How can arteries contract and expand?
Artery walls are composed of elastic tissue and smooth muscle which allows them to contract and expand.
Arteries and arterioles conduct blood away from the heart. As the heart pumps, blood passes through these vessels which contract and expand to maintain an even pressure during each pulsation of the heart
Artery walls are comprised of many different layers, of which the most important are the elastic tissue layers and the smooth (involuntary) muscle layers. These layers allow for the regular contraction and expansion of arteries and arterioles that functions both to maintain a regular blood pressure as well as to continue the blood flow from the heart.