If heart beats 75 beats/min. then what is time for cardiac cycle ?

• 0.5 sec

• 0.8 sec

• 1 sec

• 1.5 sec

B.

0.8 sec

In human beings, the cardiac cycle takes about 0.8 second.

The time for auricular systole is 0.1 second and that for auricular diastole is 0.7 second. Ventricular systole, which consists of the compression period (0.1 sec) and the expression period (0.2 second) takes 0.3 second and ventricular diastole takes 0.5 second. Hence, the total systole occupies 0.4 second and joint diastole 0.4 second.

Therefore, if heart beats 75 beats/min, then the time for one complete cardiac cycle is 0.8 sec.