THE AXILLARY ARTERY. 239 



which it runs to anastomose at the inferior angle 

 with the subscapular. 



The Internal Mammary. Runs along the poste- 

 rior surface of the anterior wall of the chest and sends 

 off: 



Phrenic. Accompanies the phrenic nerve. 



Anterior Costal. Five to seven branches to inter- 

 costal spaces. 



Mediastinal. To anterior mediastinum. 



Pericardiac. To outer surface of pericardium. 



Perforating. Perforate the intercostal spaces and 

 are distributed to the mammary gland. 



Sternal. Nutrient to sternum. 



Muscular. To intercostals and triangularis sterni. 



Superior Epigastric. Anastomoses with deep epi- 

 gastric of the external iliac. 



Superior Intercostal. Distributed to the two upper 

 intercostal spaces. It sends off the profunda cervicis to 

 anastomose with the princeps cervicis of the occipital. 



THE AXILLARY ARTERY. 



The axillary artery is the continuation of the sub- 

 clavian ; it begins at the lower border of the first rib and 

 becomes the brachial at the lower border of the pectoralis 

 major muscle. It runs midway between the anterior and 

 posterior borders of the axilla and is crossed by the pec- 

 toralis minor muscle, which divides it into three parts ; 

 from the first part above the pectoralis minor are given 

 off two vessels : 



Superior Thoracic. Passes inward and supplies 

 ,the muscles of the chest. 



Acromio-thoracic. A short trunk which divides into 

 the acromial, distributed to the shoulder, and the thoracic, 

 to the pectoral muscles. 



