The sound of a human heartbeat as heard through a stethoscope is caused by the closing of valves within the heart.

Question

Quizplus · Accepted Answer

The sound of the human heartbeat as heard through a stethoscope is caused by the closing of valves within the heart. The two main sounds are "lub" and "dub." The "lub" sound is caused by the closing of the atrioventricular valves, while the "dub" sound is caused by the closing of the semilunar valves.

The Sound of a Human Heartbeat as Heard Through a Stethoscope