PATHOLOGY MCQ
BLOOD VESSELS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Capillaries are really thin so substances like oxygen, carbon dioxide and glucose can move in and out of the vessel. How thick are they?
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Roughly the same thickness of a hair
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One cell thick
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1 Micrometres
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5 Micrometres
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Explanation:
Detailed explanation-1: -Most capillaries are only about 8 to 10 micrometers in diameter (a micrometer is 0.001 mm).
Detailed explanation-2: -The walls of capillaries are just one cell thick. Capillaries therefore allow molecules to diffuse across the capillary walls. This exchange of molecules is not possible across the walls of other types of blood vessel because the walls are too thick.
Detailed explanation-3: -Capillaries have a very thin walls. The main function of capillaries is to transport digested food, oxygen, and other materials to all the cells of the body. Hence, their walls are thin, so that the substances can get in and out of them easily by diffusion.
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