THE METACARPALS 



165 



articulation with the base of the first phalanx. The volar surface is grooved for 

 the flexor tendons and raised on each side into an articular eminence. On each 

 side of the head is a prominent tubercle, and immediately in front of this a well- 

 marked fossa, to both of which the collateral ligament of the metacarpo-phalangeal 

 joint is attached. 



Fig. 199. — The Second (Left) Metacarpal. 



Radial side 



For greater multangular 



Ulnar side 



For third metacarpal 

 For capitate 



The second is the longest of all the metacarpal bones, and the third, fourth, 

 and fifth successively decrease in length. The several metacarpals possess dis- 

 tinctive characters by which they are readily identified. 



The first metacarpal (fig. 198) is the shortest and widest of the series. Diverging from the 

 carpus more widely than any of the others the palmar surface is directed medially and marked 



Fig. 200. — The Third (Left) Metacarpal. 



Radial side 



For second metacarpal 



Ulnar side 



For fourth metacarpal 



Styloid process 



b}- a ridge placed nearer to the medial border. The lateral portion of the surface slopes gently 

 to the lateral border and gives attachment to the opponens pollicis; the medial portion, the 

 smaller of the two, slopes more abruptly to the medial border, is in relation to the deep head of 

 the flexor pollicis brevis, and presents the nutrient foramen, directed downward toward the 

 head of the bone and transmitting a branch of the arteria princeps pollicis. The dorsal 

 surface, •^vide and flattened, is in relation to the tendons of the extensor pollicis longus and brevis. 



