MEDICAL
HEART AND PERICARDIUM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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There is no blood pressure in a vein. Therefore, veins require valves to prevent the backflow of blood?
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True
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False
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Either A or B
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None of the above
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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 valves prevent the backward flow of blood. Valves are actually flaps (leaflets) that act as one-way inlets for blood coming into a ventricle and one-way outlets for blood leaving a ventricle. Normal valves have 3 flaps (leaflets), except the mitral valve. It only has 2 flaps.
Detailed explanation-3: -Because the pressure is low, veins possess valves to prevent backflow and stop the blood from pooling at the lowest extremities.
There is 1 question to complete.