Question

But what is the benefit of these valves during lub dap

Why AV valves closed during beginning of systole ❓whereas SV closed at the end of systole ❓

Answer 1

Answer:AV valves are closed during beginning of systole because to prevent backflow from ventricles into atria and therefore no blood enters the ventricle after closing AV valves.AV valves are closed when ventricular pressure exceeds atrial pressure.

SV valves are closed at the end of systole to prevent backflow from aorta and pulmonary trunk to respective left ventricle and right ventricle.SV valves are closed when arterial pressure exceeds ventricular pressure.