Overview of aortic aneurysms and aortic dissection

[Dave Paprocki]

The aorta, which is about 1 inch (2.5 centimeters) in diameter, is the largest artery of the body. It receives oxygen-rich blood from the left ventricle and distributes it to all of the body except the lungs (which receive blood from the right ventricle). Just after the aorta leaves the heart, smaller arteries that carry blood to the head and arms branch off. The aorta then arches down, with additional smaller arteries branching off along its route from the left ventricle to the lower abdomen at the top of the hipbone (pelvis). At this point, the aorta divides into the two iliac arteries, which supply blood to the legs.
Disorders of the aorta include

Aneurysms: Bulges in weak areas of the walls of the aorta
Dissection: Separation of the layers of the wall of the aorta

These disorders can be immediately fatal, but they usually take years to develop.
Aneurysms also can develop in other arteries of the trunk, arms, and legs (called peripheral arteries), such as the arteries at the back of the knee (popliteal arteries) and the main arteries of the thighs (femoral arteries). The arteries supplying the head (carotid arteries), the arteries supplying the brain (cerebral arteries), and the arteries supplying the heart muscle (coronary arteries) may also develop aneurysms.
A ruptured aneurysm in the brain may cause subarachnoid hemorrhage.