THE ORAL CAVITY. 



237 



mouth (lip) the glands extend also into the submucosa. The 

 mucosa and epithelium lining the mouth cavity are richly 

 supplied with nerves which terminate either in special sensory 

 nerve-endings or in free sensory nerve-endings, or on the blood- 

 vessels. In the papillae of the mucosa are found corpuscles of 

 Krause. (See p. 169.) , The nerves terminating in free sensory 

 endings are the dendrites of sensory neurones (medullated sensory 

 nerves), which, while yet medullated, branch and form plexuses 

 with large meshes, situated in the submucosa and deeper portion of 



Transitional zone with 

 irregular papillae. 



Mucous 



Fig. 180. Section through the lower lip of man ; X I & 



the mucosa. The medullated branches of the nerve-fibers constitut- 

 ing these plexuses proceed toward the epithelium, dividing further 

 in their course. Immediately under the epithelium the medullated 

 branches lose their medullary sheaths, divide further, and form the 

 subepithelial plexuses. The nonmedullated branches enter the 

 epithelium, where they form telodendria (end-brushes), the terminal 

 branches of which surround the epithelial cells, between which 

 they end either in very fine granules or in small groups of such, or, 

 again, in variously shaped end-discs. (See Fig. 135.) The blood- 



