GAS-TRANSPORT IN AN ASYMMETRICAL ACINUS

Abstract

The pattern of gas transport is examined within a branching nodal representation of an isotropically expanding, asymmetric acinus, distal to the respiratory bronchioles. The model acinus is matched onto a proximal, rigid, trumpet-shaped conducting zone, and single breaths of O2 He and SF6 are simulated by numerical solution of the equation for gas transport within the resulting composite model. The time variation of gas concentrations and their serial and parallel differences during the respiratory cycle are shown, and the mechanisms responsible are highlighted. The results confirm the unequal distribution of inspired gas between parallel pathways, predicted from studies of isolated asymmetr..