When the aortic semilunar valve closes and blood bounces off of it, it produces the ________ heart sound that is ultimately related to when the ________.

A) lubb (S1) ; atria contract
B) dupp (S2) ; atria relax
C) lubb (S1) ; ventricles contract
D) dupp (S2) ; ventricles relax
E) lubb (S1) ; ventricles relax

Aortic Semilunar Valve

The valve that regulates blood flow from the heart into the aorta, preventing backflow into the ventricle.

Lubb (S1)

The sound made by the closure of the mitral and tricuspid valves at the beginning of systole, commonly referred to as the "first heart sound."

Dupp (S2)

The sound made by the heart's valves closing in the cardiac cycle, often associated with the splitting or duplication of the second heart sound.