The second heart sound (dub) results from the closing of the _________ valves in the beginning of __________.

Question

Quizplus · Accepted Answer

The second heart sound (dub) occurs during ventricular diastole, which is when the heart is relaxed and filling with blood. During this phase, the semilunar valves, located at the base of the pulmonary artery and aorta, close to prevent blood from flowing back into the ventricles. Therefore, choice C is the best answer as it correctly identifies the valves involved and the phase of the cardiac cycle.

The Second Heart Sound (Dub) Results from the Closing of the _________