What is the difference between an artery and a vein?
Arteries are thick walled vessels which carry oxygenated blood from the heart to the body. Veins are thin walled vessels which carry de-oxygenated blood from the body back to the heart to be re-circulated. There is a third kind of vessel, called lymphatic vessels which are tiny, extremely delicate vessels that carry proteins and lymphatic fluid from the body back to the heart.
