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The heart is a muscular organ situated in the mediastinum.It consists of four chambers, four valves, two main arteries (the coronary arteries), and the conduction system. The left and right sides of the heart have different functions: the right side receives de-oxygenated blood through the superior and inferior venae cavae and pumps blood to the lungs through the pulmonary artery, and the left ...
A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart. A mammalian heart usually has four valves. Together, the valves determine the direction of blood flow through the heart. Heart valves are opened or closed by a difference in blood pressure on each side. [1] [2] [3]
The action potential passes along the cell membrane causing the cell to contract, therefore the activity of the sinoatrial node results in a resting heart rate of roughly 60–100 beats per minute. All cardiac muscle cells are electrically linked to one another, by intercalated discs which allow the action potential to pass from one cell to the ...
Coronary artery disease (CAD) or ischemic heart disease are the terms used to describe narrowing of the coronary arteries. [8] As the disease progresses, plaque buildup can partially block blood flow to the heart muscle. Without enough blood supply , the heart is unable to work properly, especially under increased stress.
A valve prolapse can result in mitral insufficiency, which is the regurgitation or backflow of blood from the left ventricle to the left atrium due to the incomplete closure of the valve causing a systolic murmur heard at the apex of the heart. This increase in pressure in the left atrium and pulmonary circuit can lead to symptoms like fatigue ...
In the anatomy of the heart, the valve of the coronary sinus (also called the Thebesian valve, after Adam Christian Thebesius [1] [2] [3]) is a valve located at the orifice of the coronary sinus where the coronary sinus drains into the right atrium. [4] It prevents blood from flowing backwards into the coronary sinus during contraction of the ...
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.
The rapid reperfusion of heart muscle is critical in preventing further heart muscle damage caused by heart attacks, this time is often referred to as 'Onset-to-Door' and 'Door-to-balloon' time, shortening this time is an important goal within an emergency care/ hospital setting. A number of initiatives have been active sponsored by a variety ...