aorta

The principle artery in humans, the aorta brings oxygen-rich blood to all other arteries except those of the lungs. The aorta begins at the left ventricle of the heart and supplies O first to the heart, then the head and arms followed by the torso/waist...from here the aorta enters the abdomen via the aortic hiatus and feeds blood to your guts before dividing into the two iliac arteries and traveling down your legs.

The lining of the aorta is elastic.

This is the large artery arising from the left ventricle of the heart, in which blood flows from the heart to the body. The most common medical problem of the aorta is atherosclerosis.

The aorta is has three main sections:

1. aortic arch
   
   The part of the aorta between the ascending and descending portions which supplies blood flow to the arms, head and neck through the carotid and subclavian arteries.
   
   
2. ascending aorta
   
   The part of the aorta between the top of the left ventricle of the heart and the aortic arch. The ascending aorta supplies blood to the myocardium (middle layer of the heart wall) through the coronary arteries.
   
   
3. descending aorta
   
   The part of the aorta after the aortic arch which branches into the thoracic and abdominal aortas.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.

A*or"ta (#), n. [NL., fr. Gr. , fr. to lift, heave.] Anat.

The great artery which carries the blood from the heart to all parts of the body except the lungs; the main trunk of the arterial system.

⇒ In fishes and the early stages of all higher vertebrates the aorta divides near its origin into several branches (the aortic arches) which pass in pairs round the esophagus and unite to form the systemic aorta. One or more pairs of these arches persist in amphibia and reptiles, but only one arch in birds and mammals, this being on the right side in the former, and on the left in the latter.

<-- Illustration: heart and aorta -->

© Webster 1913.