Nasal cycle

A CT scan showing evidence of the nasal cycle. The more open airway is on the right; the swollen turbinates congest the left

The nasal cycle is the alternating partial nasal congestion and decongestion of the nose cavities. It occurs in humans and other mammals. The individual is usually not aware that it happens.^[1]^[2]

It results in greater airflow through one nostril, and regular alternation between the nostrils. The hypothalamus selectively activates each half of the autonomic nervous system in turn. The phenomenon is quite normal.

What happens

The cilia of the congested side suspend their motility until that side decongests. The cycle means that, at any time, one side of the nose is moist, and moistens the incoming air. This is one of the three functions of the nose. The other two are the filtration and warming of fresh air before it gets to the lungs.^[3]

It is not entirely clear what the benefit is of this system.

References

↑ Huizing, E. H.; de Groot, J.A.M. (2003). Functional reconstructive nasal surgery. Thieme. pp. 52. ISBN 978-1-58890-081-4.
↑ Josephson J.S. 2006. Sinus relief now: the ground-breaking 5-step program for sinus, allergy, and asthma sufferers. London, Penguin. pp. 15. ISBN 978-0-39953-298-6
↑ Thomas Hummel & Antje Welge-Lüssen 2006. Taste and smell: an update. Karger Medical and Scientific Publishers. ISBN 978-3-8055-8123-3

[huizing52-1] Huizing, E. H.; de Groot, J.A.M. (2003). Functional reconstructive nasal surgery. Thieme. pp. 52. ISBN 978-1-58890-081-4.

[josephson-2] Josephson J.S. 2006. Sinus relief now: the ground-breaking 5-step program for sinus, allergy, and asthma sufferers. London, Penguin. pp. 15. ISBN 978-0-39953-298-6

[3] Thomas Hummel & Antje Welge-Lüssen 2006. Taste and smell: an update. Karger Medical and Scientific Publishers. ISBN 978-3-8055-8123-3

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