Question

how would you describe the event s2?
turbulence caused by the closure of the semilunar valves
turbulence caused by the openings of the semilunar valves
turbulence caused by the closure of the atrioventricular valves
turbulence caused by the openings of the atrioventricular valves
save for later

Explanation:

The second heart - sound (S2) is produced by the closure of the semilunar valves (aortic and pulmonary valves). When these valves close, it creates turbulence that results in the S2 sound.

Answer:

turbulence caused by the closure of the semilunar valves