CARPAL BONES. 295 



1. ARTICULATIONS OF THE FIRST Eow OF CARPAL BONES. 



These are arthrodial joints. The articular surfaces are covered with cartilage, 

 and connected together by the following ligaments : 



Two Dorsal. Two Palmar. 



Two Interosseous. 



The two Dorsal Ligaments are placed transversely behind the bones of the 

 first row; they connect the scaphoid and semilunar, and the semilunar and 

 cuneiform. 



The two Palmar Ligaments connect the scaphoid and semilunar, and the semi- 

 lunar and cuneiform bones; they are less strong than the dorsal, and placed 

 very deep under the anterior ligament of the wrist. 



The two Interosseous Ligaments (Fig. 203) are two narrow bundles of fibrous 

 tissue, connecting the semilunar bone, on one side with the scaphoid, on the 

 other with the cuneiform. They close the upper part of the interspaces between 

 the scaphoid, semilunar, and cuneiform bones, their upper surfaces being 

 smooth, and lined by the synovial membrane of the wrist-joint. 



The articulation of the pisiform with the cuneiform is provided with a sepa- 

 rate synovial membrane, protected by a thin capsular ligament. There are also 

 two strong fibrous fasciculi, which connect this bone to the unciform, and base 

 of the fifth metacarpal bone (Fig. 201). 



2. ARTICULATIONS OF THE SECOND Eow OF CARPAL BONES. 



These are also arthrodial joints. The articular surfaces are covered with 

 cartilage, and connected by the following ligaments : 



Three Dorsal. Three Palmar. 



Two Interosseous. 



The three Dorsal Ligaments extend transversely from one bone to another on 

 the dorsal surface, connecting the trapezium with the trapezoid, the trapezoid 

 with the os magnum, and the os magnum with the unciform. 



The three Palmar Ligaments have a similar arrangement on the palmar surface. 



The two Interosseous Ligaments, much thicker than those of the first row, are 

 placed one on each side of the os magnum, connecting it with the trapezoid 

 externally, and the unciform internally. The former is less distinct than the 

 latter. 



3. ARTICULATIONS OF THE Two Eows OF CARPAL BONES WITH EACH OTHER. 



The articulations between the two rows of the carpus consist of a joint in the 

 middle, formed by the reception of the head of the os magnum into a cavity 

 formed by the scaphoid and semilunar bones, and of an arthrodial joint on each 

 side, the outer one formed by the articulation of the scaphoid with the trape- 

 zium and trapezoid, the internal one by the articulation of the cuneiform and 

 unciform. The articular surfaces are covered by a thin layer of cartilage, and 

 connected by the following ligaments : 



Anterior or Palmar. External Lateral. 



Posterior or Dorsal. Internal Lateral. 



The Anterior or Palmar Ligaments consist of short fibres, which pass ob- 

 liquely between the bones of the first and second row on the palmar surface. 



The Posterior or Dorsal Ligaments have a similar arrangement on the dorsal 

 surface of the carpus. 



The Lateral Ligaments are very short ; they are placed, one on the radial, 

 the other on the ulnar side of the carpus ; the former, the stronger and more 

 distinct, connecting the scaphoid and trapezium bones, the latter the cunei- 



