Q. During each cardiac cycle, prominant sounds are produced which can be easily heard through stethoscope. They are
A) Lub
B) Dub
C) Tick
D) Both (a) and (b)
Explanation
The closing of atrioventricular valves during ventricular systole produces the first heart sound, lub. During ventricular diastole, the semilunar valves are closed and blood is forced back into the ventricles. Due to the high pressure developed in the vessels, this causes the second heart sound, dub
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.