Question

contruction phase of cardiac cycle?

Answer 1

The cardiac cycle is divided onto two phases:

• Contraction phase called systole
• Relaxation phase called diastole

Contraction phase of cardiac cycle involves two events. They are atrial systole and ventricular systole.

Atrial systole: lasts about 0.1 seconds. When both the atria is filled with blood, the atrias contracts and the blood is pushed down into the left and right ventricles simultaneously through the bicuspid and tricuspid valves.

Ventricular systole: last for about 0.3 seconds. When the blood from atria reaches the ventricles, the bicuspid and tricuspid valves closes and the ventricles contracts. This forces the blood of right ventricule into lungs via pulmonary trunk and left ventricle to various part of the body via aorta.