Arteries carry blood away from the heart. They carry rich oxygenated blood towards the body. This blood is under high pressure as it is being pumped along by the heart every time it beats. In order for arteries to withstand this pressure they have special design features. Arteries have thick muscular walls which contain elastic fibres that allow the artery to stretch under pressure. The muscle fibres also contract to push the blood along and keep it flowing. In addition the narrow lumen maintains a high pressure and ensures the blood flows quickly to all parts of the body. The contracting of the arteries can be felt in your body as a pulse, for example at your wrist or neck.