HISTOLOGY
BLOOD VESSELS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Carry blood from the heart towards the body tissues
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Always carry deoxygenated blood
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Contain valves which prevent black flow
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Have thick, muscular walls
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Detailed explanation-1: -Veins have valves to ensure blood flows only towards the heart. Hence, statement C is correct. The one-way valves in veins prevent the blood from flowing backward & and help to force the blood to move towards the heart.
Detailed explanation-2: -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-3: -Medium and large veins have venous valves, similar to the semilunar valves associated with the heart, that help keep the blood flowing toward the heart. Venous valves are especially important in the arms and legs, where they prevent the backflow of blood in response to the pull of gravity.