168 



THE ARTICULATIONS OF THE UPPER LIMB. 



connected with the tendon of the long head of the biceps muscle, which is also 

 attached at the upper end of the glenoid fossa, within the capsule of the joint. 



The synovial membrane is reflected uninterruptedly from the margin of the 

 glenoid cavity on the inner surface of the fibrous capsule to the humerus, but its form 

 is complicated by its relation to the tendons of the biceps and subscapularis muscles. 



Fig. 194. VIEW OF THE GLENOID CAVITY AND LIGAMENTS BETWEEN 



THE SCAPULA AND CLAVICLE OF THE BIGHT SIDE. 3 



1, glenoid fossa, its cartilaginous surface ; 2, glenoid ligament ; 

 3, tendon of the biceps muscle in connection with the upper part of 

 the glenoid ligament ; 4, upper surface of coracoid process ; 5 and 6, 

 on the adjacent part of the clavicle ; 4 to 5, the conoid ; 4 to 6, the 

 trapezoid portion of the coraco-clavicular ligament ; 7, apex of the 

 acroruion process ; 4 to 7, coraco-acromial ligament : 8, acromio- 

 clavicular articulation, which is open anteriorly, showing a wedge- 

 shaped interarticular fibro-cartilage attached above to the superior 

 acromio-clavicular ligament ; x , inferior acromio-clavicular ligament. 



The long tendon of the biceps muscle, traversing the 



joint in its course from the upper end of the glenoid cavity to the bicipital groove, is 

 enclosed in a tubular sheath, formed by a process of the synovial membrane, which 

 is continued down upon it into the osseo-fibrous canal between the tuberosities of the 

 humerus, and is thence reflected upwards lining the canal, to become continuous with 



Fig. 195. A, SECTION THROUGH THE SHOULDER-JOINT, TENDON OF THE BICEPS AND BICIPITAL GROOVE, 



SHOWING SOMEWHAT DIAGRAMMATICALLY THE SYNOVIAL CAVITY OF THE JOINT, &C. (Allen 



Thomson.) 

 B, OUTLINE OF THE SAME, TO SHOW THE REFLECTION OF THE SYNOVIAL MEMBRANE OVER 



THE TENDON. 



1, outer part of the clavicle ; 2, its acromial end ; 3, cavity of the shoulder-joint close to the upper 

 part of the head of the scapula, where there are seen the section of the cartilages on the head of the 

 humerus and in the glenoid cavity, the glenoid ligament and the origin of the tendon of the biceps 

 muscle ; 4, glenoid ligament in the lower part of the cavity ; 5, upper pai't of the capsular ligament and 

 synovial membrane ; 6, tendon of the biceps as it passes out of the joint into the bicipital groove ; 

 6', 6', tubular prolongation of the synovial membrane round the tendon ; 7, reflection of the synovial 

 membrane on the humerus within the lower part of the capsular ligament. 



the synovial membrane of the capsule in such a manner as to preserve the integrity 

 of the membrane. The bursal prolongation of the synovial membrane under the 

 tendon of the subscapularis muscle is of variable extent, sometimes projecting but 

 slightly, sometimes forming a considerable pouch on the venter of the scapula. 



Subacromial bursa. Superficial to the muscles covering the top of the joint 

 is a large bursa, which facilitates the movements of the upper end of the humerus 

 beneath the acromion process, the coraco-acromial ligament, and the deltoid muscle. 



