The heart is the fluid pump of the cardiovascular system. It pumps blood and nutrients to all of the organs of the body. And it pumps blood to the lungs where it receives oxygen after the body has used it up. This is the process called oxygenation. It’s included in this module as one of the steps in the heartbeat cycle.

This module shows you the four chambers of the heart and how those chambers work in a continuous cycle that receives blood in the right and left atria and then pumps blood out from the right and left ventricles.

The heart could not move blood like a fluid pump without its four valves. These valves open to allow blood to flow through and then close to prevent blood from flowing backwards.

The animation in this module shows you the heartbeat cycle in motion. Click any of the buttons to stop the animation and learn more about the anatomy and flow at that step in the cycle.