Outline the differences between arteries and veins? (6) marks- 3 for each

Arteries and veins are the "tubes" that carry blood around the body.Artieries have thick outer walls in order to cope with the blood passing through being under such high pressure generated by the heart. Arteries also have thick layers of muscle and elastic fibres. Arteries carry blood away from the heart and the majority contain oxygenated blood, except from a few examples such as the pulmonary artery which contains deoxygenated blood. In contrast, veins carry blood towards the heart. They have thin walls and also thin layers of muscle and elastic fibres. Unlike arteries, veins have one way valves to keep the blood moving in the correct direction.Most veins contain deoxygenated blood apart from a few examples, such as the pulmonary veins.