# GROSS ANATOMY

## GROSS ANATOMY

### HEART MEDIASTINUM

 Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
The length of the cardiac cycle is normally ____ second(s) in length.
 A 2 B 4 C 0.8 D 0.3
Explanation:

Detailed explanation-1: -The total period of the cardiac cycle is 0.8 seconds which includes a cardiac diastole of 0.4 seconds, a ventricular systole of 0.3 seconds and an atrial systole of 0.1 seconds.

Detailed explanation-2: -The heart beats 72 times per minute, i.e., that many cardiac cycles are performed per minute. From this it could be deduced that the duration of a cardiac cycle is 0.8 seconds. During a cardiac cycle, each ventricle pumps out approximately 70 mL of blood, which is called the stroke volume.

Detailed explanation-3: -The normal duration of the cardiac cycle is 0.8 second. Atrial systole-0.1 sec. Atrial diastole-0.7 sec.

Detailed explanation-4: -Cardiac Cycle Each of these cycles starts with the depolarization of the SA node which is then followed by the atrial systole [0.1 seconds], then ventricular systole [0.3 seconds], followed by the diastole of the complete heart [0.4 seconds].

Detailed explanation-5: -There is an inverse relationship between the duration of cardiac cycle and heart rate. Hence when the heart rate is increased to 120 beats per minute, the cardiac cycle duration will be about 0.5 sec.

There is 1 question to complete.