Question

First heart sound is produced due to

• A. closure of the tricuspid
• B. closure of the bicuspid
• C. closure of the semilunar valves
• D. both a and b

Answer 1

The correct option is D both a and b

During each cardiac cycle two prominent sounds are produced which can be easily heard through a stethoscope. The first heart sound (lub) is associated with the closure of the tricuspid and bicuspid valves whereas the second heart sound (dub) is associated with the closure of the semilunar valves. These sounds are of clinical diagnostic significance.