THE NASAL CAVITY 



297 



The neuro-epithelium contains three intermingled cell types, the 

 sustentacular, olfactory, and basal cells. 



The SUSTENTACULAR CELLS are columnar ciliated epithelial cells 

 which possess a distinct cuticular margin. Their nuclei are ovoid, and, 

 since they lie at the same level, they form a continuous superficial zone 

 of oral nuclei. The deep ends of the cells are often branched; they 

 interlace with one another and with the processes of the olfactory and 



-sr 



FIG. 283. THE OLFACTORY Mucous MEMBRANE. 



a, duct of gland; b, basal cells; c, cuticular border with olfactory cilia; k, nuclei 

 of the sustentacuLir cells; k', nuclei of the olfactory cells; r, layer of olfactory cells; 

 s, corium, containing connective tissue cells and nerve fibers; st, sustentacular 

 cells. X 465. (After Kolliker.) 



basal cells. The cytoplasm of the sustentacular cells is finely granular 

 and contains a yellow pigment. 



The OLFACTORY CELLS occupy a unique position among neuro-epithe- 

 lial cells in that they are true nerve or ganglion cells. They possess a 

 small cytoplasmic body and two processes, a distal and a central. Their 

 nuclei are spherical and are disposed in several rows beneath the nuclear 

 zone of the sustentacular cells ; thus they form a broad zone of spherical 

 nuclei. The distal process of the olfactory cell projects as a slender 

 filament whose free end, carrying several fine cilia, reaches the surface of 



