The heart sounds "lub" and "dup" result from ________.
A) opening of the heart valves
B) firing of the nodes of the intrinsic conduction system
C) blood rushing through the chambers
D) closure of heart valves
E) contraction of the heart

Question

Quizplus · Accepted Answer

The heart sounds "lub" and "dup" are caused by the closure of the heart valves. The "lub" sound is caused by the closure of the atrioventricular valves (mitral and tricuspid) at the beginning of systole, while the "dup" sound is caused by the closure of the semilunar valves (pulmonary and aortic) at the end of systole.

The Heart Sounds "Lub" and "Dup" Result from ________