Arteries

These are blood vessels that carry oxygenated blood away from the heart. They have thick, elastic walls to withstand the high pressure of the blood as it leaves the heart. The artery has three layered walls. The inner layer is lined with cells called endothelium and this is thinner and made up of elastic membrane. The middle layer has smooth muscle and elastic tissue but it is a thick layer. The outer layer is made up of fibrous connective tissue.

The aorta is the largest artery and this carries oxygenated blood directly away from the heart. Arteries have no valves due to the high pressure under which blood is pumped out from them. The blood pumped under the arteries are high in pressure, so the blood passes through the arterioles in order to reduce the pressure in the blood movement before it gets into the capillaries

The arterioles are tiny branches of the arteries which transport blood to the capillaries

The main function of the arteries is to transport blood away from the heart.