REGIONS OF THE NASAL MUCOSA
The nasal mucosa can be divided into three clear regions:
Vestibular region
This is a stratified squamous epithelium characterised by an epidermis that has lost its corneal covering and has no glands.
Olfactory region
This region has a thin, brownish-yellow mucosa called the locus luteus. It is poor in mucus glands and is characterised by the presence of olfactory receptor elements. It is located in the olfactory area and makes up the whole top part of the nasal fossa located above the olfactory groove.
Histologically it is comprised of a stratified cylinder-like epithelium and the chorion. The epithelium contains the olfactory or olfactory receptor cells, also known as Schultze’s cells, the stable cells and the basal cells. The chorion is characterised by the presence of voluminous tubuloacinar glands called Bowman’s capsules.
Respiratory region
The respiratory mucosa, or Schneider’s membrane, takes up the greatest part of the nasal surface. Microscopically, it is comprised of a stratified cylindrical and ciliated epithelium and has three cell types: mucus-secreting, goblet and basal. The chorion has a considerable number of vascular elements, particularly venous, and glands in a single layer with mucous and serous cells.