REGIONAL ANATOMY 



21 



Action. — This muscle flexes the second phalanx on the 

 first, the first on the metacarpus, and the entire foot on the 

 forearm. Mechanically, it acts as a stay when the animal 

 is standing by maintaining the metacarpophalangeal angle. 



The Flexor Pedis Perforans, or the Deep Flexor of 

 the Phalanges. — This muscle consists of three easily- 

 divided portions : an ulnar, a humeral, and a radial, and has 



Fig. 13. — Median Section of Foot. 



A, Os suffraginis ; B, os coronae; C, os pedis; D, navicular bone; 

 E, tendon of the extensor pedis ; F. insertion of the extensor 

 pedis into the pyramidal process of the os pedis ; G, the tendon 

 of the flexor perforatus ; H, insertion of perf oratus into the os 

 corona?; /. tendon of the flexor perf orans ; J, its passing attach- 

 ment to the os corona? ; K, its final insertion in the semilunar 

 crest of os pedis ; a, section of coronary cushion ; b, section of 

 plantar cushion ; c, semilunar sinus of os pedis. 



for points of origin the olecranon process of the ulna, the 

 inner condyloid ridge of the humerus, and the posterior sur- 

 face of the radius. These portions are continued by a com- 

 mon tendon which enters the carpal sheath with the tendon 

 of the perforatus, and continues with it through the synovial 



