Textbook of normal histology: including an account of the development of the tissues and of the organs . eculiar modifications of theracemose type. The olfactory region is distinguished macroscopically from therespiratory portions of the nasal fossae by the yellowish-browntinge of its mucous membrane as contrasted with the rosy hue ofthat covering the adjacent region ; the more deeply colored tractindicates in only a general way the boundaries of the olfactoryregion, since the limits of the two do not closely correspond, thebrownish area in man being usually somewhat less extensive thanthe ent
Textbook of normal histology: including an account of the development of the tissues and of the organs . eculiar modifications of theracemose type. The olfactory region is distinguished macroscopically from therespiratory portions of the nasal fossae by the yellowish-browntinge of its mucous membrane as contrasted with the rosy hue ofthat covering the adjacent region ; the more deeply colored tractindicates in only a general way the boundaries of the olfactoryregion, since the limits of the two do not closely correspond, thebrownish area in man being usually somewhat less extensive thanthe entire surfacepossessing thestructure of the ol-factory mucousmembrane. Thelatter is also dis-tinguished by itsgreater thicknessand by the absenceof ciliated cells. The olfactorymucosa consists ofthe epithelium andthe tunica propria,the characteristicappearances of thetissue dependingupon the peculiari-ties of the former, another example of neuro-epithelium. This epi-thelium consists of two kinds of cells, the sustentacular and theolfactory elements. The sustentacular or support cells present Fig. Section through olfactory mucous membrane from childs nose : a,zone of oval nuclei belonging to sustentacular cells; b, zone ofspherical nuclei of olfactory elements ; c, basilar cells; d, subepi-thelial tissue ; e, glands of Bowman. 404 NORMAL HISTOLOGY. an outer cylindrical division, containing an oval nucleus, situatedalways near the inner end of the more expanded part of the cell, andyellowish pigment, together with numerous granules arrangedmore or less markedly in longitudinal rows. The outer ends of thesupporting cells are modified into a cuticular zone, the membranalimitans olfactoria, sometimes exhibiting vertical markings. The nuclei of the sustentacular cells form a regular band, thezone of oval nuclei, which lies next the free surface, and strongly con-trasts with the adjoining broad zone of round nuclei of the olfac-tory cells. The inner portions of the sustentacular e
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Keywords: ., bookauthorpiersolgeorgeageorgea, bookcentury1800, bookdecade1890
