Muscles of the Upper Extremity. 



183 



Tendo 

 M.ext.carp.uln. 



TM.ext.carp.rad. long. 

 TM.exuarp.rad.brev. 



Tendo 



M. e/t.ossis melac. 

 poll. 



Tendo 



M.extsee. intern. 



poll. 



Tendo 



M.ext.primi 



intern.poll. 



Lateral 

 Slips 



243. The Extensor Tendons 



Hand. 



at the Back of the 



M. supinator longus (Fig. 238) arises from the lower third of the 

 external border of the humerus, and is inserted into the lower extremity 

 of the radius above the styloid process. (Chiefly flexor of the forearm.) 



M. supinator brevis (Fig. 244) arises from the external condyle of 

 the humerus and the orbicular ligament of the radius, and is inserted into 

 the inner surface of the radius below the tuberosity. (Strong supinator.) 



M. extensor carpi radialis longior s. radialis externus longus (Fig. 240, 244) 

 arises above the external condyle of the humerus, and is inserted into 

 the base of the metacarpal bone of the index finger. (Extensor and 

 adductor of the hand.) 



M. extensor carpi radialis brevior s. radialis externus brevis (Fig. 240, 244) 

 arises from the external condyle of the humerus and the orbicular liga- 

 ment of the radius, and is inserted into the base of the metacarpal bone 

 of the middle finger. (Extensor and adductor of the hand.) 



