All about the heart and blood vessels! The heart 5.0 / 5 based on 2 ratings ? BiologyHuman, animal and plant physiologyASEdexcel Created by: smudgeacornCreated on: 04-04-14 17:00 What does the pulmonary artery do? Pump deoxygenated blood to the lungs 1 of 19 What does the pulmonary vein do? brings oxygenated blood back from the lungs 2 of 19 What do the cords in the heart do? attach the atrioventricular valves to the ventricles to stop them being forced up into the atria when the ventricles contract 3 of 19 Why do the ventricles have thicker walls than the atria? because they have to push blood out of the heart, whereas the atria just need to push blood a short distance to the ventricles 4 of 19 Why does the left ventricle have thicker walls than the right ventricle? needs to contract powerfully to pump blood all the way round the body but right side only needs to get blood to the lungs, which are nearby 5 of 19 What does the vena cava do? bring deoxygenated blood back from the body 6 of 19 If there is higher pressure behind a valve, is it forced open or shut? open 7 of 19 If there is higher pressure in front of a valve, is it forced open or shut? shut 8 of 19 Why do arteries have elastic tissue in the walls? to cope with the high pressure caused by the heartbeat 9 of 19 Why is the endothelium in the artery folded? to allow the artery to expand, helping it to cope with high pressure 10 of 19 Do arteries have thick or thin muscle layer? Thick 11 of 19 Do veins have a thick or thin muscle wall? Thin 12 of 19 Do veins contain valves? Yes 13 of 19 Do arteries contain valves? No 14 of 19 How is blood helped to flow through veins? by contraction of body muscles surrounding them 15 of 19 Are veins elastic? No 16 of 19 Which has a larger lumen - arteries or veins? veins 17 of 19 What are the networks of capillaries in tissues called? Capillary beds 18 of 19 Why are capillary walls (endothelium) only one cell thick? To speed up diffusion 19 of 19
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