Circulatory System


The circulatory (cardiovascular) system transports blood to and from the heart with the help of blood vessels.

The heart is the center of the circulatory system and pumps blood across the entire body via arteries and veins:

  • Arteries transport blood away from the heart toward other body parts. Arteries usually carry oxygen-rich blood. The smallest arteries, called arterioles, branch off larger arteries in order to supply body tissue with blood.
  • Veins return the blood back to the heart. They usually carry deoxygenated blood. They branch into smaller venules to pick up oxygen-poor blood from the body tissue.

Learn the anatomy and physiology of the circulatory system (cardiovascular system) with the interactive animations below, and test your knowledge with labeling worksheets.