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How the Heart Works

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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 circulatory system.

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 camera.gif that pump blood, two on the right side and two on the left.

How does blood flow through the heart?

Blood flows through your heart and lungs camera.gif in four steps:

  1. The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle through the tricuspid valve.
  2. The right ventricle pumps the oxygen-poor blood to the lungs through the pulmonary valve.
  3. The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle through the mitral valve.
  4. 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).

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WebMD Medical Reference from Healthwise

Last Updated: April 26, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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