3. Arteries have a thick elastic muscle layer, whereas the muscle layer for veins is much thinner. This is because the heart pumps blood into the arteries at high pressures, so the walls of the arteries must be able to cope with the changes in pressure during a heartbeat. Veins carry blood at much lower pressures so do not need such a thick ...

Veins, on the other hand, have a thinner tunica externa (the tough outside layer) because the blood pressure within the vein is less than the blood pressure in the artery. They have a thinner muscular layer which means there is less contraction and the blood travels at a lower pressure. Like arteries, veins have a thin layer of endothelium.

5. Arteries have a thick inner layer of circular elastic and muscle fibres, to help pump the blood on after every heartbeat, whereas veins have thin layers with relatively few circular elastic and muscle fibres, as blood does not flow in pulses so the wall of the veins cannot help to pump it. Functional differences. 1.

Arteries have to carry oxygenated blood away from the heart to the tissues at high pressure. Small lumen (relative to the large, muscular vessel) ensure this pressure is maintained as the blood is transported around the body. Veins carry unoxygenated blood towards the heart, away from tissues at low pressure so the lumen is large.

2. Veins have one-way valves whereas arteries do not have any valves.Veins need valves as the blood flowing through them is at such a low pressure that they need something to prevent it going backwards! They are needed to prevent blood pooling. Arteries do not need valves as the blood is flowing at such a high pressure that it cannot go backwards.

Veins. Veins carry blood from tissues back to the heart . You can remember this as veins carry blood into the heart. Because the blood in veins has already travelled a long distance from the heart, it is much lower pressure blood than is carried in arteries. This means that veins don't need the same structure as arteries.

Arteries carry blood away from the heart to the rest of the body and veins then take blood back to the heart. Because the heart directly pumps blood into the arteries by its forceful contractions, arteries carry blood at a much higher pressure relative to veins and therefore are structurally adapted very differently to veins.

Arteries, veins and capillaries are all types of blood vessels. The best way to think about their differences are the roles they play in circulation. So, if we take the systemic circulation as an example (that is the circulation from the heart to the body and back to the heart) we can look at the key features of each vessel.

They have thin walls, with large lumens. They also contain valves, to prevent backflow of blood. Arteries transport oxygenated blood, except for the pulmonary artery, while veins transport deoxygenated blood, except for the pulmonary vein.• Capillaries are very small blood vessels that connect arteries to veins. Capillaries are the site of ...

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.