The Second Heart Sound _______

Question

The second heart sound _______.
A) marks the beginning of ventricular diastole
B) is caused by the closure of the semilunar valves
C) is caused by the closure of the AV valves
D) answers A and B are correct

Accepted Answer

The second heart sound is associated with the closure of the semilunar valves (aortic and pulmonary valves), which marks the beginning of ventricular diastole. This event is what generates the "dub" sound in the heart's "lub-dub" cycle.