314 



FASCLE AND MUSCLES OF THE HORSE 



the deep flexor emerges (Fig. 278). A second synovial membrane, the digital 

 synovial sheath (Vagina digitalis), begins at the distal fourth of the metacarpus, 



Fig. 283. — Stxovial Sheaths and Bursas of Distal 

 Part of Right Fore Limb of Horse; Medial 



\'IEW. 



The synovial aheatha (colored yellow) and the joint capsules (colored pink) are injected 



Fig. 284. — Synovial Sheaths and Burs.^ of Distal 

 Part of Right Fore Limb of Horse; Lateral 

 View. 



a. Sheath of extensor carpi obliquus; h, sheath 

 of flexor carpi radialis; c, carpal sheath; d, d' , d" , d"', 

 digital sheath; e, bursa under common extensor ten- 

 don; /, capsule of fetlock joint; 1, extensor carpi ra- 

 dialis; 2, tendon of extensor carpi obliquus; 3, flexor 

 carpi r adialis ; ^, flexor carpi ulnaris ; 5, superficial 

 flexor tendon; 6, deep flexor tendon; 7, suspensory hga- 

 ment; 8, small metacarpal bone; 9, large metacarpal 

 bone ; 10, volar annular ligament of fetlock ; 11, 

 proxim,al digital annular ligament; 12, radius; 13, 

 radiocarpal joint; 14, fetlock joint; 15, cartilage of 

 third phalanx; 16, band from first phalanx to cartilage. 

 (Mter Ellenberger, in Leisering's Atlas.) 



a. Sheath of ejctensor carpi radialis; b, sheath 

 of common extensor; c, sheath of lateral extensor; d, 

 sheath of outer tendon of ulnaris lateralis; e, e' , carpal 

 sheath; /, /', /", digital sheath; g, bursa under com- 

 mon extensor tendon; h, bursa under lateral extensor 

 tendon; i, capsule of fetlock joint; 1, extensor carpi 

 radialis; 2, common digital extensor; 3, lateral digital 

 extensor; 4t ulnaris lateralis; I^', I^" , tendons of Ui 5, 

 superficial fiexor tendon; 6, deep flexor tendon; 7, 

 suspensory' ligament; 5, lateral metacarpal bone; 5, 

 large metacarpal bone; 10, volar annular ligament 

 of fetlock; 11, digital annular ligament; 12, fetlock 

 joint; 13, cartilage of third phalanx; 1^, band from 

 first phalanx to cartilage. (After Ellenberger, in 

 Leisering's Atlas.) 



two or three inches (ca. 5-8 cm.) above the fetlock, and extends to the middle of 

 the secojid phalanx. 



Relations. — The belly of the muscle is related superficially to the ulnar head 

 pf the deep fiexor, the flexor carpi ulnaris, and, at its origin, to the ulnar vessels 



