266 ANATOMICAL TECHNOLOGY. 



Tiyioothenaris (Fig. 105) and the base of tlie pollex. The girdlmg 

 must be done with care, so as not to divide any of the tendons at 

 the wrist. Reflect the skin and fascia first upon the caudal (ulnar) 

 side of the antebrachium. 



General Description. — A slender muscle from the cephalic side 

 of the humerus to the distal end of the radius. 



Dissection. — If the antebrachium is extended slightly, the free 

 ventral border of the muscle will appear. The dorsal border is 

 attached by connective tissue to the subjacent muscles, excepting 

 close to the ventral border of the brachiuni, where a large nerve 

 passes between it and the next muscle. Trace this border distad to 

 near the end of tlie radius, noting that the connections with the sub- 

 jacent muscles become firmer toward the wrist. Divide the muscle, 

 and reflect the proximal end ; this sometimes adheres so closely to 

 the cephalic surface of the hrachlalis that, for 5-7 mm. from the 

 humerus, it cannot be separated without cutting fibers. 



Origin. — By a very thin tendon, from the middle fifth of the dor- 

 sal border of the humerus ; a third of the origin line lies between 

 the origin areas of the hrachialis and the cephalic division of tlie 

 entotriceps ; the rest of the line is a direct proximal continuation 

 of the apex of the origin area of the last named muscle, and ceases 

 at the distal end of the origin area of the caudal division. 



Insertion. — By fleshy fibers upon the distal end of the radius, 

 just proximad of the grooves for the tendons of the MM. extensores 

 radiates and upon the adjacent ligaments. 



M. BICEPS. 



§ 691 Synonymy, — The human Mceps hrncliialis, G., A, 408, or biceps flexor ciibiti, Q., 

 A, I, 205 ; " biceps," S.-D., A, II, 353 ; " long flecMsseur de I'avant bras ou biceps brachial" 

 Ch., A, 271 ; long flexor of the forearm or brachial biceps, Ch. (Fl.), A, 255 ; biceps, Miv., B, 148. 



Figures. — Ventro-caudal aspect (72, 73) : cephalic aspect of distal end (74) ; reflected 

 (75) ; origin point, tuberculum bicipitale (45, A, 43) ; insertion point, tuberositas bicipi- 

 talis (30). 



Posture. — At first the arm should rest upon the cephalic side. 

 The muscle was exposed by the division of the Mcipital arch (§ 662). 



General Description. — A long, fusiform muscle extending the 

 whole length of the ventral surface of the brachium, from the 

 bicipital tubercle of the scapula to the bicipital tuberosity of the 

 radius. 



Dissection. — No preliminary dissection is needed beyond freeing 

 the muscle from fascia and connective tissue. After transection, if 



