OF THE CARPUS. 217 



tion, adduction, and circumduction. ' It is totally incapable of rotation, one of the 

 characteristic movements in true enarthrodial joints. 



8. ARTICULATIONS OF THE CAEPUS. 

 These articulations may be subdivided into three sets : 



1. The articulation of the first row of carpal bones. 



2. The articulation of the second row of carpal bones. 



3. The articulation of the two rows with each other. 



1. ARTICULATION 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 Dorsal Ligaments, two in number, are placed transversely behind the 

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

 and cuneiform. 



The Palmar Ligaments, also two in number, connect the scaphoid and semi- 

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

 and placed very deep under the anterior ligament of the wrist. 



The Interosseous Ligaments (fig. 135) 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 syuovial membrane of the wrist-joint. 



The articulation of the pisiform with the cuneiform is provided with a separate 

 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. 



2. ARTICULATION OF THE SECOND Eow OF CARPAL BONES. 



These are 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 exter- 

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



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



The articulation between the two rows of the carpus consists of an enarthrodial 

 joint in the middle, formed by the reception 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 trapezium 

 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. 



