AXILLARY ARTERY. BRANCHES. 323 



The relations of the axillary artery may be thus arranged: 



In Front. Inner or Thoracic Side. Outer or Humeral Side. 



Pectoralis major, First intercostal muscle, Plexus of nerves, 



Pectoralis minor, First serration of ser- Tendon of sub- 

 Pectoralis major. ratus magnus, scapularis, 



Plexus of nerves. Coraco-brachialis. 



Branches. The branches of the Axillary artery are seven in 

 number: 



Thoracica acromialis, 

 Superior thoracic, 

 Inferior thoracic, 

 Thoracica axillaris, 

 Subscapular, 

 Circumflex anterior, 

 Circumflex posterior. 



The thoracica acromialis and superior thoracic are found in the tri- 

 angular space above the pectoralis minor. The inferior thoracic and 

 thoracica axillaris, below the pectoralis minor. And the three re- 

 maining branches below the lower border of the subscapularis. 



The Thoracica acromialis is a short trunk which ascends to the space 

 above the pectoralis minor muscle, and divides into three branches, 

 thoracic, which is distributed to the pectoral muscles and mammary 

 gland ; acromial, which passes outwards to the acromion, and inoscu- 

 lates with branches of the supra-scapular artery ; and descending, 

 which follows the interspace between the deltoid and pectoralis major 

 muscles, and is in relation with the cephalic vein. 



The Superior thoracic (short) frequently arises by a common trunk 

 with the preceding ; it runs along the upper border of the pectoralis 

 minor, and is distributed to the pectoral muscles and mammary gland, 

 inosculating with the intercostal and mammary arteries. 



The Inferior thoracic (long external mammary) descends along the 

 lower border of the pectoralis minor to the side of the chest. It is 

 distributed to the pectoralis major and minor, serratus magnus, and 

 subscapularis muscle, to the axillary glands and mammary gland ; 

 inosculating with the superior thoracic, intercostal, and mammary 

 arteries. 



The Thoracica axillaris is a small branch distributed to the plexus 

 of nerves and glands in the axilla. It is frequently derived from one 

 of the other thoracic branches. 



The Subscapular artery, the largest of the branches of the axillary, 

 runs along the lower border of the subscapularis muscle, to the inferior 

 angle of the scapula, where it inosculates with the posterior scapular, 

 a branch of the subclavian. It supplies, in its course, the muscles on 

 the under surface and inferior border of the scapula, and the side of the 



