Question

Read the following statements carefully and select correct choice from given.
(a) First heart sound lub is produced due to closure of atrioventricular valves.
(b) First heart sound is of longer duration than second heart sound dub.

• A. (a) is correct but (b) is wrong
• B. (b) is correct but (a) is wrong
• C. Both (a) and (b) are correct
• D. Both (a) & (b) are wrong

Answer 1

The correct option is A (a) is correct but (b) is wrong

The first heart sound - lubb is created by the closure of atrioventricular valves at the beginning of ventricular systole and also it is more complex, louder and lasts longer than the second sound - dubb.

So, the correct answer is 'Both a and b are correct'.