The time gap in the passage of action potential from sino-atrial node to the ventricles allow ventricles to relax. The ventricular pressure falls, causing the closure of semilunar valves, which prevent the backflow of blood into the ventricles.
The time gap in the passage of action potential from sino-atrial node to the ventricles allow ventricles to relax. The ventricular pressure falls, causing the closure of semilunar valves, which prevent the backflow of blood into the ventricles.