Atrial systole is responsible for the first heart sound, whereas the ventricular systole is responsible for the second heart sound.

Question

Quizplus · Accepted Answer

The atrial systole is actually silent and does not produce any heart sound. The first heart sound (S1) is caused by the closure of the mitral and tricuspid valves during ventricular contraction, which marks the beginning of the ventricular systole. The second heart sound (S2) is caused by the closure of the aortic and pulmonary valves during ventricular relaxation, marking the end of the ventricular systole.

Atrial Systole Is Responsible for the First Heart Sound, Whereas