298 



ARTICULATIONS. 



X. METACARPO-PHALANGEAL ARTICULATIONS. (Fia. 204.) 



These articulations are of tbe ginglymus kind, formed by the reception of 

 the rounded head of the raetacarpal bone, into a superficial cavity in the extre- 

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



Anterior. Two Lateral. 



The Anterior Ligaments (Glenoid ligaments of Cruveilhier) are thick dense 



... ^ , and fibro-cartilaginous in tex- 



Fig. 204.-Articulat 10 ns of the Phalanges. - 



LATERAL LIGAMENT 



Metacarpa - pJitda, ngeal 

 Art ie 7 



ture. Each is placed on the 

 palmar surface of the joint, in 

 the interval between the late- 

 ral ligaments, to which they 

 are connected ; they are loose- 

 ly united to the metacarpal 

 bone, but very firmly to the 

 base of the first phalanges. 

 Their palmar surface is in- 

 timately blended with the 

 transverse ligament, forming 

 a groove for the passage of 

 the flexor tendons, the sheath 

 surrounding which is con- 

 nected to each side of the 

 groove. By their internal 

 surface, they form part of the 

 articular surface for the head 

 of the metacarpal bone, and 

 are lined by a synovial mem- 

 brane. 



The tivo 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 extre- 

 mity 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, adduction, abduction, and 

 c.ircumduction ; the lateral movements are very limited. 



XL ARTICULATIONS OF THE PHALANGES. 



' These are ginglymus joints, connected by the following ligaments : 

 Anterior. Two Lateral. 



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

 phalangeal 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 



Arti 



