Functions & parts

the heart pumps deoxygenated blood to the lungs first and pumps oxygenated blood throughout the body second.

4 chambers- 2 atria, 2 ventricles
2 valves to prevent blood back flow
SA node to regulate heartbeat

heart consists of:

how the heart works//
1. the heart muscle relaxes and fills with blood
2. The SA node is a group of cells that sends electrical signals to make cardiac muscle contract
3. Then the muscle contracts and pumps blood forward