324 



HUMAN ANATOMY 



tendons and their sheaths. It is strong at the sides ; weak in front and behind. 

 The stronger bands are inextricably blended with the rest ; that on the outside, the 

 external lateral ligament,^ runs from the radial styloid process to the outer side of 

 the scaphoid, thence to the trapezium, and is continuous with the capsule of the 

 carpo-metacarpal joint of the thumb. The internal lateral ligament' runs from the 

 styloid process of the ulna to the side of the cuneiform, and to the pisiform, thence 

 to the narrow internal edge of the unciform, and finally to the fifth metacarpal. The 

 dorsal part of the capsule is the weakest, but is much strengthened by the extensor 

 tendons. A continuous layer passes from the radius and ulna to the first row, thence 

 to the second, and thence to the metacarpals. The general direction of the fibres of 



Fig. 343. 



Radius Interosseous membrane Ulna 



Tubercle of scaphoid 



Ridge of trapezium 

 Anterior carpal ligament 



Outer end of ant. annular ligament 



Styloid process 

 Radio-carpal ligament 



Ant. inferior radio-ulnar 

 ligament 



Styloid process 



Pisiform ligament 



Pisiform 



Int. lateral ligament 

 Unciform 



Tendon of ext. carpi 

 ulnaris 



Inner end of ant. annular ligament 



Anterior aspect of right wrist-joint. A portion of the anterior annular ligament has been riemoved and the canal for 



the flexor carpi radialis opened. , 



the proximal part is transverse, inclining inward from the styloid process of the radius 

 and the scaphoid to the cuneiform. This constitutes the dorsal transverse ligavient, 

 which serves to hold the head of the os magnum and the adjoining part of the unci- 

 form in the socket made by the concavity of the first row. It has no definite borders. 

 Tolerably distinct bands pass to the bases of the four inner metacarpals ; those to 

 the second and third are tense and the others lax. Various accessory bands are 

 often found. The a^iterior part of the capsule in the hollow of the wrist is stronger : 

 it is reinforced by oblique bands converging downward. Many of these fibres are 

 attached to the narrow palmar prominence of the os magnum. Pretty distinct 

 bundles go to the bases of the metacarpals. Very small disks project into both the 

 radio-carpal and the intracarpal joints from the dorsum, which are hardly seen except 



'Lig. coUaterale carpi radiale. -Lig. coUaterale carpi ulnare. 



