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 fiber* of the 

 trigeminal nerve. (Gushing.) 



max. rup. 



N. max. inf. 



j Principal 

 I motor 

 ! nucleus. 



Descending 

 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 cells 



