320 



THE ARTICULATIONS, OR JOINTS 



The dorsal ligaments (ligamenta basium oss. metacarp. dorsalia) and palmar 

 ligaments (ligamenta basium oss. metacarp. volaria) pass transversely from one 

 bone to another on the dorsal and palmar surfaces. 



The interosseous ligaments (ligamenta basium oss. metacarp. interossea) pass 

 between their contiguous surfaces, just beneath their lateral articular facets. 



Synovial Membrane (Fig. 256). The synovial membrane between the lateral facets is a 

 reflection from that between the two rows of carpal bones. 



TENDON OF FLEXOR 

 SUBLIMIS DIGITORUM 



TENDON OF FLEXOR 

 PROFUNDUS DIGITORUM 



LATERAL 

 LIGAMENT 



TRANSVERSE 



METACARPAL 



LIGAMENT 



SECOND LUM- 

 BRICAL MUSCLE 



ANTERIOR OR SECOND 



VAGINAL LIGAMENT PALMAR 



INTEROSSEOUS 

 MUSCLE 



TRANSVERSE META- 

 CARPAL LIGAMENT 



ANTERIOR OR 

 VAGINAL LIGAMENT 



FIG. 257. Metacarpal bones and first phalanges of the second to the fifth finger of the right hand, with 

 ligaments, from the volar surface. (Spalteholz.) 



The transverse metacarpal ligament (ligamentum capitulorum oss. metacar- 

 palium transversum) (Fig. 257) is a narrow, fibrous band which passes trans- 

 versely across the anterior surfaces of the digital extremities of the four inner 

 metacarpal bones, connecting them. It is blended anteriorly with the palmar 

 ligaments of the metacarpophalangeal articulations. To its posterior border is 

 connected the fascia which covers the Interossei muscles. Its anterior surface is 

 concave where the Flexor tendons pass over it. Behind it the tendons of the 

 Interossei muscles pass to their insertion. 



X. Metacarpophalangeal Articulations (Articulationes Metacarpophalangeae) 



(Figs. 257, 258). 



These articulations are of the condyloid variety, formed by the reception of 

 the rounded head of the metacarpal bone into a shallow cavity in the extremity 

 of the first phalanx. The expansion of the Extensor communis digitorum tendon 



