MUSCLES OF THE FOREARM AND MANUS 



353 



The extensor tendons are bound down at the carpus by an annular hgament, 

 and are furnished with synovial sheaths (Figs. 307, 308). 



B. Flexor Division 

 The three flexors of the carpus are like those of the horse, but the long tendon 

 of the lateral flexor ends on the large metacarpal bone, not on the small one. The 

 tendon of the medial flexor naturally ends on the medial part of the large meta- 

 carpal bone. 



The superficial digital flexor is somewhat blended at its origin with the middle 

 flexor of the carpus. ^ It divides into two bellies, superficial and deep, terminating 



Fig. 307. — Right Carpus of Ox with BtTRS.E and Fig. 308. — Right Carpus of Ox with Buhs.e and 



Synovial Sheaths Injected; Lateral View. Synovial Sheaths Injected; Medial \'iew. 



1, Extensor carpi radialis, with synovial sheatii it') and bursa {I"); 2, extensor carpi obliquus, with synovial 

 sheath {2') and bursa {2"); 3, extensor digiti tertii proprius; 4-, extensor digitalis communis; S' , common synovial 

 sheath of 3 and 4; 5, extensor digiti quarti proprius, with synovial sheath (5') ; 6, 6\ ulnaris lateralis, with bursa 

 i6"); 7, flexor carpi radialis, with synovial sheath; S, deep digital flexor, with synovial sheath (5'): 9, flexor carpi 

 ulnaris; 10, superficial digital flexor, with synovial sheath, W; a, radius; h, carpus; c, metacarpus; d, cut edge of 

 annular ligament. (After Schmidtchen.) 



on tendons at the distal part of the forearm. The superficial tendon passes over 

 the posterior annular ligament (Lig. carpi transversum) , perforates the metacarpal 

 fascia, and joins the deep tendon about the middle of the metacarpus. The deep 

 belly is connected with the deep flexor by a strong fibrous band. Its tendon passes 

 under the annular ligament of the carpus in a groove on the deep flexor, from which 

 it receives fibers. The conjoined tendon soon bifurcates, each branch receiving a 

 reinforcing band from the suspensory ligament, and forming near the fetlock a 

 ring for the corresponding branch of the deep flexor tendon. Passing under two 

 digital annular ligaments, they are inserted into the volar surfaces of the second 

 phalanges by three slips. 

 23 



