Human circulatory system has three types of blood vessels , the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart.
| Arteries | Veins |
|---|---|
| Arteries are blood vessels that carry blood away from heart . | Veins are blood vessels that carry blood form all parts of body to heart . |
| Arteries carry oxygenated blood with exception of Pulmonary artery and Umbilical Artery . The pulmonary artery carries blood from the heart to the lungs, where it receives oxygen. The other unique artery is the umbilical artery, which carries deoxygenated blood from a fetus to its mother | Veins carry deoxygenated blood with exception of pulmonary veins which carry oxygenated blood from lungs to heart . |
| The root artery is the Aorta | The largest veins are the venae cavae |
| Valves are absent in arteries . | Valves are present in arteries to prevent backward blood flow . |
| Arteries have thick muscular walls . | Veins have thin non-elastic walls. |
| Blood flows under high pressure . | Blood flows under low pressure . |