The heart is a muscle. Its job is to pump blood throughout the body. Blood carries the oxygen and nutrients that body organs need to stay healthy and work properly.
The heart is divided into four chambers, two on the right and two on the left.
With each heartbeat, the heart sends blood throughout the body.
To do this, the left and right sides of the heart perform different tasks:
- The right side (coloured blue on the diagram) receives oxygen-poor blood from the body and pumps it into the lungs where it picks up oxygen
- The left side (coloured red) receives this oxygen-rich blood from the lungs and pumps it through the rest of the body
After delivering the oxygen, the blood returns to the heart and the cycle starts over again.