Modeling Lung Cilia in the Periciliary Layer
Lynn Bennethum (Ph.D. University of Colorado Denver, lead investigator)
Kannanut Chamsri (University of Colorado Denver, graduate student)
Russell Bowler, M.D. Ph.D. (National Jewish Health, consultant)
As we breathe our lungs need to expel pollutants and other invading sources such as viruses and bacteria and their byproducts. They are trapped, transported, and sometimes chemically disarmed in the mucus layer - a thick, very viscous fluid. When we are healthy this layer is quite thin, but if we are fighting an infection, the mucous layer can grow 10 to 100 times thicker.
The expelling of the mucus consists of two mechanisms: the coupling between liquid and airflow (e.g. breathing/coughing) and the force from metachronal waves generated by the coherent beating of cilia - small hair-like structures. The primary transport mechanism responsible for the removal of mucus and cellular debris from the lung is the second mechanism, the so-called muco-ciliary clearance.
This figure shows the cross-section of a major bronchiole. The muco-ciliary system consists of two layers. The lower layer, in which the cilia beat, is known as the periciliary layer (PCL), and the upper layer consists of the mucus. The beat cycle of the cilium is three-dimensional, and on its forward stroke, the cilium extends into the mucus layer.
The objective of this project is to develop a model for the PCL layer and to determine the boundary condition between the PCL and mucus layer.