One of the four structures within the heart that prevent backflow of blood by opening and closing with each heartbeat. The valves include two semilunar valves, the aortic and pulmonary; the mitral or bicuspid valve; and the tricuspid valve. The valves permit blood flow in only one direction.
hog:0001393
semilunar valvehog:0001472
atrioventricular valveBFO:0000050
part of
hog:0000276