Pulmonary alveolar blood flow.

Explicit results concerning blood flow, alveolar blood volume, regional differences, and transit time distribution are derived from the sheet-flow theory and compared with experimental evidence available in the literature. A general consistency is indicated. The theory exhibits in a simple form the effects on flow of the arterial, alveolar, and venous pressures, the alveolar area, the mean path length between arterioles and venules, and the tension in the alveolar membrane, both elastic and surface tension; thus the theory provides a quantitative understanding of a large number of factors.