7t;o . THE NERVES. 



In its course, it successively gives off: 



1. Before leaving the internal face of the limb, to pass bun oath the 



of extensor muscles of the fore-arm, a very thick fasciculus, competed <>!' 

 several branches descending and ascending. The latter bend round tin: 

 terminal tendon common to the latissimus dorsi and teres interims, to 

 become lost in the body of the great extensor ; the others reacli either the 

 long and middle extensors, or the inferior portion of the principal muscle 

 the large extensor. 



2. Behind the arm, filaments to the short and small extensors of the 

 fore-arm, and several cutaneous ramuscules, disengaged from beneath the 

 short extensor, that descend beneath the skin on the anterior face of that 

 part. 



3. In the antibrachial region, branches to the anterior extensor and 

 external flexor of the metacarpus, and the two extensors of the digit. 



In brief, we see that the radial nerve animates the whole mass of the 

 extensor muscles of the fore-arm and foot, besides a flexor of the latter, and 

 that it endows the integument of the anterior antibrachial region with 

 sensibility. 



13. Ulnar, or Culito-cutaneous Nerve. (Figs. 347, 18 ; 348, 5.) 



Chiefly formed by fibres from the dorsal pairs, this nerve, less consider- 

 able in volume than the preceding, proceeds backward and downward, and 

 places itself behind the humeral artery, which it accompanies to below the 

 origin of the deep humeral. After crossing the latter vessel, it passes 

 between the long and middle extensors of the fore-arm, and gains the inner 

 side of the elbow, running over the epicondyle, below the ulnar band of 

 the oblique flexor of the metacarpus. It follows the posterior border of that 

 muscle to near the supercarpal or pisiform bone, where it terminates by 

 two branches. In the latter part of its course, it lies beneath the anti- 

 brachial aponeurosis, accompanied by a division of the epicondyloid 

 artery. 



One of the two branches, the cutaneous (Fig. 348, 6), crosses the space 

 between the terminal tendons of the external and oblique flexor muscles of 

 the metacarpus, as well as the antibrachial aponeurosis, to spread itself in 

 several ascending horizontal and descending filaments, beneath the skin of the 

 fore-arm, the anterior face of the knee, and the external side of the cannon. 

 'The other branch, with a ramuscule from the median nerve, constitutes the 

 external plantar nerve. 



In its course, the ulnar nerve gives off two fasciculi of collateral branches. 

 The first (Fig. 347, 19) is detached from the principal trunk a little above 

 the epicondyloid artery, and passes backward and downward between the 

 long extensor of the fore-arm and the pectoralis transversus, supplying some 

 filaments to the latter, and traverses it to become subcutaneous, and to be 

 distributed to the skin of the fore-arm, beneath the elbow. The second 

 arises at the epicondyle, and is destined to all the muscles of the posterior 

 antibrachial region, except the external and internal flexors of the 

 metacarpus. 



14. Median, or Ctibito-plantar Nerve. (Fig. 347, 20.) 



This nerve is composed of fibres coming from the dorsal and eighth 

 cervical pairs. It is detached from the posterior part of the trunk of the 

 plexus to proceed to the axillary artery, where it forms an anastomosis with 



