What is are heat sounds ? How are they produced ?

Explanation

1. Rhythmic contraction and expansion of heart is called heart beat.
2. The contraction of the heart is called systole and the relaxation of the heart is called diastole.
3. The heart normally beats 70-72 times per min in a human adult.
4. During each cardiac cycle two sounds are produced that can be heard through a stethoscope.
The first heart sound (lub) is associated with the closure of the tricuspid and bicuspid valves whereas second heart sound (dub) is associated with the closure of the semilunar valves. These sounds are of clinical diagnostic significance.