An alternative view of the role(s) of surfactant and the alveolar model

Currently, the study of surfactant proteins is much in vogue, but, in the early days, the physics underlying surfactant function was treated somewhat superficially, leaving assumptions that have become culturally embedded, such as the "bubble" model of the alveolus. This review selectively reexamines these assumptions, comparing each combination of alveolar model and role of surfactant for compatibility with the major features of pulmonary mechanics and alveolar stability, morphology, and fluid balance.