What occurs during the time between the first heart sound and the second heart sound?

A) Ventricular systole
B) Ventricular diastole
C) Ventricular filling
D) Atrial systole
E) The P wave of the ECG

First Heart Sound

The sound produced by the closure of the AV (mitral and tricuspid) valves at the beginning of ventricular contraction or systole.

Second Heart Sound

The second heart sound is produced by the closing of the aortic and pulmonary valves at the beginning of ventricular diastole.

Ventricular Systole

The phase of the cardiac cycle in which the ventricles contract, pumping blood out of the heart into the arterial system.