100 



THE BONES OF THE UPPER LIMB. 



THE CABPUS. 



The carpus is composed of eight short bones, which are disposed in two rows, 

 four in each. Enumerated from the radial to the ulnar side, the bones which con- 

 stitute the first or superior row are named scaphoid, lunar, pyramidal, and pisiform / 

 those of the second or inferior row are the trapezium, trapezoid, os magnum, and 

 unciform. 



The dorsal surface of the carpus is convex, the palmar is concave from side to 

 side, the concavity being bounded by four prominences, one at the outer and one at 



Fig. 99. THE BONES OF THE RIGHT HAND: A, FROM BEFORE; B, FROM BEHIND. (Allen Thomson. ) ^ 



s, scaphoid ; I, lunar ; c, pyramidal ; p, pisiform ; t, trapezium ; next to it the trapezoid, and then 

 the os magnum, both not lettered ; u, unciform . 



I to V, the metacarpal bones ; 1, 3, first and second phalanges of the thumb ; 1, 2, 3, the first, 

 second, and third phalanges of the little finger, and similarly for the other three fingers, not marked ; 

 * one of the sesamoid bones of the thumb seen sideways. 



the inner extremity of each row. The anterior annular ligament is stretched across 

 between these prominences, so far as to form a canal for the transmission of the 

 flexor tendons. 



The superior surfaces of the scaphoid, lunar, and pyramidal bones form, when in 

 apposition, a continuous convexity which corresponds with the concavity presented 



Fig. 100. SEMI-DIAGRAMMATIC VIEW OF THE RIGHT CARPUS 



AND PART OF THE METACARPAL BONES, FROM BEFORE, 

 THE CARPAL BONES BEING SLIGHTLY SEPARATED TO SHOW 

 THE MODE OF THEIR CONNECTION WITH EACH OTHER. 



(Allen Thomson. ) f 



1, scaphoid bone; 2, lunar; 3, pyramidal ; 4, pisiform; 

 5, trapezium, the figure is placed upon the ridge, to the 

 inside of which is the groove for the tendon of the flexor 

 carpi radial is; 6, trapezoid; 7, os magnum; 8, unciform, 

 the figure is placed on the unciform process. The articula- 

 tion of the fourth metacarpal bone with the os magnum is 

 represented somewhat too large. 



by the radius and the triangular fibre-cartilage, while the pisiform bone is attached 

 in front of the pyramidal, with which alone it articulates. The line of articulation 

 between the superior and inferior rows is concavo-convex from side to side, the 



