30S 



l\ruscles of the Arm. 



Opening 



in the septuiu 



iiiterniuscularo 



laterale lor the 



n.-radialis 



llunienis 



M. brachio- 

 radialis 



jr. exten.sor 



carpi radialis 



;ongus 



M. extensor 



carpi radiali- 



brevis 



M. abiluctor 

 polliii>s 

 longus 



M. extensor 

 pollicia brevis 



Prooessus 



styloideiis 



radii 



Process 



to tlie 111. 



abdnctor 



pollicis 



brevis 



I'l t 



^1 



//i 



/. 



fH 



Hi 



N. triceps 



brachii 



(caput 



longuni) 



JI. Iriceps 



brachii 



(caput 



)ncdiale) 



Septum 



iutcrmusculare 



niediaie 



I'picondylus 

 medialis 



M. pronator 

 . teres 



_ M. flexor 

 carpi ulnaris 



U. flexor 

 carpi radialis 



Hi 



M. flexor 



i~- digitoruni 



Ijnifundus 



Os pisiforme 



T.iganientum carpi 

 traiisversuni 



353. Muscles of 

 the right forearm, 



viewed from in front. 



(The mill. bieei)s, brachiaUs, paltnaris 



longus and flexor digitorum sublimis 



have been reraoTod.) 



M. flexor carpi radialis (see 

 also Fig. 352). Form: flat, oblong- 

 spindle-shaped. Position: super- 

 flcial cm the volar surface of the fore- 

 arm. Origin: epicondylus medialis 

 humeri and fascia antibrachii, fused 

 M'ith its neighbors. Insertion: the 

 flbers go, at flrst diverging, between 

 mm. pronator teres and palmaris lon- 

 gus, radialward and downward, then 

 converge and run by a long, powerful 

 tendon between the mm. brachioradialis 

 aud palmaris longus to the hand, where 

 the tendon, covered by the lig. carpi 

 transversum, lies in the groove of the 

 OS multangulum majus ; finally, cover- 

 ed by the tendon of the m. flexor 

 l)ollicis longus, it goes to the basis 

 OSS. metacarpalis II and III (see Fig. 

 355). In the hand, the bursa ni. 

 flexoris carpi radialis (see Fig. 366) 

 lies between the bone and the tendon. 

 Action: it flexes the hand and pro- 

 nates the forearm. I n n e r \- a t i o n : 

 11. medianus. 



M. flexor carpi uluaris (see 



also Figs. 352, 355, 358 and 360). 

 Form: flat, oblniig-triangular ; above 

 it forms, with its anterior surface, a 

 groove, in which lies the ulnar part 

 of the m. flexor digitorum profundus. 

 Position: superficial on the ulnar 

 margin of the forearm. Origin: 

 partly Irum the epicondylus medialis 

 liuineri and from the fascia antibrachii. 

 fused Mith its neighbors (caput hione- 

 raU) , i)artly liy a long, flat, thin 

 tendon from the posterior surface of 

 the olecriinon and from the niargo 

 dorsalis ulnae (caput ulnare). In- 

 sertion: it runs downward, coming 

 in contact radialward with the m. 

 flexor digitorum sublimis and is attach- 

 ed by a long, powerful tendon to tlie 

 OS pisiforme; the bursa ill. flexoris 

 carpi ulnaris (not shown in figure) is 

 lrei|uently to be found there. Action : 

 it flexes and adducts the hand. In- 

 111' rv a t i on : ii. ulnaris. 



% 



