144 



THE UPPER EXTREMITY 



these are attached to the ridges on the dorsal aspect of the 

 distal end of the radius, so as to form a series of six bridges 



Extensor pollici 



longus 



Extensor carp 

 radialis brevi: 

 Extensor carpi 

 radialis Ion 



Extensor digitorum 

 communis 



Extensor indicis 

 proprius 



~ tensor digiti 

 nti proprius 

 Extensor 

 carpi ulnaris 



Extensor pollicis 

 brevis 



Abductor pollicis 



longus' 



Radial artery 



Flexor pollicis 



Flexor carpi Radial is 



Median nerve 



Palmaris 

 longus 



Flexor 

 digitorum 

 profundus 

 ar artery 

 and nerve 



Flexor~digitorum' Flexor car P i ulnaris 

 sublimis 



FIG. 56. rTransverse section through Forearm immediately proximal to the 

 Wrist -joint to show the arrangement of the Tendons. 



or compartments for the tendons. Each of these is lined by 

 a special mucous sheath, to facilitate the play of the tendons 

 within it. The different compartments may now be success- 



FIG. 57. (From Luschka. ) 



1. Middle metacarpal bone. 



2. Tendon of flexor sublitnis. 



3. Tendon of flexor profundus. 



4. Second lumbrical muscle. 



5. Second dorsal interosseous muscle. 



6. Extensor tendon. 



I., II., and III. The three phalanges. 



ively opened up so that the arrangement of the tendons with 

 reference to the dorsal carpal ligament may be studied. 



The first compartment is placed on the lateral side of the 

 base of the styloid process of the radius, and corresponds with 

 the broad oblique groove which is present in this part of the 



