ine 



ARTICFLATIOXS OF THE UPrEn LIMB. 



The two rows of carpal bones arc miitccl by dorsal, palmar, and 

 lateral ligaments. Tlie latfral liijamcnts are placed one at the radial, 

 the other at the ulnar border of the carpus ; the former connects the 

 scaphoid bone with the trapezium, the latter the cuneiform with the 

 uncifonn. The dorsal ligamenis consist of fibres passing in various 

 directions ; the ])almar J///ammfs are chiefly composed of fibres converg- 

 ing towards the cs magnum. 



The bones of the first row, the pisiform bones excepted, are 

 united by interosseous and by dorsal and jialmar ligaments. The 

 mferosseotfs ligaments, placed on the sides of the semilunar bone on a 

 level with its superior surface, connect it with the scaphoid and cunei- 

 form bones, thus completing the inferior wall of the radio-carpal joint. 

 The dorsal and palmar ligaments, each two in number, extend trans- 

 versely on the dorsal and palmar surfaces from the scaphoid bone to the 

 semilunar, and from the semilunar to the cuneiform. 



The bones of the second row are connected by similar means. The 

 dorsal and palmar ligaments, each three in number, pass transversely 

 between the contiguous bones. The interosseous liganwifs are gene- 

 rally three (but sometimes only two) in number, a strong ligament 

 being placed between the os magnum and unciform bones, another 

 l)etween the trapezoid and trapezium, and a slender ligament between 

 the OS magnum and trapezoid. A small interosseous ligament is also 

 sometimes found between the os magnum and the scaphoid. (Fig. 142.) 



The synovial cavity of the carpal articulations is extensive and 

 complicated. Passing between the two rows of carpal bones, it sends 



Fig. 142. Fig. 142. — Transverse Section of the Sy- 



KoviAL Cavities of the Inferior Radio- 

 ulnar, Radio-Carpal, Intercarpal, and 

 Carpo-Metacarpal Articulations. (A. T.) 



1, points to the triangular fibro-cartilage 

 below the ulna ; 2, placed on the nlna, iwints 

 to the cavity of the sacciform synovial mem- 

 brane ; 3, external lateral, and 4, internal 

 lateral ligament, and between them the synovial 

 cavity of the wrist ; 5, scaphoid bone ; 6, semi- 

 lunar ; 7, cuneiform ; 8, 8, upper portion, and 

 S', 8', lower portion of the general synovial 

 cavity of the intercarjial and carpo-metacarpal 

 articulations ; between .5 and 6, and 6 and 7, 

 the interosseous ligaments are seen separating 

 the caqial articidar cavity from the wrist- 

 joint ; between the four carpal bones of the 

 lower row, and between the magnum and 

 scaphoid, the interosseous ligaments are also 

 shown ; the upper division of the synovial 

 cavity communicates with the lower between 

 10 and 11, and between 11 and 12 ; x , marks 

 one of the three interosseous metacarpal liga- 

 ments ; 9', sejiarate synovial cavity of the first 

 cai-]io-metacari)al articulation ; 13, first, and 14, fifth, metacarpal bone. 



Note. It is to be observed that in this figure, and in others of a like kind which 

 represent the joint-cavities, the white or black lines indicating the s\Tiovial membranes 

 are, for the sake of clearness, generally represented as jiassing over the surfaces of the 

 articular cartilages, although this is not the case in nature. These lines therefore must 

 be held to represent merely the whole continuity of the articular, or, as they are often 

 called, the sjTiovial surfaces. 



