Why Does Your Heart Beat?

Heart: The Engine of Life Educational Resources—The Franklin Institute

What causes your heart to beat? Think of your arteries as the pump behind the thump.

When someone takes your pulse, they’re actually measuring the contractions of your arteries.

Here’s why: The heart pumps oxygen-rich blood to the rest of the body through one main artery called the aorta. The muscular walls of the aorta and the other arteries help the heart pump blood.

When the heart beats, arteries expand as they fill with blood. When the heart relaxes, the arteries contract. It’s this rhythm between the heart and the arteries that powers your circulation system and keeps your blood flowing.