It likewise opens due to a build-up of pressure, this time in the left atrium. The semilunar valves stop the back flow of blood into the heart. There is a semilunar valve where the aorta leaves ...

Regurgitation through an atrioventricular valve is reflected by abnormalities of atrial pressure curves. Semilunar-valve regurgitation causes alterations of the arterial pressures on the ...