1300 



HUMAN ANATOMY. 



and palmaris longus lying mesial and that of the flexor carpi radialis lateral to it 

 (Fig. 1095). It passes into the hand beneath the anterior annular ligament, at the 

 lower margin of which it spreads out into a reddish gangliform swelling, which lies 

 upon the flexor tendons. Below this point it breaks up into its terminal branches. 



Branches. The median, as is the case with the ulnar, gives off no branches 

 in the arm. In the forearm the branches are : (a} the articular, (3) the muscular, 

 (c) the anterior interosseous and (d) the palmar cutaneous, and in the hand : (e) the 

 muscular and (_/) the digital. 



a. The articular branch consists of one or two tiny twigs which supply the anterior portion 

 of the elbow joint. 



FIG. 1096. 



Brachial artery 



Musculo-spiral nerve 



Cephalic vein 



Posterior interosseous nerve 



Brachio-radialis muscle 

 Radial nerve 



Radial recurrent artery 



Communications between 



deep and superficial 



veins 



Cutaneous branch of musculo- 

 cutaneous nerve 



Radial vein 



Radial artery 



Median nerve 



ichial vein 



Tendon of biceps 



. .^Internal cutaneous nerve 



Bicipital fascia 

 Median nerve 



Pronator radii teres 



Superficial dissection of right arm, showing relations of nerves to blood-vessels on front of elbow. 



b. The muscular branches (rr. musculares) (Fig. 1095) consist of a fasces of nerve-bundles 

 which arise from the median a short distance below the elbow. They are distributed to the 

 pronator radii teres, the flexor carpi radialis, the palmaris longus and that portion of the flexor 

 sublimis digitorum which arises from the inner condyle and from the ulna. Two additional 

 filaments from the median supply the flexor sublimis, one entering the radial head and the 

 other that portion which flexes the index finger. 



c. The anterior interosseous nerve (n. interosseus antebrachii volaris) (Fig. 1098) arises 

 from the posterior aspect of the median a short distance below the elbow. It passes down 

 the forearm, accompanied by the anterior interosseous artery, on the anterior surface of the 

 interosseous membrane between the flexor longus pollicis and the flexor profundtis digitorum. 

 At the upper margin of the pronator quadratus muscle it dips under that muscle and continues 

 down for sonic distance, finally entering the deep surface of the pronator quadratus. 



