blood flows at a high pressure, so if the arteries are thin and less muscular, the arteries can explode due to the pressure. so it needs thick and muscular properties so that it can withstand the increasing pressure of the flow of blood.
im not sure why it needs to be elastic. Hope it helped :)
Answer:
Excretion helps maintain Homeostasis by excreting wastes from the body, which eliminates harmful toxins housing themselves in your body, which would increase the chance of getting an illness. ... When you exhale, carbon dioxide and some water are removed from the body by the lungs.
Vein because they have valves to prevent back flow of blood.
Through the atmosphere and through <span>oceanic conveyer belts that act as physical pumps</span>
