58 



TOPOGRAPHICAL ANATOMY OF 



arrives at the distal part of the metacarpus it is only slightly flattened. 

 From tliis point onwards the flattening becomes more and more pro- 

 nounced. In the distal fourth of the metacarpus the tendon of the 

 superficial flexor has an annular appendage through which the tendon 

 of the deep flexor passes. At about the middle of the first phalanx 

 the superficial tendon splits into two limbs that are inserted to the 

 proximal part of the volar aspect of the second phalanx and to the 

 immediately adjacent parts of the first phalanx. 



M. FLEXOR DIGITORUM PROFUNDUS. — The tendon of the deep flexor 

 accompanies the superficial tendon down the back of the carpus — where 

 the two structures are enclosed in a common synovial or mucous sheath 

 — metacarpus and digit. In the distal fourth of the metacarpus the 



t/ 



II. iiiterosseus 



-. M. extensor rligiti quinti. 



M. flexor digitoruiii 

 subliniis. 



M. extensor digitoruni 

 eummunis. 



Fig. 38. — Lateral Aspect of the Skeleton of the Digit, with Areas of Muscular Attachment. 



tendon traverses the ring provided by tlie superficial tendon and then 

 plays over the groove-like surface formed by the two sesamoid bones 

 and the cartilage that clothes their volar face. Then, passing between 

 the two limbs into which the superficial tendon finally divides, it 

 crosses the sesamoid bone of the third phalanx and is inserted to 

 the flexor area of the third phalanx. The ultimate insertion cannot 

 be examined as yet, inasmuch as it is buried within the hoof. 



Careful note should be made of the extensive synovial or mucous 

 sheath associated with the deep and superficial tendons beginning in 

 the distal fourth of the metacarpus and continued to the middle of the 

 second phalanx, where it comes into contact with a similar sheath 

 clothing the deep tendon as it plays over the sesamoid bone of the 

 third phalanx. 



