M. BRACHIALIS. 267 



the scapula is strongly flexed upon the brachium, the tendon of ori- 

 gin of the muscle may be seen to play in the bicipital groove. If 

 now the capsule is opened, the tendon will be seen to be still cov- 

 ered by a special sheath, so that it does not lie free within the cap- 

 sule. If it be desirable to expose the whole tendon, the dissector 

 must divide the coracoid attachment of the entopectoralis and the 

 expanded tendon of the xipJii-Tiumeralis. 



The distal end of the M. biceps must then be freed from general 

 connective tissue, and special note taken of a rather firm tendinous 

 band which connects the caudal side of the muscle with the fascia 

 covering the M. pronator teres. The insertion cannot be seen until 

 some of the antebrachial muscles are removed, but, by lifting the 

 border of the muscle which arises from the epicondyle, it is possible 

 to trace the tendon of the biceps toward a point upon the radius 

 distad of the attachment of the clavo-deltoideus and bracMalis. 



Origin. By a strong, rounded tendon, 1.5 cm. long, from the 

 prominent glerioid lip of the glenoid fossa of the scapula. (In man, 

 a second tendon that of the " short" or " coracoid" head arises 

 from the tip of the Prc. coracoideus.} 



Insertion. By a similar, though slightly shorter, tendon upon 

 the bicipital tuber osity of the radius. An additional slight inser- 

 tion is by the tendinous band above mentioned upon the ventral 

 surface of the pronator teres. 



M. BRACHIALIS. 



692. Synonymy. The human brachiaXis antisus, G., A, 409, Q., A, 1, 206 ; "bra- 

 chial," S.-D., A, II, 354 ; " court flechixseur de Vacant brns ou brachial anterieur" Ch., A, 

 272 ; short flexor of the forearm, Ch. (PI.), A, 256 ; bmchialis anticus, Miv., B, 148. 



Figures. Ectal aspect (74) ; ental aspect (75) ; origin area (68, 71) ; insertion area, 

 indistinctly (30). 



Posture. With this and the remaining muscles the appropriate 

 posture will readily suggest itself to the dissector. 



Exposure. By the reflection of the MM. biceps and supinator 

 longus. 



General Description. From an irregular, long, v-shaped line 

 upon the cephalic surface of the shaft of the humerus to the ulna 

 near its proximal end. 



Dissection. Flex the brachium slightly upon the antebrachium 

 so as to relax the muscle. At the border of the antebrachium push 

 it slightly cephalad, and note that here it is attached to the hume- 



