AP BIOLOGY

Detailed explanation-1: -Thick walls of arteries help them to resist the pressure of the flow of blood in them. Elastic walls of arteries: The elastic layer allows stretching and absorbs pressure. The walls stretch and recoil in response to pumping, thus peaks in pressure are absorbed.

Detailed explanation-2: -Veins have thick, elastic and muscular walls.

Detailed explanation-3: -Arteries and arterioles have relatively thick muscular walls because blood pressure in them is high and because they must adjust their diameter to maintain blood pressure and to control blood flow.

Detailed explanation-4: -Since the blood pumped from the heart into the arteries flows at higher pressure than the blood in veins, hence arteries need to have thicker walls or else the high blood pressure might cause them to burst.

Detailed explanation-5: -Compared to other blood vessels, arteries have thick walls and are located superficially. This is mainly because these blood vessels perform the critical function of carrying oxygenated blood throughout the body under considerable pressure.