Question

In cardiac cycle, maximum time is taken by

• A. Atria systole
• B. Atria diastole
• C. Ventricle systole
• D. Ventricle Diastole

Answer 1

Answer: (B)

Atria diastole

The cardiac cycle is the event during, which one heartbeat or one cycle of contraction(systole) and relaxation (diastole) of cardiac muscle occurs. A cardiac cycle consists of systole and diastole of atria and systole and diastole of ventricles. The time of cardiac cycle is in reverse ratio of the rate of heartbeat. In man, the heart rate is about $72$ times $/$ min, therefore the time of a cardiac cycle is $60/72=0.8$ sec approx. The total time of the cardiac cycle is divided into atrial systole 0.1 sec, atrial diastole 0.7 sec, ventricular systole 0.3 seconds and ventricular diastole 0.5 seconds.

So, the correct answer is option D.