Fig. 1.
Model control volume. The source of soluble gas for this diagram is the blood (pulmonary venous and bronchial arterial). Blood enters the bronchial bed compartment with a partial pressure, Pa. Soluble gas is transported by secretion and diffusion across a series of annular layers before entering the passing airstream. The ratio of gas solubility between the mucus and air layers is specified by a water-air partition coefficient, λw. The thickness of the mucus (Lm), connective tissue (Lt), and adventitial layer (Lad) are calculated from data in the literature.