NEET2004ZoologyBody Fluids and CirculationActual
The first heart sound is produced when
Options
- Adiastole begins
- Bsemilunar valve close quickly
- Cinterventricular pressure decreases
- Dbicuspid and tricuspid valve close quickly
Correct answer
D. bicuspid and tricuspid valve close quickly
Step-by-step solution
During working of heart two sounds are produced lub and dub. First sound (i.e., lub) is produced when auriculoventricular (tricuspid and bicuspid) valves are closed or at the end of diastole. The second sound (i.e., dub) is produced when semilunar valves at the base of dorsal aorta are closed or at the end of systole.