Final answer:
The heart sound associated with S2 occurs as the ventricles relax and the semilunar valves close.
Step-by-step explanation:
In a normal, healthy heart, the heart sound associated with S2 occurs as the ventricles relax and the semilunar valves close. S2 is the sound of the closing of the semilunar valves during ventricular diastole. When the ventricles contract to eject blood into the pulmonary trunk and aorta, the semilunar valves open.
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