Medicine & Health
How does the heart pump blood?
The heart works as a muscular double pump: its chambers contract in a coordinated rhythm to push blood to the lungs to pick up oxygen, then around the body to deliver it — returning for another cycle.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how the heart works.
Step by step
- 1Four chambers: two atria (receive blood) and two ventricles (pump it out).
- 2The right side sends blood to the lungs; the left side pumps it to the body.
- 3Valves keep blood flowing one way only.
- 4An electrical signal sets the steady beat.
Frequently asked questions
- What are the heart's chambers?
- Two atria on top that receive blood and two ventricles below that pump it out.
- Why does the heart have two sides?
- The right side pumps blood to the lungs for oxygen; the left pumps oxygen-rich blood to the rest of the body.
- What makes the heart beat?
- A natural electrical signal (from the sinoatrial node) triggers each coordinated contraction.