Blood Vessels & Circulation

Blood circulation from the heart into the rest of the body with arrows describing the direction of blood flow. Deoxygenated blood in blue, oxygenated blood in red.

Blood vessels are tubes that carry blood to and from all parts of the body.

There are two main types of blood vessels:

  • Arteries transport oxygenated blood away from the heart to other parts of the body
  • Veins return deoxygenated blood from other parts of the body back toward the heart.

The aorta is the largest artery in the human body. It starts at the left ventricle of the heart and runs down to the abdomen, where it branches out into smaller arteries that supply blood to all parts of the body.

The largest veins of the human body are the superior and inferior venae cavae, which both empty into the right atrium of the heart. The superior vena cava carries the deoxygenated blood from the upper part of the body, while the inferior vena cava drains the lower half of the body.

Discover the anatomy and physiology of the main arteries and veins with interactive animations and diagrams. Learn even faster with this blood vessel anatomy study guide.