AP BIOLOGY

Detailed explanation-1: -Elastic arteries are those nearest the heart (aorta and pulmonary arteries) that contain much more elastic tissue in the tunica media than muscular arteries. This feature of the elastic arteries allows them to maintain a relatively constant pressure gradient despite the constant pumping action of the heart.

Detailed explanation-2: -Blood in arteries flow under high pressure. Therefore, they have and elastic walls.

Detailed explanation-3: -The Aorta. Due to position as the first part of the systemic circulatory system closest to the heart and the resultant high pressures it will experience, the aorta is perhaps the most elastic artery, featuring an incredibly thick tunica media rich in elastic filaments.

Detailed explanation-4: -The pulmonary arteries have thin distensible walls with less elastic tissue than the systemic arteries.