When auscultating heart sounds, S1 is caused by blood turbulence associated with closure of the _____ valves soon after ventricular _____ begins.
A) AV; diastole
B) Semilunar; systole
C) AV; systole
D) Semilunar; diastole

Question

Quizplus · Accepted Answer

S1 heart sound is caused by the closure of the atrioventricular (AV) valves (mitral and tricuspid valves) at the beginning of ventricular systole, when the ventricles start to contract. This marks the start of systole.

When Auscultating Heart Sounds, S1 Is Caused by Blood Turbulence