Cardiac Cycle – The performance of the human heart from the beginning of one heartbeat to the beginning of the next

(Pronounced kar-dee-ak sai-kul)

We know that cardiac is relating to the heart. So the cycle of the heart system is simply the heart cycle. It's the hearts cycle from the beginning of one heart beat to the beginning of the next.

This is the heart:

Note: it may help to learn the mnemonic for the order of the heart valves. Go to Try Pulling My Aorta.

Note: Diastole means relax and systole means squeeze.

The following will show you the cardiac cycle.

The cardiac cycle refers to the sequence of events that occur in the heart during one complete heartbeat, including the contraction and relaxation of the heart muscle (systole and diastole). Electric impulses within the heart control the contraction and relaxation of the heart chambers.