Olfactory Epithelium

Abstract

The olfactory epithelium localised in the olfactory area of the nasal cavities represents the sensory organ for the highly sensible odorant reception. The epithelium bears the bipolar sensory neurons, which are embedded in surrounding supporting cells. The neuronal dendrites form the characteristic knob-like sensory endings on the luminal side of the epithelium; the basal cell areas give rise to the axonal projections (neuritic processes), which eave the epithelium, become surrounded by extensions of olfactory myelin-producing cells, and form the fila olfactoria, which pierce the cribriform plate of the ethmoid bone and approach special synapse regions at the olfactory bulb. Basal cells, immature neurons and supporting cells are found in the basal and medial regions of the epithelium. The basal cells are mitotically active; their daughter cells differentiate into neurons during adult life. Two different types of microvillibearing epithelial cells exist, which in part are seen in connection with sensory properties and in part are comparable with brush cells (cf. Fig. 79), and are involved in transport processes responsible for an optimal ionic milieu at the epithelial surface.