NAVLE® Question of the day

MO TU WED TH FR

April 24, 2024

NAVLE

One description of a typical heart sound is "lub-dub."

What makes the first heart sound (S1) (i.e., the "lub")?

A - Aortic and pulmonic valves shut and the mitral and tricuspid valves open

B - End of rapid ventricular filling period

C - Closure of atrioventricular valves, opening of semilunar valves

D - Rapid atrial and auricular expansion due to cranial and caudal vena cavae contraction

E - Atrial contraction