AXILLARY 



523 



(a) The acromial branch or branches pass outwards across the coracoid process, 

 frequently through the deltoid muscle, which they in part supply, to the acromion, 

 where they form, by anastomosing with the anterior and posterior circumflex and 

 suprascapular arteries, the so-called acromial rete, or plexus of vessels on the sur- 

 face of that process. 



(6) The humeral branch — the descending branch of some authors — runs 

 downwards with the cephalic vein in the interval between the pectoralis major and 

 the deltoid, and, supplying lateral offsets to these muscles and the adjacent integu- 

 ments, anastomoses witli the anterior and posterior circumflex arteries. 



(c) The pectoral branch j^asses between the pectoralis major and minor mus- 



Fio. 347. — The Dorsal Scapular Artk:ry, Right Side. 

 (From a ilissectiou in the Museum of the Koyal College of Surgeons.) 



Supra-spinatus Siiprascnjitilar artery 

 Posterior scajnilar artery | | Infra-spinatus 



Rhomboideus minor 

 Levator anguli scapula 



Triceps, cut 



Deltoid, insertion 

 Deltoid 



Trapezius 

 Rhomboideus major 



Teres major muscles 



Teres major, insertion 

 Dorsalis scapulce artery Posterior circumjiez artery 



cles, both of which it supplies, and the superimposed mammary gland. In the 

 female, one or more of these branches which perforate the pectoralis major are often 

 of large size. 



(d) The clavicular branch passes upwards V)eneath the clavicle and supplies 

 the subclavius muscle, and anastomoses with the suprascapular artery. 



Branches of the Second Part of the Axillary Artery 



1. The long thoracic artery — also called the external mammary — descends 

 along the lower l)order nf the pectoralis minor, under cover of tlie ])ect<iralis major, 

 to the walls of the chest. It supplies both pectoral muscles and the serratus 



