MUSCLES OF THE FOREARM. 



FIG. 46. 



Extensor Minimi Di,iti,' from the common tendor and the intermusculai 



septa, into the 2d and 3d phalanges of the little finger, with the tendon 



derived from the common extensor. Action, as 



named. Nerve, posterior interosseous. 

 Extensor Carpi Ulnaris,/ from the common tendon, 



the middle one-third of the posterior border of the 



ulna, and the fascia of the forearm, into the base 



of the 5th metacarpal bone. Action, to extend the 



wrist. Nerve, posterior interosseous. 



Anconeus,yr0w the external condyle of the humerus, 

 posteriorly, into the side of the olecranon, and 

 upper one-third of the posterior surface of the shaft 

 of the ulna. Action, to extend the forearm. Nerve, 

 the musculo-spiral. 



Supinator Brevis, from the external condyle of the 

 humerus, the external lateral and orbicular liga- 

 ments, and an oblique line on the ulna, into the 

 inner surface of the neck of the radius, the outer 

 edge of its bicipital tuberosity, and the oblique line. 

 Action, to supinate the hand. Nerve, posterior in- 

 terosseous, which pierces it. 



Extensor Ossis Metacarpi Pollicis, 14 from the pos- 

 terior surfaces of the shafts of the radius and ulna, 

 and the interosseous ligament, into the base of the 

 metacarpal bone of the thumb. Action, to extend 

 the thumb. Nerve, posterior interosseous. 



Extensor Primi Internodii Pollicis, from the pos- 

 terior surface of the shaft of the radius and the in- 

 terosseous membrane, into the base of the 1st 

 phalanx of the thumb. Action, to extend the thumb, 

 interosseous. 



Nerve , posterior 



Extensor Secundi Internodii Pollicis,^ from the shaft of the ulna poste- 

 riorly and the interosseous membrane, into the base of the last phalanx 

 of the thumb. Action, to extend the thumb. Nerve, posterior inter- 

 osseous. 



Extensor Indicis, from the shaft of the ulna posteriorly and the interosseous 

 membrane, into the 2cl and 3d phalanges of the index finger with the 

 tendon of the common extensor. Action, to extend the index finger. Nervt, 

 posterior interosseous. 

 8* 



