PHYSIOLOGY OF THE NOSE
The nasal lining produces watery and mucoid secretions, transports them backwards and clears them into the nasopharynx. The lining of the paranasal sinuses also produces secretions, and the cilia within the sinuses beat in such a way as to drive the secretions always towards the natural openings of the sinuses into the nose. There is thus a continuing ‘mucociliary transport system’ within the healthy nose and sinuses which produces and clears secretions constantly. It is impossible to assign a function to the paranasal sinuses. It has been suggested that they lighten the bones of the skull and assist in the natural carriage of the head, but a distinguished anatomist has pointed out that the weight of a pipe and a pair of spectacles more than compensates for the amount of spongy bone dispensed with. It is possible that the sinuses contribute to the natural resonance of the voice, and this is much discussed by teachers of singing, but I am aware of no evidence that those individuals lacking a frontal sinus, for example, have a substantially different nasal resonance to those with a large one.