932 



A MANUAL OF ANATOMY 



internal mammary. It arises from that vessel in the sixth inter- 

 costal space, and passes obliquely downwards and outwards behind 

 the seventh, eighth, and ninth costal cartilages. About the level 

 of the tenth rib it perforates the diaphragm and terminates in the 

 lateral wall of the abdomen, where it anastomoses with the lateral 

 epigastric branch (ascending branch) of the deep circumflex iliac 

 artery. It gives off anterior intercostal and muscular branches. 

 The anterior intercostal arteries are two in number to each of the 

 seventh, eighth, and ninth intercostal spaces, in which they are 



Sterno-hyoid Muscle 

 Sterno-thyroid Muscle 



Subclavian Artery (First Part) 



Internal Mammary 

 Artery 



Anterior Intercostal 

 Arteries 



Sternal Glands 



Superior 



Epigastric 



Artery 



Musculo-phrenic Artery 



Fi&. 382. 



-Dissection of the Anterior Wall of the Thorax 

 (Posterior View). 



disposed in a manner similar to the anterior intercostal branches of 

 the internal mammary. The muscular branches are distributed to 

 the diaphragm and lateral wall of the abdomen. In the diaphragm 

 they anastomose with the inferior phrenic branch of the abdominal 

 aorta and the superior phrenic branch of the internal mammary. 



The superior epigastric artery is the other terminal branch of the 

 internal mammary, of which it is the continuation. It descends 

 behind the seventh costal cartilage, and passes through the areolar 

 interval between the sternal and costal portions of the diaphragm 



