Vessels 0.0 / 5 ? BiologyHealth, illness and diseaseASEdexcel Created by: hannahmurrayCreated on: 20-04-14 19:14 Arteries Narrow lumen, thicker walls, more collagen, elastic fibres and smooth muscle, no valves. 1 of 5 Veins Wide lumen, thinner walls, less collagen, elastic fibres and smooth muscle, valves present. 2 of 5 Walls of arteries and veins Collagen, a tough fibrous protein; strong and durable, elastic fibres; stretch and recoil, smooth muscle; constrict and dilate. 3 of 5 Blood through Vessels Systole(contracts) blood forced into arteries, elastic walls stretch. Diastole(relaxation) walls recoil to push blood forward. Blood reaches arteries and capillaries> steady flow. 4 of 5 Capillaries Join arteries and veins, very narrow, walls on 5 of 5
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