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

Question

Quizplus · Accepted Answer

Valves are essential for ensuring that blood flows in only one direction in blood vessels farthest from the heart, such as veins, where the blood flow is slower and less pressurized. This prevents backflow and ensures that blood continues to travel towards the heart.

In Order for Blood to Always Flow Unidirectionally Through a Closed