About the heart
- The circulatory system transports substances around the body.
- The heart is an organ and pumps blood around the body.
- Much of the wall of the heart is made from muscle tissue.
- There are four main chambers (left and right atria and ventricles) of the heart.
Sequence of blood in the heart
- Blood enters the atria of the heart.
- The atria contract and force blood into the ventricles.
- The ventricles contract and force blood out of the heart.
- Valves in the heart ensure that blood…