Mucosa of nasal cavity

At a glance

English

Mucosa of nasal cavity

Latin (TA2)

Tunica mucosa nasi

System

Respiratory

Region

Whole body

Side

Single, on the midline

About the mucosa of nasal cavity

The mucosa of the nasal cavity covers the whole inside of the nose behind the vestibule: the floor, the roof, the nasal septum and the lateral wall with its three curled conchae and the meatuses below them. It is continuous through small openings with the lining of the paranasal sinuses and the nasolacrimal duct, and behind with the mucosa of the nasopharynx. At the nostrils it gives way to the skin of the vestibule, which carries coarse hairs.

Two kinds of mucosa are recognised. The respiratory region, which covers most of the cavity, is lined by ciliated pseudostratified columnar epithelium with many goblet cells and seromucous glands. Beneath it, especially over the inferior and middle conchae, lie large thin-walled venous spaces that can fill and empty and so change the thickness of the lining; the two sides usually swell and shrink in turn over a few hours, the nasal cycle. The olfactory region is a small yellowish area in the roof, on the upper septum and the superior concha, containing the receptor cells for smell, whose fibres pass up through the cribriform plate.

As air flows over the large surface of the conchae it is warmed close to body temperature and saturated with water. Particles and microbes stick to the mucus blanket, and the cilia sweep this backwards to the pharynx to be swallowed. Glands also add antibacterial substances to the mucus.

Its rich blood supply explains why nosebleeds are common, most often from Little's area at the front of the septum where several arteries join. Colds and allergies make the mucosa swell and run, blocking the nose, and decongestant sprays work by shrinking the venous spaces. Infection can spread from here into the sinuses.

Function and supply

Function

Warms, moistens and filters inspired air, traps and clears particles by mucus and cilia, and in its olfactory part detects smell.

Nerve supply

Olfactory nerves for smell; general sensation from the ophthalmic (anterior ethmoidal) and maxillary divisions of the trigeminal nerve; secretomotor fibres via the pterygopalatine ganglion.

Blood supply

Sphenopalatine, greater palatine, anterior and posterior ethmoidal and superior labial arteries, meeting at Little's area on the septum.