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Cardiovascular System

The cardiovascular system or circulatory system is made up of structures and organs that aid in blood flow throughout the body.

What does the cardiovascular system do?

The main goals of this system are to:

  • Get rid of waste products in the body like carbon dioxide
  • Carry oxygen rich blood and nutrients to cells in the body

Parts of the cardiovascular system

The organs of the cardiovascular system include the:

  • Heart
  • Lungs
  • Veins
  • Arteries

The heart

The heart is a muscle that pumps blood to organs and tissues in the body.

The heart has 2 upper chambers (atria) and 2 lower chambers (ventricles) that work together to move blood through the body. Heart valves keep blood moving in the right direction and prevent flow backwards.

How does blood flow through the body?

Veins carry oxygen-poor blood from tissues in the body to the heart. Oxygen-rich blood is carried away from the heart through the arteries.

  • The right atrium (upper chamber) collects oxygen-poor blood from the body through the superior vena cava and inferior vena cava (two large veins), then pumps it to the right ventricle through the tricuspid valve.
  • The right ventricle (lower chamber) pumps the oxygen-poor blood through the pulmonary valve into the main pulmonary artery, which splits into the left and right pulmonary arteries. These carry the blood to the lungs, where it picks up oxygen and gets rid of carbon dioxide.
  • The left atrium (upper chamber) receives oxygen-rich blood from lungs through the pulmonary veins, then pumps it to the left ventricle through the mitral valve.
  • The left ventricle (lower chamber) pumps oxygen-rich blood through the aortic valve into the aorta (the largest artery in the body), which carries it to the rest of the body.

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The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

Last Revised: May 19, 2025

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