Modeling structure-function interdependence of pulmonary gas exchange.

Modeling functional processes, such as gas exchange, that occur deep in the lung far from where one can directly observe, depends on knowledge about the precise and quantitative design of the structure of the gas exchanger. This is the case as well for the actual arrangement of alveoli and blood capillaries at the gas exchange surface as for the disposition of gas exchange units with respect to the airway and vascular trees. The serial arrangement of alveoli and their perfusion as parallel units have important consequences for gas exchange.