What Causes The Lub Dub Sound Of The Heart Guide

The "dub" is caused by the closure of the semilunar valves: the aortic valve and the pulmonary valve. When the ventricles finish contracting and begin to relax, the pressure within the ventricles drops below the pressure in the aorta and pulmonary artery.

After the upper chambers (atria) pump blood into the lower chambers (ventricles), the atrioventricular (AV) valves —the mitral and tricuspid valves—snap shut. what causes the lub dub sound of the heart

Leads from the right ventricle to the lungs. The "dub" is caused by the closure of