602 



ANGIOLOGY 



behind the trachea and the esophagus, and may anastomose with the highest 

 right intercostal artery. It represents the remains of the right dorsal aorta, and in a 

 small proportion of cases is enlarged to form the first part of the right subclavian 

 artery. 



The Abdominal Aorta (Aorta Abdominalis) (Fig. 531). 



The abdominal aorta begins at the aortic hiatus of the diaphragm, in front 

 of the lower border of the body of the last thoracic vertebra, and, descending in 



Inferior phrenic arteries 





Internal 



spermatic 



vessels 



FIG. 531. The abdominal aorta and its banohes. 



front of the vertebral column, ends on the body of the fourth lumbar vertebra, 

 commonly a little to the left of the middle line, 1 by dividing into the two common 

 iliac arteries. It diminishes rapidly in size, in consequence of the many large 

 branches which it gives off. As it lies upon the bodies of the vertebrae, the curve 

 which it describes is convex forward, the summit of the convexity corresponding 

 to the third lumbar vertebra. 



1 Lord Lister, having accurately examined 30 bodies in order to ascertain the exact point of termination of this 

 vessel, found it "either absolutely, or almost absolutely, mesial in 15, while in 13 it deviated more or less to the left, 

 and in 2 was slightly to the right. " System of Surgery, edited by T. Holmes, 2d ed., v, 652. 



