26 THE NECTURUS 



Extensor ulnaris 



At the posterior border of the extensor metacarpalia a 

 portion of the extensor ulnaris can be seen. With the 

 covering muscle removed, it is very evident on the pos- 

 terior border of the limb. It originates on the outer face 

 of the distal end of the humerus and on the olecranon 

 process of the ulna and is inserted at the base of the 

 metacarpal number four. 



Supinator 

 When the extensor metacarpalia is removed, the fibers 

 of the supinator are seen on the carpus. This muscle 

 originates on the middle of the carpus and is inserted at 

 the base of the first toe. 



MUSCLES OF THE PALMAR SURFACE 



As seen superficially, the flexors of the palm are three 

 in number. The median is the palmaris superficialis, the 

 anterior the flexor radialis and the posterior the flexor 

 ulnaris. The last must be dissected loose with care as it 

 is closely associated with the palmaris. 



Palmaris superficialis 



This is the large median muscle of the palm. Dissect it 

 loose at the borders. It ends in the palmar fascia. The 

 origin is on the condyle of the humerus. 



Lift the palmaris superficialis, cut through at the middle 

 and deflect. Four muscles can be seen with this dissection 

 completed. 



Flexor ulnaris 



The origin of this posterior muscle is on the humerus. 

 Extending distally it is inserted on the carpals at the base 

 of the fourth toe. 



