Discussion of the Shiley Heart Valve Failure
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An atrioventricular valve separates the atrium from the ventricle. The left atrioventricular valve is called the mitral valve, but is sometimes referred to as the bicuspid valve because it has two cusps. Semilunar valves separate the ventricles from the outgoing blood vessels. The right valve is called the pulmonary valve because it leads to the lungs, while the left valve is known as the aortic valve because it leads to the aorta.
When the ventricle expands, the atrioventricular valve allows blood to flow forward from the atrium into the ventricle while the semilunar valve keeps blood that has already been pumped out of the heart from flowing back in. Heart valve diseases fall into one of two categories: stenosis (hardening of the valve) or incompetence (allowance of backflow). This causes the stenotic valves not to open fully, requiring more work to push the liquid through the valve. By contrast, incompetent valves waste work by allowing blood to flow backward. Rheumatic fever stiffens valve tissue, causing stenosis. Bacterial infection of the heart can cause inflammation of valves, tissue scarring, or permanent degradation...