The aorta is both the main artery of the body and the largest artery in the body. It acts as the central supply source of oxygenated blood flow throughout the body and plays a large role in circulation. Beginning at the heart's left ventricle, the aorta travels upwards, slightly over and then down through the abdomen, where it branches off into the left and right iliac arteries that run through the legs. The aorta is often referred to in divided sections called the ascending aorta, the aortic arch, the thoracic or descending aorta and the abdominal aorta.

The ascending aorta is the section that goes up directly from the heart. The aortic arch is the part that arches slightly back and over the left lung. As it goes down again through the thorax, it becomes the thoracic, or descending, aorta and then the abdominal aorta before it divides into the iliac arteries. The aorta also branches off into smaller arteries that travel to the neck, the head and the arms, which essentially supply the body's major organs and tissues with oxygenated blood.

Like a network of tunnels that the heart pumps blood into, the aorta acts as the center of blood flow supply and the origin of all other major arteries including the carotid artery and the pulmonary artery. The aortic valve controls the blood flow pumped into the aorta and prevents oxygenated blood from reentering the left ventricle.

Problems with the aorta are often the result of a heart defect at birth, but they can also develop over time. It is not uncommon for the aortic valve to work improperly in newborns and preemies. Sometimes, the heart defect is outgrown and other times, surgical repair is necessary. Narrowing of the aorta and other arteries is not uncommon and is often the cause of poor circulation.