Abdominal aorta: The abdominal aorta is the final section of the aorta, the largest artery in the body. It is a continuation of the thoracic aorta. It begins at the diaphragm, and runs down to the point where it ends (by splitting in two to form the common iliac arteries).
Like the other sections of the aorta (the ascending aorta, aortic arch and thoracic aorta), the abdominal aorta is an arbitrary anatomic entity. The aorta is one continuous conduit that arises out of the left ventricle of the heart to carry blood to the body. Nonetheless, the abdominal aorta is a hallowed and convenient subdivision of the aorta.
The abdominal aorta is also known in medical Latin as the aorta abdominalis or the pars abdominalis aortae (under which it is often hidden in standard print medical dictionaries).