Question

During the isovolumic relaxation phase of ventricular diastole, __________.

Select one:

a. the atrioventricular valves remain open

b. the ventricles fill with blood

c. the ventricles eject blood

d. the ventricular volume is at its minimum

Answer 1

Ans- b. the ventricles fill with the blood

Isometric relaxation is a type of muscular reaction in which there is decrease in tension without any change in length of muscle fibres. Isometric relaxation of ventricular muscles is called isovolumetric relaxation. It means there is no change in volume. During this period all the valves of heart are first closed. Now, both ventricles relax as closed cavity without any change in volume or length of muscle fibre. Intraventricular pressure decreases during this period. When the ventricular pressure becomes less than the pressure in atria, the atrioventricular valves open. Thus the fall in pressure in the ventricles, caused by isometric relaxation is responsible for atrioventricular valves which results in the filling of the ventricles.