anatomy, the heart valves are valves in the heartthat maintain the unidirectional flow of blood by opening and closing depending on the difference in pressure on each side. The mechanical equivalent of the heart valves would be the reed valves which is another type of valve.
There are four valves of the heart (not counting the
valve of the coronary sinusand valve of the inferior vena cava):
* The two "atrioventricular (AV) valves" ensure blood flows from the atria to the ventricles, and not the other way.
* The two "semilunar (SL) valves" are present in the arteries leaving the heart, and they prevent blood flowing back from the arteries into the ventricles.
The sound of the heart valves shutting causes the
These are small, single cuspid valves that prevent backflow from the ventricles into the atria during
systole. They are anchored to the wall of the ventricle by chordae tendineae, that prevent the valve from inverting.
chordae tendineaeare attached to papillary muscles that cause tension to better hold the valve. Together, the papillary muscles and the chordae tendinae are known as the subvalvular apparatus. The function of the subvalvular apparatus is to keep the valves from prolapsing into the atria when they close. The subvalvular apparatus have no effect on the opening and closure of the valves, however. This is caused entirely by the pressure gradient across the valve.
Also known as the "bicuspid valve", the mitral valve gets its name from the resemblance to a
bishop's mitre(a type of hat). It prevents blood flowing from the left ventricleinto the left atrium. It is on the left side of the heart and has two cusps.
A common complication of
rheumatic feveris thickening and stenosisof the mitral valve.
The tricuspid valve is on the right side of the heart, between the
right atriumand the right ventriclewhich stops the backflow of blood between the two.
These are positioned on the
pulmonary arteryand the aorta. These valves do not have chordae tendinae, but are more similar to valves in veins.
The aortic valve lies between the
left ventricleand the aorta. The aortic valve has three cusps. During ventricular systole, pressure rises in the left ventricle. When the pressure in the left ventricle rises above the pressure in the aorta, the aortic valve opens, allowing blood to exit the left ventricle into the aorta. When ventricular systole ends, pressure in the left ventricle rapidly drops. When the pressure in the left ventricle decreases, the aortic pressure forces the aortic valve to close. The closure of the aortic valve contributes the A2 component of the second heart sound(S2).
The most common congenital abnormality of the heart is the
bicuspid aortic valve. In this condition, instead of three cusps, the aortic valve has two cusps. This condition is often undiagnosed until the person develops calcific aortic stenosis. Aortic stenosis occurs in this condition usually in patients in their 40s or 50s, an average of over 10 years earlier than in people with normal aortic valves.
The pulmonic valve lies between the
right ventricleand the pulmonary arteryand also has three cusps.
* Disorders of the valves (
Valvular heart disease)
** Aortic valve disorders:
Aortic valve replacement
Aortic valve repair
** Mitral valve disorders
Mitral valve prolapse
Mitral valve replacement
Mitral valve repair
Pulmonic valve disorders
Tricuspid valve disorders
Congenital heart disease
Artificial heart valve
* [http://www.mitralvalverepair.org/content/view/51/ Mitral Valve Repair at The Mount Sinai Hospital] - "Mitral Valve Anatomy"
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Look at other dictionaries:
heart valve — n any of the valves that control blood flow to and from the heart and that include the atrioventricular valves, the aortic valve, and the pulmonary valve called also cardiac valve … Medical dictionary
heart valve — noun 1. a valve to control one way flow of blood • Syn: ↑cardiac valve • Hypernyms: ↑valve • Hyponyms: ↑atrioventricular valve, ↑semilunar valve • Part Holonyms: ↑ … Useful english dictionary
heart valve — noun The valves in heart which prevent blood from moving wrong direction … Wiktionary
heart valve — membrane that controls the flow of blood in and out of the heart … English contemporary dictionary
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