The first heart sound occurs due to

Question

The first heart sound occurs due to (A) opening of semilunar valve (B) closing of semilunar valve (C) onset of auricular systole (D) sudden closure of AV valves

Tardigrade Admin · Accepted Answer

The atrioventricular (AV) valve closes due to sharp rise of intraventricular pressure, thus closing of it produces first heart sound 'lub'.

Q. The first heart sound occurs due to

opening of semilunar valve

closing of semilunar valve

onset of auricular systole

sudden closure of AV valves

The atrioventricular (AV) valve closes due to sharp rise of intraventricular pressure, thus closing of it produces first heart sound 'lub'.