NEETZoologyBody Fluids and Circulation
What causes the ventricular pressure to decline during the cardiac cycle?
Options
- AThe contraction of the ventricles and atria
- BThe relaxation of the ventricles and atria
- CThe opening of the tricuspid and bicuspid valves
- DThe closure of the tricuspid and bicuspid valves
Correct answer
A. The contraction of the ventricles and atria
Step-by-step solution
The ventricles now relax (ventricular diastole) and the ventricular pressure falls causing the closure of semilunar valves which prevents the backflow of blood into the ventricles. As the ventricular pressure declines further, the tricuspid and bicuspid valves are pushed open by the pressure in the atria exerted by the blood which was being emptied into them by the veins. The blood now once again moves freely to the ventricles.