PATHOLOGY MCQ
BLOOD VESSELS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Veins have valves that prevent blood from falling backwards.Why would this happen if there were no valves?One, some or all answers could be correct?
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Blood is much heavier in veins
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Blood in veins is at a lower pressure
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Gravity is in the opposite direction to the flow of blood
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Blood is much thicker in veins
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Explanation:
Detailed explanation-1: -The blood passing through the veins is deoxygenated (except in pulmonary veins) and flows at a low pressure. It flows slow and steady against the direction of gravity. Therefore, veins have valves to prevent the backflow of blood.
Detailed explanation-2: -The one-way valves in deep veins prevent blood from flowing backward. The muscles surrounding the deep veins squeeze the veins, helping force the blood toward the heart, just as squeezing a toothpaste tube ejects toothpaste.
Detailed explanation-3: -Veins have valves which stop the blood from flowing backward. This is because blood pressure in veins is very low (compared to arteries).
There is 1 question to complete.