238 



THE A R TIC I 'LA TIOXS 



The three palmar ligaments are stronger than the dorsal, and are deeply placed 

 beneath the mass of extensor tendons; they extend transversely between the bones 

 in a similar manner to the dorsal ligaments. 



The two interosseous ligaments are situated on either side of the magnum, 

 which they connect with the trapezoid on the outer, and the unciform on the inner, 

 side. That between the magnum and trapezoid is attached to the apposed surfaces 

 near their dorsal, i.e. the posterior aspect. That between the magnum and unci- 

 form (tig. 235) is attached to the apposed surfaces at their lower and anterior, i.e. 

 their palmar aspect. 



The synovial membrane is a prolongation of that lining the medio-carpal joint. 



Tlie arterial and nerve-supplies are the same as for the medio-carpal joint. ■ 



(c) Thk Medio-carpal Joixt, or the Union of the Two Rows of the Carpus 



WITH each other 



(I) Class. — Diarthrosis. Subdivision. — Arthrodia. 

 (II) Class. — Diarthrosis. Subdivision. — Condylarthrosis. 



The inferior surfaces of the bones of the first row are adapted to the superior 

 articular surfaces of the bones of the second roAV. The line of this articulation is 

 concavo-convex from side to side, and is sometimes described as having the course 



Fig. 234.— Posterior View of Wrist, with Capsule cut to show Articular Surfaces. 



Transverse dorsal ligament 



Lower end of interosseous 

 ligament 



Inferior oblique ligament 



Triangular fibro-cartilage 

 - Band of posterior ligament of 

 ■wrist left to keep bones in 

 situ 



Tendon Hexor carpi ulnaris 



of a Roman S placed horizontally (/), a resem])lance by no means strained, (i) 

 The outer j)art of the first row consists of tlie scajjhoid alone; it is convex, and bears 

 the trapezium and trapezoid, (ii) Then follows a transversely elongated socket 

 formed by tlie inner part of the scaphoid, the semilunar and cuneiform, into which 

 are received (a) the head of the magnum, Avhich articulates with the scajihoid 

 and semilunar; (b) the upper and outer angle of the unciform, which articulates 

 Avith the semilunar; and (c) the upper convex portion of the internal surface of 

 the unciform, which articulates Avith the external and concave portion of the inferior 

 surface of the cuneif(^rm. (iii) The innermost part of the inferior surface of the 

 cuneiform bone is convex, and turned a little backwards to fit into the lower portion 

 of the internal surface of the unciform, Avhich is a little concave and turned for- 

 Avards to receive it. Tlie central part, Avhich forms a socket for the magnum and 



