The vascular system consists of three groups of vessels — arteries, veins and capillaries.
Why Do Arteries Have Thick Muscular Walls. Because of the increased arterial pressure. Arteries have more smooth muscle in their walls than veins to accommodate the pulses of blood generated by each contraction of the heart.
Why are the walls of arteries thicker than those of veins ... from qph.fs.quoracdn.net
Arterioles have muscular walls that usually consist of one or two layers of smooth muscle. Thick walls of arteries help them to resist the pressure of flow of blood in them. The vascular system consists of three groups of vessels — arteries, veins and capillaries.
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.
The thick muscular walls of arteries allow it to withstand the high pressure from the heart pumping blood through it. Thick walls of arteries help them to resist the pressure of flow of blood in them. Arteries have more smooth muscle in their walls than veins to accommodate the pulses of blood generated by each contraction of the heart. If a muscle does not get any use, the body will eventually break it down to conserve energy.