Blood circulates through arteries, capillaries and veins. Veins have valves, but arteries do not. Explain why.
Answers
Answer:
Unlike arteries, veins contain valves that ensure blood flows in only one direction. (Arteries don't require valves because pressure from the heart is so strong that blood is only able to flow in one direction.) Valves also help blood travel back to the heart against the force of gravity.
Answer:
here is the answer
Explanation:
The main function of the valves in veins is to prevent back flow of blood.
Blood in the arteries, after being pumped by the heart, are under much higher pressure than blood in veins so there is no need for valves in arteries to prevent back flow.
Blood in veins is under much lower pressure as it is returning to the heart from the various organs and tissues and so has a risk of back flow if the valves are not present to prevent it.