74 THE POCKET ANATOMY 



2ND PART. Extent. From superior to inferior border oi 

 pectoralis minor. 



Relations. In front. Pectorales major and minor. 

 Behind. Subscapularis, posterior cord of plexus. 

 Outer side. Outer cord of plexus. 

 Inner side. Inner cord of plexus, separating artery from 



3RD PART. Extent. From inferior border of pectoralis 

 minor to lower border of teres major. 



Relations. In front. Pectoralis major, inner head of median 

 and internal cutaneous nerves ; below, skin and fasciae. 



Behind. Subscapularis, tendons of latissimus dorsi and 

 teres major, musculo-spiral and circumflex nerves. 



Inner side. Uln'ar nerve, axillary vein, and lesser internal 

 cutaneous nerve. 



Outer side. Coraco - brachialis, median and musculo- 

 cutaneous nerves. 



Branches : 



Superior thoracic (ist part) : arises opposite ist intercostal 

 space, supplies pectorales ; anas, internal mammary, inter- 

 costals. 



Acromio-thoracic (ist part) : arises from front of artery 

 just above pectoralis minor. 



Branches : 



Acromial : supply and perforate deltoid; anas, branch of 

 supra-scapular and posterior circumflex. 



Humeral : accompanies cephalic vein ; anas, anterior 

 circumflex. 



Thoracic : two or three branches to supply side of thorax ; 

 anas, intercostal, 



Clavicular : one or two twigs to clavicle and subclavius. 



Long thoracic (and part) : passes downwards along inferior 

 border of pectoralis minor to about 6th intercostal space, 

 supplies pectorales and serratus magnus ; anas, intercostal 

 and other thoracic branches. In female gives branches to 

 mammary gland : external mammary. 



Alar thoracic (and part) : supplies glands and fat of the 

 axilla ; not a constant separate branch. 



Subscapular (3rd part) : arises opposite lower border of 

 Subscapularis muscle, and courses with the long subscapular 

 nerve to lower angle of scapula. 



Branch : 



Dorsalis scapula : given off near origin to dorsum of scapula, 

 passes backwards to the infraspinous fossa through triangular 



