ARTICULATIONS OF THE CARPUS. 



101 



transverse bands ; as well as by small interosseous ligaments at the 

 upper part of the contiguous surfaces. 



The pisiform bone is articulated to the front of the pyramidal by 

 a distinct raptnh and synorial sac. It has further two special liga- 

 ments ; one of these is attached to the process of the unciform, and 

 the other to the base of the fifth metacarpal bone. 



The BONES OF THE SECOND ROW (fig. 43) are connected together 

 in the same way as those of the first, viz., by a dorsal (i) and a 

 palmar band of fibres from one bone to another. Between the con- 

 tiguous rough surfaces of 

 the several bones are in- 

 terosseous ligaments, one in 

 each interval. 



Movement. Only a small 

 degree of gliding motion 

 is permitted between the 

 different carpal bones of 

 each row, in consequence 

 of the flattened articular 

 surfaces, and the short 

 ligaments uniting one to 

 another ; and this is less 

 in the second than in the 

 first row. 



ONE ROW WITH ANOTHER 



(transverse carpal joint ; FIG. 43. ARTICULATIONS OF THE CARPAL 



BONES, THE JOINT BETWEEN THE Two 

 Rows BEING OPENED BEHIND. 



Separate 

 ligaments of 

 pisiform 

 bone. 



Second row 

 is like first. 



a. Scaphoid bone. 



b. Semilunar. 



c. Pyramidal. 



d. Dorsal trans- 

 verse hands between 

 those bones. 



e. Trapezium. 



f. Trapezoid. 



g. Os magnum. 

 h. Unciform. 



i. Dorsal trans- 

 verse bands joining 

 the bones. 



Tc. External lateral 

 ligament of the inter- 

 carpal joint. 



I. Internal lateral 

 ligament. 



p. Anterior liga- 

 ment. 



anterior, 



fig. 43). The two rows 

 of carpal bones are con- 

 nected by an anterior and 

 posterior, and two lateral 

 ligaments. 



The anterior ligament ( p) 

 consists of strong fibres, 

 which for the most part 

 converge from the three 

 bones of the first row to 

 the os magnum. The 



posterior ligament is thinner and looser ; and its strongest fibres posterior, 

 are transverse. 



Of the lateral ligaments the external (k) is the better marked, and 

 extends between the trapezium and scaphoid bones ; the internal (I) 

 passes from the pyramidal to the unciform bone. 



Dissection. After the division of the lateral and posterior liga- 

 ments, the one row of bones may be separated far enough from the 

 other to allow the articular surfaces to be seen. 



Articular surfaces. The three bones of the first row, viz., 

 scaphoid (), semilunar (6), and pyramidal (c), together form an 

 arch with its concavity turned downwards, while externally the 

 scaphoid presents a convexity to the second row. The lower arti- 

 cular surface has a corresponding form, the os magnum and unciform 



and lateral 

 ligaments. 



Dissection. 



Form of 

 joint-sur- 

 faces. 



