The three kinds of blood vessels of human circulatory system are arteries, veins and capillaries. Their functions are as follows:
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Arteries |
Veins |
Capillaries |
1. |
Carry Oxygen rich blood from heart to all parts of the body.
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Carry carbon di oxide rich blood from all parts of the body back to the heart.
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Capillaries act as a link between arteries and veins.
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2. |
Since blood flow is rapid and at high pressure they have thick elastic walls.
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They have thin walls
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Consists of just a single layer of endothelial cells. Water and other small-molecule substances can pass through this wall.
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3. |
Valves are absent.
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Valves present to prevent back flow of blood.
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No valves are found
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