The Second Heart Sound is Caused by the Closing of the _____

Question

The second heart sound is caused by the closing of the _____ valve(s).
A) mitral
B) semilunar
C) tricuspid
D) both A and C

Accepted Answer

The second heart sound (S2) is caused by the closing of the semilunar valves, which are the aortic and pulmonary valves. The mitral and tricuspid valves are responsible for the first heart sound (S1) which is the sound of blood being forced into the ventricles during contraction.