248 



PHYSIOLOGY OF CENTRAL NERVOUS SYSTEM. 



fifth nerve (see Fig. 109). The sensory fibers originate from the 

 nerve cells in the Gasserian ganglion (g. semilunare) . The branch 



Fig. 108. Diagram 



showing the average area of distribution of the sensory fibers of the 

 trigeminal nerve. (Gushing.) 



N. opht. 



N. max. eup. 



N. max. inf. 



Accessory 

 ; motor 



nucleus. 

 1 1 



Desc. 



motor 



root. 



Principal 

 motor 



nucleus. 



Descending 

 I spinal root. 



Fig. 109. Nuclei of origin of the fifth cranial nerve. (From Poirier and Charpy, after 



Van Gehuchten.) 



that enters the brain ends partly in a collection of cells in the pons, 

 the so-called sensory nucleus, and partly in a column of cells extend- 

 ing posteriorly throughout the length of the medulla. These ceils 



