Question

multiple choice question
heart sounds are generated when blood vibrates the wall of the heart due to the ______ of the valves.
opening
stretching
closing

Explanation:

Heart sounds are primarily produced when the heart valves close, causing blood to vibrate the heart - wall. When valves open, the sound is much less prominent compared to the sound generated during valve - closure. Valve stretching is not the main cause of heart sounds.

Answer:

C. closing