Question

Which of the following statements is true with respect to sounds produced during cardiac cycle?

• A. The first heart sound $\left(\text{lub}\right)$ is associated with the closure of tricuspid and bicuspid valves.
• B. Second heart sound $\left(\text{dub}\right)$ is associated with closure of bicuspid valve.
• C. The first heart sound $\text{(lub)}$ is associated with the closure of semilunar valve.
• D. Second heart sound $\left(\text{dub}\right)$ is associated with closure of tricuspid valve.

Answer 1

The correct option is A

The first heart sound $\left(\text{lub}\right)$ is associated with the closure of tricuspid and bicuspid valves.

True statement

The first heart sound $\left(\text{lub}\right)$ is associated with the closure of tricuspid and bicuspid valves.

Elaboration

Heart produces two sounds during a cardiac cycle: Lub and dub. Lub is the first heart sound which is produced due to sharp closure of the atrio-ventricular valves, i.e., bicuspid and tricuspid valves at the beginning of ventricular systole.

Hence, the given statement is correct.

Final answer

$\left(B\right)$ The first heart sound $\left(\text{lub}\right)$ is associated with the closure of tricuspid and bicuspid valves.