Aorta thoracica. 



215 



Car of is 

 dextra ^ 



J.subciav. 

 dextra, 



A. anon 



^A.transv. 

 colli 



Cos to, L 



A.inlcr. 

 cost, supremo. 

 (Trunc.costo- 

 cervic.) 



M.M. 



in ter- 



coslales 



561. Course and Ramification of the Descending 

 Thoracic Aorta. 



. The origins from the posterior part of the aorta of each two of 

 the intercostal arteries, are nearer to each other, the lower these arteries 

 are placed. Several intercostal arteries may arise from a common trunk, 

 which descends in front of the heads of the ribs. The artery which 

 runs at the lower border of the twelfth rib, should, according to Haller, 

 be more correctly called the first lumbar, Art. lumbalis prima. The 

 upper intercostal arteries frequently arise lower than the position of 

 the intercostal spaces to which they belong. 



