DISSECTING MANUAL. 



the upper six intercostal spaces, piercing the Internal inter- 

 costals. Anterior perforating, one branch to each of the upper 

 six interspaces, piercing the Intercostals and Pectoralis major, 

 and accompanying the intercostal nerves; the third and 

 fourth go to the mammary gland. Musculo-phrenic, a branch 

 descending behind the costal cartilages to the Diaphragm and 

 piercing this; besides muscular branches it sends anterior 

 intercostal branches to the seventh, eighth, and ninth inter- 

 spaces. Superior epigastric, piercing the Diaphragm and 

 descending behind and through the Rectus, this gives off the 

 following branches: muscular; anterior cutaneous, piercing 

 the Rectus with the intercostal nerves; ensiform, to that 

 process ; and hepatic, to the falciform ligament. [825] 



Superior Intercostal. This arises from the back of the first 

 (left side) or second (right side) part, arches backward over 

 the pleura and descends in front of the neck of the first rib to 

 the first interspace ; there it divides into two branches, one of 

 which runs outward in each of the first two interspaces, be- 

 tween the Intercostals. A branch (profunda cervicis) arises 

 above the first rib, runs backward below the last cervical trans- 

 verse process, and ascends under the Complexus into the 

 neck. [826] 



Axillary. The thoracic branches are the superior thoracic, 

 to the first interspace; long thoracic, running along the lower 

 border of the Pectoralis major; and the pectoral branch of the 

 acromio-thoracic, which descends between the two pectoral 

 muscles. [827] 



Branches of Descending Thoracic Aorta. Intercostal: 

 These nine pairs of arteries go to the nine lower interspaces, 

 running over the bodies of the vertebrae but under other 

 structures. Each runs in a subcostal groove, with the vein 

 above and nerve below, between the Intercostals. It sends a 

 collateral branch along the lower border of the interspace, a 

 lateral cutaneous branch with the corresponding nerve, and 

 muscular branches to adjacent muscles. A dorsal branch of 



[132] 



