norax 



Its branches are : the comes nervi phrenici, to the diaphraj 



mediastinal ; pericardial ; ster- 

 nal ; anterior intercostal, two to 

 each of the six upper spaces, to 

 anastomose with the aortic inter- 

 costals, and many perforating 

 branches which pass through 

 the pectoralis major for the 

 breast and the integument. 



The inusculo-phrenic, the 

 outer of the terminal divisions, 

 slopes behind the sternal ends 

 of the lower spaces, under cover 

 of the diaphragm (which it sup- 

 plies), and gives off anterior 

 intercostals, like those described 

 above. 



The inner division, the supe- 

 rior epigastric, passes through 

 the xiphoid gap in the diaphragm 

 (p. i 52) to enter the rectus ab- 

 dominis, in which it descends 

 to anastomose with the deep 

 epigastric of the external iliac. 

 A twig or two from it enter the 

 falciform ligament to anasto- 

 mose with branches of the hepa- 

 tic artery. 



The internal mammary veins 

 end in the innominate veins. 



Xiigation of the internal 

 mammary in its continuity may 

 be required when an oblique 

 wound, such as a stab, implicates 

 the trunk behind a costal carti- 

 lage, so that the surgeon cannot 

 secure it at the bleeding spot. 

 It may be reached by making a 

 two-inch incision from the side 

 of the sternum through the 

 middle of one of the higher 

 spaces. The skin, fascia:, and 

 pectoralis major having been 

 traversed, the aponeurosis is 

 seen which continues the exter- 

 nal intercostal muscle to the sternum. Then comes the internal inter- 



