276 



HUMAN ANATOMY. 



the opened joint ; on the outside, the fibres can be traced for a considerable distance 

 from the joint before they are lost in the periosteum. Fibres going to the tuberosi- 

 ties blend with the tendons of insertion of the muscles of the scapular group, the 

 supra- and infraspinati, the teres minor, and the subscapularis, which materially 

 strengthen the capsule. The latter is thinnest behind. 



Certain accessory ligaments strengthen the capsule. The most important is 

 the coraco-hianeral (Fig. 289), which, arising from the outer edge of the horizontal 

 portion of the coracoid where a bursa separates it from the capsule, soon fuses with 

 the latter and runs, without very distinct borders, to both tuberosities, crossing the 

 bicipital groove. A few transverse fibres (the transverse humeral ligament^ bridge 

 in the bicipital groove below the capsule proper. Thr^e: gleno- humeral bands (Fig. 

 290) are described on the inside of the capsule, of which the most important is the 



Tendon of subscapularis and capsule 



Fig. 291. 



Lesser tuberosity 



Tehdon of biceps in bicipital groove 



Glenoid ligament 



Glencfid cavity 



Glenoid ligament 



Greater tuberosity 



Subdeltoid bursa 



Tendon of infraspinatus 

 and capsule 



Horizontal frozen section through the right shoulder-joint from above. 



superior. This band springs from near the top of the inner border of the glenoid 

 cavity and is inserted into the lesser tuberosity. In a part of its course it makes a 

 prominent fold of the synovial membrane along the inner border of the tendon of 

 the long head of the biceps. This ligament has been described as a deep part of the 

 coraco-humeral. The middle ligament is ill-defined. The inferior, running from 

 the lower end of the glenoid socket to the inner side of the neck of the humerus, 

 may be seen both from without and within the capsule. It is made tense when the 

 arm is abducted, and materially strengthens the joint. The capsule usually presents 

 an opening on the inner side in the upper part, by which the bursa below the tendon 

 of the subscapularis communicates with the joint. The cases in which the capsule 



