The Circulatory System - Blood Vessels 0.0 / 5 ? BiologyCirculationGCSEEdexcel Created by: joshdCreated on: 26-03-14 17:13 What do the arteries do? These carry the blood away from the heart. 1 of 15 What do the capillaries do? These are involved in the exchange of materials with the tissues. 2 of 15 What do the veins do? These carry the blood to the heart. 3 of 15 What does the heart pump, so what are the artery walls like? The heart pumps the blood out at high pressure, so the artery walls are strong and elastic. 4 of 15 What are the walls thick compared to? What do they contain? The walls are thick compared to the size of the hole down the middle (the lumen). They contain thick layers of muscle to make them strong. 5 of 15 What do arteries branch into? Capillaries. 6 of 15 Describe the size of capillaries They are really tiny - too small to see. 7 of 15 What do capillaries do? (in detail) They carry the blood really close to every cell in the body to exchange substances with them. 8 of 15 What do capillaries have? They have permeable walls, so substances can diffuse in and out. 9 of 15 What do capillaries supply? What do they take away? They supply food and oxygen, and take away wastes like CO2. 10 of 15 What are capillaries walls usually only? What does this mean? Their walls are usually only one cell thick. This increases the rate of diffusion by decreasing the distance over which it occurs. 11 of 15 What do capillaries eventually join up to form? Veins. 12 of 15 Where is the blood at lower pressure and what does this mean? The blood is at lower pressure in the veins, so the walls don't need to be as thick as artery walls. 13 of 15 What do veins have bigger than the arteries? They have a bigger lumen than arteries to help the blood flow despite the low pressure. 14 of 15 What do veins also have and what do they do? They also have valves to help keep the blood flowing in the right direction. 15 of 15
Bio 3 - Transportation of Substances around the Body - The circulatory system 4.5 / 5 based on 4 ratings
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