Cardiovascular physiology

A vein () is a blood vessel in the circulatory system of humans and most other animals that carries blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins.

An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in the pulmonary circulation that carry blood to the lungs for oxygenation, and the umbilical arteries in the fetal circulation that carry deoxygenated blood to the placenta. It consists of a multi-layered artery wall wrapped into a tube-shaped channel.

pressure exerted by circulating blood upon the walls of blood vessels

In medicine, pulse is the rhythmic expansion and contraction of an artery in response to the cardiac cycle (heartbeat). The pulse may be felt (palpated) in any place that allows an artery to be compressed near the surface of the body, such as at the neck (carotid artery), wrist (radial artery or ulnar artery), at the groin (femoral artery), behind the knee (popliteal artery), near the ankle joint (posterior tibial artery), and on foot (dorsalis pedis artery). The pulse is most commonly measured at the wrist or neck for adults and at the brachial artery (inner upper arm between the shoulder and

chamber of the heart

number of contractions (beats) of the heart per minute (bpm)

hormone system that is involved in the regulation of the plasma sodium concentration and arterial blood pressure

thumb|254x254px|Normal blood vessel (left) vs. vasodilation (right) Vasodilation, also known as vasorelaxation, is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. Blood vessel walls are composed of endothelial tissue and a basal membrane lining the lumen of the vessel, concentric smooth muscle layers on top of endothelial tissue, and an adventitia over the smooth muscle layers. Relaxation of the smooth muscle layer allows the blood vessel to dilate, as it is held

An exudate is a fluid released by an organism through pores or a wound, a process known as exuding or exudation. Exudate is derived from exude 'to ooze' from Latin 'to (ooze out) sweat' ('''' 'out' and '''' 'to sweat').

performance of the heart from the end of one heartbeat to the beginning of the next

Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in controlling hemorrhage and reducing acute blood loss. When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular resistance. This makes the skin turn paler because less blood reaches the surface, reducing the radiation of heat. On a larger leve

term used in cardiac physiology that describes the volume of blood being pumped by the heart, in particular by the left or right ventricle, per unit time

Hemodynamics or haemodynamics are the dynamics of blood flow. The circulatory system is controlled by homeostatic mechanisms of autoregulation, just as hydraulic circuits are controlled by control systems. The hemodynamic response continuously monitors and adjusts to conditions in the body and its environment. Hemodynamics explains the physical laws that govern the flow of blood in the blood vessels.

volume of blood pumped from the left ventricle per beat

thumb|upright|A Charles Lindbergh|Lindbergh perfusion pump, , an early device for simulating natural perfusion

relationship between stroke volume and end diastolic volume

Transudate is extravascular fluid with low protein content and a low specific gravity (< 1.012). It has low nucleated cell counts (less than 500 to 1000 per microliter) and the primary cell types are mononuclear cells: macrophages, lymphocytes and mesothelial cells. For instance, an ultrafiltrate of blood plasma is transudate. It results from increased fluid pressures or diminished colloid oncotic forces in the plasma.

blood pressure in the venae cavae, near the right atrium of the heart

diagram in thermodynamics, ploting pressure versus volume, typically used for thermodynamic processes

An inotrope or inotropic is a drug or any substance that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions. Positively inotropic agents increase the strength of muscular contraction.

increase in heart rate due to an increase in central venous pressure

fraction of blood ejected from a ventricle of the heart with each heartbeat

difference between the systolic and diastolic pressure readings

physiological response to immersion of air-breathing vertebrates

REDIRECT Vascularisation#Vasculogenesis

ratio of the blood pressure at the ankle to the blood pressure in the upper arm

a mechanism that maintains blood pressure between two heart beats

physiological nervous system response to increased intracranial pressure

400px|thumb|Flowchart showing baroreceptor reflex

Chronotropic effects (from chrono-, meaning time, and tropos, "a turn") are those that change the heart rate.

hormonal system of blood proteins that play a role in inflammation, blood pressure control, coagulation and pain

Measurement of blood volume

thumb|Ventricular systole. Red arrow is path from left ventricle to aorta. Afterload is largely dependent upon aortic pressure. Afterload is the pressure that the heart must work against to eject blood during systole (ventricular contraction). Afterload is proportional to the average arterial pressure. As aortic and pulmonary pressures increase, the afterload increases on the left and right ventricles respectively. Afterload changes to adapt to the continually changing demands on an animal's cardiovascular system. Afterload is proportional to mean systolic blood pressure and is measured in mil

tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen (anoxia, hypoxia)

end diastolic volume in the heart

volume of blood in the circulatory system of an individual

haemodynamic parameter that relates the cardiac output (CO) from left ventricle in one minute to body surface area (BSA), thus relating heart performance to the size of the individual

standard diagram used in cardiac physiology named after Dr. Carl J. Wiggers

description of net flow of fluid across a semipermeable membrane

resistance that must be overcome to push blood through the circulatory system and create flow

attribute of blood vessels

pressure measured by wedging a pulmonary catheter with an inflated balloon into a small pulmonary arterial branch

thumb | right The term dromotropic derives from the Greek word δρόμος drómos, meaning "running", a course, a race. A dromotropic agent is one which affects the conduction speed (in fact the magnitude of delay) in the AV node, and subsequently the rate of electrical impulses in the heart.

ability of a biological organ to distend

test for the time taken for color to return to an external capillary bed after pressure is applied to cause blanching

the rate of blood flow back to the heart. It normally limits cardiac output.

volume of blood in a ventricle at the end of contraction, or systole, and the beginning of filling, or diastole

blood pressure in a vein of the neck

study of the circulatory system, specifically addressing the physiology of the heart ("cardio") and blood vessels ("vascular")

The multicellular organismal process in which the heart decreases in volume in a characteristic way to propel blood through the body.

ability of the heart and lungs to supply oxygen-rich blood to the working muscle tissues and the ability of the muscles to use oxygen to produce energy for movement

volume of arterial blood effectively perfusing tissue

blood pressure at the root of aorta

how arteries and arterioles react to an increase or decrease of blood pressure to keep the blood flow within the blood vessel constant

graph showing the relationship between right atrial pressure (x-axis) and cardiac output (y-axis

agent that has a strengthening effect on the heart or that can increase cardiac output. for e.g . cardiac glycosides.

of the heart