The human circulatory system consists of a network of arteries, veins, and capillaries, with the heart pumping blood through it.
- Arteries are blood vessels that transport oxygenated blood from the heart to various parts of the body. They are thick, elastic and are divided into a small network of blood vessels called capillaries. The only exception to this is the pulmonary arteries, which carries deoxygenated blood to the lungs.
- Veins are blood vessels that carry deoxygenated blood towards the heart from various parts of the body. They are thin, elastic and are present closer to the surface of the skin. However, pulmonary and umbilical veins are the only veins that carry oxygenated blood in the entire body.