefish or Neotropical eels. These fish are characterized by their elongated, eel-like bodies and the ability to generate electric fields for navigation and communication. They are primarily found in freshwater environments of Central and South America.

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