THE SPINAL NERVES. 



715 



recurrente). The sensibility of the anterior root, therefore, ceases at once as soon 

 as the posterior root is divided. In conjunction with the loss of sensibility of 

 the anterior roots thus brought about, that of the surface of the spinal cord in 

 the vicinity of the root is also abolished. A considerable time after division of the 

 anterior root (if degeneration has already taken place), a number of fibers that 

 are not degenerated are found in its peripheral extremity, while a number of 

 degenerated (sensory) fibers are present in its central stump. In cases in which 



A B 



\lk A 



*j 



FIG. 248. Distribution of the Cutan?ous 

 A. Anterior aspect: i, crural nerve; 2, external 

 or lateral cutaneous nerve of the femur, 

 Henle; 3, ilioinguinal nerve; 4, lumboin- 

 guinal nerve; 5, external spermatic nerve; 

 6, posterior cutaneous nerve; 7, obturator 

 nerve; 8 greater saphenous crural nerve; 9, 

 communicating peroneal or fibular nerve; 10, 

 superficial peroneal nerve; u, deep peroneal 

 nerve; 12, communicating tibial or sural 

 nerve. 



Nerve of the Lower Extremity (after Henle). 



B. Posterior aspect: i, posterior cutaneous nerve; 

 2, external or lateral cutaneous nerve of the 

 femur, Henle; 3, obturator nerve; 4, poste- 

 rior median cutaneous nerve of the femur 

 (peroneal nerve); 5, communicating peroneal 

 or fibular nerve; 6, greater saphenous nerve 

 (crural nerve); 7, communicating tibial or 

 sural nerve;- 8, proper plantar cutaneous nerve 

 (tibial nerve); 9, middle plantar nerve (tibial 

 nerve); 10, lateral plantar nerve (tibial nerve). 



the motor fibers were degenerated, Schiff found unaltered fibers in the anterior 

 root, and these passed over to the spinal meninges. In rare cases the anterior root 

 receives its sensibility, besides, from other sources than from its corresponding 

 posterior root. The passage of sensory fibers into the motor root takes place 

 either at the point of junction between the two roots, or in the plexus, or in the 

 vicinity of the peripheral terminal distribution. Thus, sensory fibers passing in a 

 centripetal direction also enter from the periphery into several motor branches 



