Question

Why doesn't the arteries need valves?
1. Is it because of high pressure . CAN HIGH PRESSURE MAKE THE CELLS MOVE IN FORWARD DIRECTION?
2. So that means that because the cells in the veins dont have much pressure they need valves..

3. But this goes against..this..
" Varicose veins occur when veins are unable to prevent backward flow of blood in places where high blood pressure occurs such as in the feet"

Plz explain while considering my guess.

Thankyou

Answer 1

The main function of the valves in veins is to prevent back flow of blood.
But Blood in the arteries, after being pumped by the heart, are under much higher pressure than blood in veins. Therefore, there is no need for valves in arteries to prevent back flow. same as you said.

=> But in case of varicous veins which most effect our legs. There is high pressure is occurs. But high gravity in legs prevent the blood to flow upward. That is gravity in the legs is more than the pressure in the legs. Then veins are unable to prevent back flow.