The aorta, the largest artery in the body, carries blood from the
heart to the rest of the body.
The aorta rises out of the left ventricle of the heart (the ascending
aorta) and then curves down like an upside-down U (aortic arch). It passes
through the chest cavity and the abdomen, ending where it branches into the
iliac arteries, which provide blood to the pelvis and legs. Multiple branches
come off the
aorta throughout its course to supply blood to the various organs
in its proximity.
The aorta, like all blood vessels, requires nutrients and oxygen for
its survival. Blood vessels are constantly being injured and repaired,
absorbing and secreting nutrients and chemicals through junctions in their
Physicians classify the aorta and its branches based on their
location within the body. The thoracic aorta is the portion of the aorta in the
chest (or thorax), which includes the ascending portion, the arch, and the
descending portion of the aorta. This section feeds blood vessels in virtually
every structure in the upper body, including the brain, arms, lungs, and
The abdominal aorta is the portion of the aorta that passes through
the diaphragm into the abdomen. This section feeds blood vessels to the
abdominal organs (stomach, liver, spleen, pancreas, kidneys, and bowel). The
abdominal aorta eventually branches into the iliac arteries, which provide
blood to the pelvis and legs.
The wall of the aorta contains three layers: the intima, media, and
adventitia. The layers have significance both in the aorta's function and the
pathology that is found when a disease process interferes with the makeup of
- The intima is made up of cells that line the
blood vessel (endothelial cells), creating a smooth surface for the blood flow.
This prevents clots (thrombi) from forming along the surface.
media is made up of smooth muscle cells that are flexible, allowing the aorta
to expand and contract. It is this layer that provides the muscle and strength
to the wall of the artery.
- The adventitia provides more strength
to the vessel.