THE CARPUS 



129 



The Scaphoid 



This is the largest bone of the proximal row. Its superior surface is somewhat 

 triangular and convex for articulation with the lower end and styloid process of the 

 radius. Its inferior surface has two facets: a large one for the trapezium, and a 

 small one for the trapezoid. The dorsal surface is occupied by a long, deep 

 groove for ligaments. The palmar surface is rough and concave above; below, it 

 has a prominent tuberosity for the attachment of the anterior annular ligament and 



Extensor carpi 

 radialis lougior 



Extensor carpi 

 radialis brevier 



Extensor primi 

 internodii pollieis 



Ext. secundi 

 interaodii _ 

 pollieis 



Fio. 134.— The Left Haxd. (Dorsal surface.) 



SEMILUNAR 

 SCAPHOID^ 



jl^^^^tV"! S I F o R n 



UNCIFORM 



TRAPEZIUM 



Extensor carpi ulnaris 



Extensor communis digitorura 



Extensor communis digitorum 



THIRD, UNGUAL, OR TERMINAL PHALANX 



the abductor p()lllcls muscle. The outer (radial) surface is rough for ligaments. 

 The inner (ulnar) surface is occu})ied by two articular facets, of which the ujiper 

 one is crescentic in sha])e for the semilunar bone, Avlnlst the lower is deeply concave 

 for the reception of tlu- head of the magnum. 



Articulations. — \\'ith radius, trapezium, trapezoid, magnum, and semilunar. 



The Semilunar 



The semilunar has a convex superior surface for articulation with the lower 

 end of the radius and the tibro-cartilage of the wrist. Its inferior surface is 

 9 



