Notes

The arteries and veins differ in structure because the arteries because it has different functions. The walls of arteries are thicker than the walls of veins becasue the arteries becasue the arteries carry blood away from the body so, it has to be able to endure high pressure. The veins however have valves, but the arteries don't. The valves prevent the blood from going the opposite direction. The blood is helped in numerous different ways on it return back to the heart. One example of it this is when the muscles around the veins contract and help push blood through the veins back to the heart since veins do not contract. Also, as mentioned earlier, the valves prevent the blood from flowing backwards. Varicose veins are twisted, enlarged veins usually in the legs since theres a lot of pressure put on the lower body from walking, standing, and more. They appear twisted and bulged usually blue or purple in color. Most of the time, it is benign and just more of a cosmetic issue, but sometimes they can lead to more serious problems. THe varicose veins form because the valves in the veins that should prevent blood from flowing backwards are not working as they should. The increased amount of blood in the vein pushes against the vein walls, which may already be weak, and the vein gets bigger. Varicose arteries don't form because they do not have valves and nonexisting valves cant malfunction. So since the blood doesnt flow bakcwards, the arteries cant stretch like varicose veins do. Also, the arteries are much stronger than veins since the walls are thicker and dont streetch as easily.