PATHOLOGY MCQ
BLOOD VESSELS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Precapillary sphincters will
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control blood flow into the true capillaries
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cause blood to flow from the precapillary arteriole
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open when the tissue needs nutrients
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close when the tissue has low O2
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close when tissues have low CO2
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Explanation:
Detailed explanation-1: -high oxygen, low carbon dioxide and high pH cause smooth muscle cells in arterioles and precapillary sphincters to contract, decreasing local blood flow.
Detailed explanation-2: -Local physical factors acting on the vascular smooth muscle, such as changing blood volume and blood pressure, also act as autoregulatory stimuli that affect arterioles. Decreased blood pressure will cause precapillary sphincters to open, allowing more blood to reach the capillary bed.
There is 1 question to complete.