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4 Cards in this Set
- Front
- Back
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What are the three different types of blood vessels and their jobs?
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Arteries, carry blood away from the heart
Capillaries, involved in the exchange of materials in tissues Veins, carry blood back to the heart |
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What are the properties of arteries?
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The heart pumps blood out at high pressure so the artery walls are strong and elastic. The walls are thick compared to the small lumen. They have thick layers of muscle to make them strong and elastic fibres to allow them to stretch and spring back.
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What are the properties of capillaries?
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Arteries branch capillaries. Capillaries are very small. They carry blood very close to every cell in the body to exchange substances with them. They have permeable walls so substances can diffuse in and out. They supply food and oxygen and remove waste like carbon dioxide. They are usually only one cell thick, increasing the rate of diffusion by decreasing the distance over which it occurs.
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What are the properties of veins?
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Capillaries eventually join up to form veins. The blood is at lower pressure so the walls do not need to be as thick as artery walls. They have a large lumen to help blood to flow despite the lower blood pressure. They also have valves to help keep the blood flowing in the right direction.
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