How the Heart Works - Topic Overview
The heart is at the center of your circulatory system, which is a
network of blood vessels that delivers blood to every part of your body. Blood
carries oxygen and other important nutrients that all body organs need to stay
healthy and to work properly.
Your heart is a muscle, and its job is to pump blood throughout your
How does my heart pump blood?
Your heart is divided into two separate pumping systems, the right
side and the left side.
- The right side of your heart receives
oxygen-poor blood from your veins and pumps it to your lungs, where it picks up
oxygen and gets rid of carbon dioxide.
- The left side of your heart
receives oxygen-rich blood from your lungs and pumps it through your arteries
to the rest of your body.
Your heart has
four separate chambers that pump blood, two on the right side and two on the
How does blood flow through the heart?
Blood flows through your heart and lungs in four steps:
- The right atrium receives oxygen-poor blood
from the body and pumps it to the right ventricle through the tricuspid
- The right ventricle pumps the oxygen-poor blood to the lungs
through the pulmonary valve.
- The left atrium receives oxygen-rich
blood from the lungs and pumps it to the left ventricle through the mitral
- The left ventricle pumps the oxygen-rich blood through the
aortic valve out to the rest of the body.
The left and right atria are smaller chambers that pump blood into
the ventricles. The left and right ventricles are stronger pumps. The left
ventricle is the strongest because it has to pump blood out to the entire body.
When your heart functions normally, all four chambers work together in a
continuous and coordinated effort to keep oxygen-rich blood circulating
throughout your body. Your heart has its own electrical system that coordinates
the work of the heart chambers (heart rhythm) and also controls the frequency
of beats (heart rate).