title: Comparative physiology of lung complexity: implications for gas exchange.
abstract: Lungs evolved to increase diffusing capacity by compartmentalizing and reducing the size of individual gas exchange units. This increased the potential for gas exchange limitations from ventilation-perfusion heterogeneity. However, comparative studies on reptiles, birds, and mammals show that heterogeneity is independent of lung complexity.
authors.affiliation: Physiology Division, Department of Medicine, and White Mountain Research Station, University of California-San Diego, La Jolla, California 92037-0623, USA.
authors.forename: Frank L
authors.initials: FL
authors.lastname: Powell
authors.forename: Susan R
authors.initials: SR
authors.lastname: Hopkins
mesh_terms: D000818:Animals; D001717:Birds / Q000502:physiology*; D008168:Lung / Q000502:physiology*; D008322:Mammals / Q000502:physiology*; D010828:Physiology, Comparative; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012104:Reptiles / Q000502:physiology*