Question

The second heart sound during the cardiac cycle is produced by the:

• A. (A) Simultaneous opening of the atrioventricular valves
• B. (B) Simultaneous closure of the atrioventricular valves
• C. (C) Simultaneous opening of the semilunar valves
• D. (D) Simultaneous closure of the semilunar valves

Answer 1

Answer: (D)

(D) Simultaneous closure of the semilunar valves

Answer 2

Explanation:
The second heart sound during the cardiac cycle is produced by the simultaneous closure of the semilunar valves.The second heart sound (S2) is produced by the closure of the aortic (A2) and the pulmonary valves (P2) at the end of systole. Refer to the audio example below. A2 is best heard at the aortic area (second right intercostal space); P2 is best heard at the pulmonary area.Hence, the correct option is (D).