Sorption-induced Marangoni microflows in the pulmonary surfactant system

Flows induced by the surface tension gradient (Marangoni effects), which ca n be generated in the specific gas-liquid system of the pulmonary surfactan t in the human lungs, are discussed. The pulmonary liquid starts to flow as a result of local surfactant depletion due to its adsorption on small soli d particles, which arrive to the system with the breathing air. Mathematica l model of this phenomenon is presented and solved to demonstrate that a st rong hydrodynamic signal is induced due to the presence of the surface-acti ve monolayer. Considering the specific features of the analyzed physiologic al system of the pulmonary surfactant, it is hypothesized that such microfl ow can stimulate the phagocyte cells (alveolar macrophages) existing in the liquid for movement in the direction of the particle, what will accelerate natural defense mechanisms. Possible ways of verification of the hypothesi s are briefly discussed.