WHY ARTERIES HAVE THICK WALLS.
2.WHY VEINS HAVE THUN WALLS AND WHY THEY HAVE VALVES.
pls ans quickly i have exam on saturday
2. Veins have thin wall because, they bring back blood from different organs to the heart and the blood that travels inside the vein do not have to withstand high pressure unlike arteries, so they possess thin wall.
Veins have valves within them in order to prevent back flow of blood. Blood in the veins flow slowly and with a low pressure so there are chances of backflow.
1 Artries have thick walls as blood flows in pressure, 2 Vein have thin walls as blood does not flow in pressure ,through veins deoxygenated blood returns back to the heart therefore it is not in pressure and so it does not need thick walls. 3 veins carry deoxygenated blood therefore to prevent the backflow of blood valves are present.
Ithink u are inthe same scool as mine Because even i have the same exam on saturday