Question

In order for blood to always flow unidirectionally through a closed circulatory system, the ________. A. blood vessels farthest from the heart must have valves B. capillaries must have a thick endothelium C. arteries must be elastic D. pressure in all vessels must be equal

Answer 1

The blood vessels farthest from the heart must have valves.

The valves which are present in the blood vessels prevent the backflow of the blood back into the specific organ.

There are different valves present in the heart are:

• The tricuspid valve is situated between the right atrium and right ventricle.
• The pulmonary valve is between the right ventricle and the pulmonary artery.
• The mitral valve is between the left atrium and left ventricle.
• The aortic valve is between the left ventricle and the aorta.

Other vales which are present in the blood vessels are in leg. Leg veins do require the valves. If not present the blood will go back down into the feet because of the gravity. Thus there are various valves present in the leg veins.

Valves in veins are bicuspid, meaning they have two flap-like structures that regulate blood flow in the vein.

To know more about the Valves, refer to this link:

brainly.com/question/12926213

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