76 Anatomy of Skeleton 



in the recent state is deepened and enlarged by the glenoid ligament and by the fact 

 that the cartilage lining it is thinnest centrally. The capsule is fastened to the outside 

 of the rim and to the outside of the glenoid ligament, so that synovial membrane 

 passes off this last on to the capsule with only a slight furrow intervening. 



At the top, however, this arrangement is somewhat modified : the glenoid liga- 

 ment not only joins the Biceps tendon, but is continued on the rim below it, and the 

 capsule is attached in front of and behind the Biceps, passing up to become continuous 

 with the coraco-humeral ligament on the coracoid process immediately above it. 



Coracoid Process (Fig. 57). 



This has already been described as arching forwards and a little outwards from 

 the upper border of the bone over the tendon of Subscapularis : its tip is slightly 

 depressed, showing a tendency to turn down in front of this muscle. We find, therefore, 

 that its under surface is smooth and concave for the play of the tendon, from which 

 it is separated by a subcoracoid bursa. Its other surfaces are roughened by the 

 attachment of ligaments and tendons. Its upper surface ends behind in the rounded 

 conoid tubercle from which the trapezoid ridge runs forwards along the outer part of 

 the surface : in front of these is the slightly marked roughness for Pectoralis minor, 

 on the inner border and upper surface. The acromial branch of the acromio-thoracic 

 axis crosses the process between the ligaments and the insertion of the tendon, under 

 cover of the Deltoid. The costo-coracoid membrane, on which this artery lies at first, 

 is attached to the inner part of the upper surface between the ligaments and the 

 insertion of Pectoralis minor. On the inner aspect are seen part of the attachment 

 of this muscle and of the conoid ligament. 



Looked at from the outer side a well-marked ridge is visible running forward 

 toward the end of the process and lying immediately outside and below the trapezoid 

 ridge. This outer edge shows two more or less definite markings, one near its posterior 

 end (Fig. 57, 4) and a larger one near the front extremity, for the two main bands of 

 the coraco-acromial ligament : between these the ridge affords attachment to the very 

 weak central portion of the ligament, which is frequently absent. 



Just below the level of the edge and the coraco-acromial ligament is the area of 

 attachment of the coraco-humeral ligament, the apex of which extends far enough 

 forward to lie under cover of the anterior coraco-acromial band : the area widens 

 behind and externally to enclose the supraglenoid tubercle (where the Biceps has 

 origin for its long tendon), and becomes continuous on each side of this with the 

 capsular marking. 



Whatever may be the comparative value of the coracoid process, there is no doubt that it is 

 one of the primary parts of the bone, and is concerned in the formation of a part of the glenoid fossa, 

 as already shown in Fig. 58. The portion that aids in forming the cavity is ossified from a distinct 

 centre, which, from its occurrence before the true epiphyses, probably is also of primary value. 

 This and the main centre for the process join, and are afterwards furnished with small epiphyses 

 on the prominent tubercles. The coracoid element (ventral) is separated from the scapular or 

 dorsal element before fusion along the dark green line A in Fig. 57, which passes through the notch 

 on the rim of the glenoid as well as on the front wall of the suprascapular notch. 



The suprascapular notch is bounded in front by the base of the coracoid process, 

 to which the bands of the suprascapular ligament are therefore attached : these bands 

 may be two in number, an upper stronger part bridging the notch and attached to its 

 margins and dorsal sides of these margins, and a lower weaker and more ventrally 

 situated band. Under the lower band runs a vein passing up from the subscapular 

 fossa to join the suprascapular vessels, while the nerve and one of the venae comites of 

 the suprascapular artery pass between the two bands. 



