The aorta is an elastic artery. Elastic arteries have elastic tissue mixed through their tunica media. Elastic arteries are also known as conducting arteries because they are located close to the heart and their job is to receive large amounts of blood. When the heart contracts, elastic arteries expand with blood. The elastic tissue then recoils and propels the blood through the circulatory system. Because elastic arteries don't need to control blood flow, they do not have as much muscle as muscular arteries. Because elastic arteries are so thick, they often have smaller blood vessels called vasa vasorum in their tunica externa. The vasa vasorum provide the connective tissue and muscular tissue with blood since these arteries are too thick for oxygen to diffuse all the way through.
These pictures were taken by me in the spring of 2021. They progress from scanning power (40x) to high power (400x). Go through the pictures. Select one, draw it, and label the layers.
