136 



ARTHROLOGY. 



bone by a piece of fibro-cartilage. The i^roxhnal inierhyoid 

 articulation is also amphiarthrodial, a similar cartilage joining the 

 cornu and corniculum ; the latter articulates with the hyoid bone 

 by a true synovial joint, the distal interhyoid. 



In the proximal interhyoid cartilage a small ossicle may be 

 found, which in ruminants appears as a second corniculum. The 

 motion in the two first-named joints is considerable. We may 

 mention here that the heel processes are attached at their ends 

 to the thyroid cartilage of the larynx by the lateral hyo-thyroid 

 ligaments, between which is found the middle ligament {see 

 " Laryngeal Ligaments "). 



Articulations of the Appendicular Skeleton, 

 pectoral ldib. 



the shoulder JOINT. 



The Scajndo-humeral articulation is formed by the glenoid 

 cavity of the scapula, and the articular head 

 of the humerus. It is a ball-and-socket 

 joint, with one strong capsular ligament. 

 The bones are held in position by the follow- 

 ing muscles which pass from the shoulder- 

 blade to the arm, and play the part of 

 active ligaments : — The antea spinatus, 

 postea spinatus, postea spinatus minor, sub- 

 scapularis, and flexor brachii. The motion 

 of the joint is angular, lateral, and circum- 

 ductive. 



THE ELBOW JOINT. 



The Humero-radio-ulnar is a ginglymus 

 formed by the radius, ulna, and humerus. 

 It has capsular and lateral ligaments. The 

 capsular is strongest in front, where it 

 stretches from the distal end of the humerus 

 to the head of the radius ; posteriorly it 

 encloses the articulation of the ulna with the 

 humerus, and it also surrounds the double 

 articulation between the head of the ulna and 

 the radius. Anteriorly it is attached to the 

 brachii, posteriorly to that of the anconeus 



Fig. 51. 

 Ligaments of the elbow 

 joint — posterior view. a. 

 External lateral ligament ; 

 h, Internal lateral ligament ; 

 c, External, and d, Internal 

 arciform ligaments. 



tendon of the fl 



exor 



