146 



BONES OF THE CAEPUS. 



Fig. 155. 

 I ll in 



Fig. 156. 



Lower surface. 1 



IV. Upper surface. 



Fig. 157. 



VI VII 



VIII 



Fig. 158. 



VIII VII VI 



or disease, we learn the amount of importance they confer 

 upon the hand. 



[ 2/4. The HAND consists of the CAEPUS, METACAEPUS, 

 and PHALANGES; of these, part of the carpus (fig. 154 A), with 

 the radius, form the wrist joint ; the metacarpus (B) forms the 

 palm of the hand, and the phalanges (c) the fingers. 



[ 275. The CAEPUS consists of eight bones, forming an 



arch, (figs. 155 

 158), the concavity 

 of which is placed be- 

 fore, and the con- 

 vexity behind. These 

 eight bones are ar- 

 ranged in two rows, 

 four in each row; 

 there are, in the first row (figs. 155, 156), on the outside the os 

 scaphoides (i), on its inner side the os lunare (n), next it the os 

 cuneiforme (in), and on the front of that bone the os pisiforme 

 (iv) : in the second row (figs. 157, 158), on the outside is the 



os trapezium 

 (v), next to it 

 the os trape- 

 zoides (YI), to 

 its inner side, 

 the os mag- 

 num (vn), 

 and next to 



that the os unciforme (vm). Of these bones the first row is 

 articulated above with the radius, and the interarticular car- 

 tilage at the extremity of the ulna, and below with the second 

 row ; the second row articulates above with the first row, and 

 below with the bases of the metacarpal bones. 



[ 276. The METACAEPUS consists of five bones (fig. 158*), 

 each of which is divided into its upper part, or basis (A) ; 

 middle or body, corpus (B) ; and lower part or head, caput (c), 

 which forms the knuckle, and projects when the fingers are 

 bent. Upon the bases are articular surfaces for the carpal 

 bones. 



[ 277. The thumb and fingers of each hand consist of four- 

 teen pieces, or phalanges (fig. 159) ; of these twelve belong to 

 the fingers, and are disposed in three rows, those of the middle 

 finger (in) being longest, and of the little finger (v) shortest ; 



Lower surface. 



Upper surface. 



