Nasal cavities -- two chambers for filtering, warming and humidifying inspired air.

Examine the nasal cavities in the fetal head (slide 130).

• Note its division by the nasal septum and the projecting turbinates (conchae) which protrude into the cavities and serve to increase both the surface area and the air turbulence.
• In the nasal mucosa covering the cartilage of these structures
• Identify the
  • Blood-filled venules, the serous glands, and
  • The pseudostratified, ciliated columnar epithelium.

At the dorsal surface of the nasal cavities, the lining epithelium is modified as olfactory epithelium with cells for olfactory reception (Fig. 17-3), although it does not yet appear to be fully differentiated in this fetal tissue.

What functions are served by the numerous glands and by the thin-walled venules in the nasal mucosa?

Next is the larynx.