The second heart sound, dup, is produced by the closure of the
Correct answer: B. semilunar valves
- A. atrioventricular valves
- B. semilunar valves
- C. coronary valves
- D. pulmonary veins
Explanation
When the ventricles relax, blood trying to flow back snaps the aortic and pulmonary semilunar valves shut, producing the shorter, sharper second sound. The first sound, lubb, comes from the atrioventricular valves closing.
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About Human Heart
The human heart is a four chambered muscular pump that maintains double circulation through the pulmonary and systemic circuits. Questions cover atria, ventricles, valves, major blood vessels, the cardiac cycle, pressure changes, the conduction system and ECG, while distinguishing arteries and veins from the chambers that receive or eject blood.
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