Effect of Fluid Viscosity on the Cilia-Generated Flow on a Mouse Tracheal Lumen


Mucous flow in a tracheal lumen is generated by the beat motion of ciliated cells to provide a clearance function by discharging harmful dust particles and viruses. Due to its physiological importance, the cilia-generated flow and the rheological properties of mucus have been investigated intensively. The effects of viscosity on the cilia-generated flow, however, have not been fully clarified. In this study, we measured bulk background velocity of ciliary flow using a micro particle tracking velocimetry method under various viscosity conditions in mice. The results showed that the flow velocity decreased as the increase with viscosity of ambient fluid. Moreover, no previous study has clarified the pump power generated by cilia, which provides important information with regard to understanding the molecular motor properties of cilia. Measurements of both the ciliary flow and the ciliary motion were conducted to determine the cilia pump power. Our results indicated that the cilia pump during the effective stroke did not drive the ciliary flow efficiently under high viscosity conditions; these findings are necessary to resolve the clearance function.

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This research was supported by JSPS KAKENHI [Grant Numbers 25000008 and 26242039].

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The authors certify that no conflict of interest is raised by this work.

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Correspondence to Kenji Kikuchi.

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Associate Editor Merryn Tawhai oversaw the review of this article.

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Kikuchi, K., Haga, T., Numayama-Tsuruta, K. et al. Effect of Fluid Viscosity on the Cilia-Generated Flow on a Mouse Tracheal Lumen. Ann Biomed Eng 45, 1048–1057 (2017) doi:10.1007/s10439-016-1743-y

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  • Cilia
  • Fluid mechanics
  • Transport phenomena
  • Cilia pump power
  • Particle tracking velocimetry