l8o A MANUAL OF ANATOMY 



scapular nerve passes backwards beneath the ligament, and the 

 suprascapular artery over it, whilst the posterior belly of the 

 omo-hyoid arises from its inner part and from the adjacent 

 portion of the superior border. The internal or vertebral border 

 is known as the base. It is the longest, intermediate in thickness, 

 and extends from the superior to the inferior angle. It is 

 convex, and is divisible into three parts. One part represents 

 the base of the small triangular surface by which the spine 

 arises from the vertebral border, and it gives insertion to the 

 rhomboideus minor ; another extends from this to the superior 

 angle, and gives insertion to the levator anguli scapulae ; and the 

 third extends downwards to the inferior angle, and gives insertion 

 to the rhomboideus major. On the ventral aspect close to this 

 border there is a long narrow linear impression, which widens 

 towards the superior and inferior angles, and gives insertion to 

 the serratus magnus. The external or axillary border, which is the 

 thickest and intermediate in length, extends from the inferior 

 angle to the lower margin of the glenoid cavity. Below that 

 cavity it presents a rough impression, an inch long, called the infra- 

 glenoid ridge, which gives origin to the long head of the triceps, 

 and a little below this a groove for the dorsalis scapulae artery, 

 which also marks the dorsal aspect. The ventral aspect of the 

 bone close to this border presents a" groove over the upper two- 

 thirds, which gives origin to many fibres of the subscapularis. 



The angles are superior, inferior, and external. The superior 

 angle, which is thin, is situated at the meeting of the superior 

 and vertebral borders, and it forms the highest part of the body, 

 being on a level with the second rib. Its ventral aspect gives 

 insertion to a part of the serratus magnus, and its edge to a portion 

 of the levator anguli scapulae. The inferior angle, somewhat thick 

 and round, is situated at the meeting of the vertebral and axillary 

 borders, and it forms the lowest part of the bone, being on a level 

 with the seventh rib. Its ventral aspect gives insertion to a part 

 of the serratus magnus, and its dorsal aspect gives- origin to a 

 portion of the teres major. Below the impression for the latter 

 muscle there is sometimes a rough semilunar marking for a slip of 

 origin of the latissimus dorsi. The external angle, which is massive, 

 is situated at the upper end of the axillary border. It forms the 

 head of the bone, and supports the glenoid cavity, which articulates 

 with the head of the humerus. 



The glenoid cavity, so named from its shallowness, is pyriform, 

 with the narrow end upwards, and its direction is outwards and 

 forwards. Its margin is slightly elevated and rough for the glenoid 

 ligament, and immediately outside the margin the capsular ligament 

 of the shoulder- joint is attached. Superiorly it presents a small 

 rough elevation, called the supraglenoid tubercle, which gives origin 

 to the long head of the biceps. The neck is the constricted portion 

 which extends from the suprascapular notch to a point immediately 

 above the infraglenoid ridge, and it is most evident posteriorly, 



