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ARTICULATIONS. 



Metacarpe -phala. nc/eal 



10. METACARPO-PHALANGEAL AETICULATIONS (fig. 137). 



These articulations are of the ginglymoid kind, formed by the reception of the 

 rounded head of the metacarpal bone, into a superficial cavity in the extremity 

 of the first phalanx. They are connected by the following ligaments : 



Anterior. Two Lateral. 



The Anterior Ligaments are thick, dense, and fibro-cartilaginous in texture. 



Each is placed on the palmar 

 Fig. l37.-Articulations of the Phalanges. surface of the joint, in the 



interval between the lateral 

 ligaments, to which they are 

 connected ; they are loosely 

 united to the metacarpal bone, 

 but very firmly to the base of 

 the first phalanges. Their 

 palmar surface is intimately 

 blended with the transverse 

 ligament, each ligament form- 

 ing with it a groove for the 

 passage of the flexor tendons, 

 the sheath surrounding which 

 is connected to it at each side. 

 By their internal surface, they 

 form part of the articular 

 surface for the head of the 

 metacarpal bone, and are lined 

 by a sy no vial membrane. 



The Lateral Ligaments are 

 strong rounded cords, placed 

 one on each side of the joint, 

 each being attached by one 

 extremity to the tubercle on 

 the side of the head of the 

 metacarpal bone, and by the 

 other to the contiguous ex- 

 tremity of the phalanx. 



The Posterior Ligament is 

 supplied by the extensor ten- 

 don placed over the back of 

 each joint. 



Actions. The movements 

 which occur in these joints 

 are flexion, extension, adduc- 

 tion, abduction, and circumduction ; the lateral movements are very limited. 



11. AETICULATIONS OF THE PHALANGES (fig. 137). 



These are ginglymoid joints, connected by the following ligaments : 

 Anterior. Two Lateral. 



The arrangement of these ligaments is similar to those in the metacarpo-pha- 

 langeal articulations; the extensor tendon supplies the place of a posterior 

 ligament. 



Actions. The only movements permitted in the phalangeal joints are flexion 

 and extension ; these movements are more extensive between the first and second 

 phalanges than between the second and third. The movement of flexion is very 

 extensive, but extension is limited by the anterior and lateral ligaments. 



Artie 



