412 FASCIA. 



attachments to the several ridges on- the back of the radius and 

 of the ulna, form the Ligamentum Carpi Dorsale. This liga- 

 ment is extended from the styloid or outer margin of the radius, 

 transversely to the styloid or inner margin of the ulna, to the 

 pisiform bone, and to the fifth metacarpal. It consists, in some 

 measure, of two portions: of which the superior is the smaller 

 and thinner, has its fibres descending from the radius to the ulna, 

 and is crossed, in part, by the fibres of the inferior or greater 

 portion. As this ligament adheres, with great strength, to the 

 ridges on the back of the bones of the fore arm, six trochleae for 

 the tendons of the extensor muscles are thus formed. The first, 

 or that next to the styloid process of the radius, contains the 

 tendons of the first two extensors of the thumb. The second is 

 'larger, and transmits the tendons of the two radial extensors of 

 the carpus. The third is small and oblique, for the tendon of 

 the third extensor of the thumb. The fourth is the largest, and 

 is for the tendons of the extensor communis of the fingers. The 

 fifth is between the radius and the head of the ulna, and is for 

 that tendon of the extensor communis which goes to the little 

 finger. The sixth is on the back of the ulna, and is for the ten- 

 don of the extensor carpi ulnaris. 



The inferior margin of this dorsal ligament of the wrist does 

 not terminate abruptly, but resuming its fascia-like character, 

 is continued over the back of the wrist, and over that of the 

 hand to the fingers. In this progress it furnishes an envelope 

 to the extensor tendons, and is very much blended with the ob- 

 lique fasciculi, by which they communicate with each other. 



The Fascia Brachialis affords origin, in part, to the muscles 

 on the dorsum of the scapula below its spine; on the arm it is 

 not so intimately connected with the muscles, but on the fore 

 arm they again begin to arise, in part, from it. In its whole 

 course partitions, constituting the sheaths of the rriuscles, and 

 which consist, for the most part, of common cellular and adipose 

 membrane, go from it down to the periosteum and interosseous 

 ligament. It adheres very tightly to the ulna, from the ole- 

 cranon to the styloid process. On its cutaneous surface are 

 found all the superficial veins, nerves, and lymphatics of the 

 arm. Bichat considers this membrane as the best example of 



