UPDATED: The abdominal aorta is the fourth, last, and most distal portion of the aorta. It begins when the descending aorta passes through the aortic hiatus of the respiratory diaphragm, just about the level of the 11th or 12th thoracic vertebra. It ends inferiorly at the bifurcation of the aorta, anterior to the lower portion of the body of the 4th lumbar vertebra where the abdominal aorta is continuous with the right and left common iliac arteries.
The abdominal aorta gives off a number of paired (bilateral) and unpaired (single) arterial branches. The paired branches are:
• Inferior phrenic arteries: provide blood supply to the respiratory diaphragm
The unpaired arterial branches of the abdominal aorta are:
• Celiac trunk: Provides blood supply to the stomach, spleen, liver, and duodenum
Abdominal aorta- Anterior view. Click on the image for a larger version.
|Clinically, the abdominal aorta is divided by the origin of the renal arteries into a suprarenal and an infrarenal segment. This division is important for the surgical treatment of abdominal aortic aneurysms (AAA). To see a AAA, click here.
The suprarenal segment is bound laterally by the crura of the respiratory diaphragm. and its inferior boundary is the superior aspect of the highest renal artery (usually the left renal artery). It has branches that are critical for the blood supply of most of the digestive tract, the celiac trunk and the superior mesenteric artery, plus the inferior phrenic arteries and the suprarenal arteries.
The infrarenal segment includes the renal arteries, the inferior mesenteric artery, gonadal arteries, lumbar arteries, and the middle sacral artery.