50 HUMAN ANATOMY. 



The superior border, shortest, presents : 



Supra-scapular notch at the base of the coracoid process, 

 converted into a foramen [supra-scapular] by the transverse liga- 

 ment, for the passage of the supra-scapular nerve (the artery 

 passing above) ; 



Origin of omo-hyoid muscle from this border just internal 

 to notch. 



External or axillary border, thickest, presents : 



Rough impression, just below glenoid cavity, for origin of 

 long head of triceps muscle, and below, 



FIG. 21. 



1, supra-spinous fossa; 2, infra-spinous fossa; 3, superior border; 

 4, supra-scapular notch; 5, axillary border; 6, head; 7, inferior 

 angle; 8, neck; 9, vertebral border; 10, spine; 11, surface for tra- 

 pezius; 12, acromion process; 13, nutrient foramen; 14, coracoid 

 process. 



Longitudinal groove, for origin of part of subscapularis. 



Internal, vertebral border (base), longest, presents: 



Anterior lip, for insertion of serratus magnus; 



Posterior lip, for attachment above of supra-spinatus, below 

 infra-spinatus. 



The superior angle, gives attachment to part of levator 

 angular scapulas; 



The inferior angle, for attachment of teres major, and some- 

 times part of latissimus dorsi. 



The anterior or external angle is thickest, and forms the 

 head. 



