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BP: Fachverband Biologische Physik
BP 29: Statistical Physics of Biological Systems I (joint session BP/DY)
BP 29.4: Talk
Thursday, March 15, 2018, 10:15–10:30, H 2013
The labyrinth-like shapes of nasal cavities arise from physical and geometrical constraints — •David Zwicker1,2, Rodolfo Ostilla-Mónico2, Daniel E. Lieberman2, and Michael P. Brenner2 — 1Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany — 2Harvard University, Cambridge, USA
Although the nasal cavity is vital for heating and humidifying inhaled air in all vertebrates, its shape varies widely across animals. To understand this variability, we here connect nasal geometry to its function by theoretically studying the airflow and the associated scalar exchange that describes heating and humidification. We show that optimal geometries, which have minimal resistance for a given exchange efficiency, are narrow with a uniform gap width. Our prediction for the gap width matches measured values over a large range of animal sizes. Moreover, we show that geometric constraints imposed by the head can be satisfied with the observed labyrinth-like geometries, which perform almost as well as the optimal shapes without the constraints. Taken together, our theory explains the geometric variations of natural nasal cavities quantitatively and we hypothesize that the trade-off between high exchange efficiency and low resistance to airflow is the main driving force shaping the nasal cavity.