During exercise,the time spent in diastole and systole
A)remains unchanged.
B)is decreased equally.
C)is decreased,with the greatest decrease occurring in diastole.
D)is increased.

Question

Quizplus · Accepted Answer

During exercise, the heart rate increases, which reduces the time spent in both diastole and systole. However, the greater reduction occurs in diastole. This is because during exercise, the demand for oxygen and nutrients by the muscles increases, and the heart responds by increasing its pumping rate, which reduces the amount of time spent in diastole, the relaxing phase of the cardiac cycle.

During Exercise,the Time Spent in Diastole and Systole