Document Detail


Smaller is better--but not too small: a physical scale for the design of the mammalian pulmonary acinus.
MedLine Citation:
PMID:  12136124     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The transfer of oxygen from air to blood in the lung involves three processes: ventilation through the airways, diffusion of oxygen in the air phase to the alveolar surface, and finally diffusion through tissue into the capillary blood. The latter two steps occur in the acinus, where the alveolar gas-exchange surface is arranged along the last few generations of airway branching. For the acinus to work efficiently, oxygen must reach the last branches of acinar airways, even though some of it is absorbed along the way. This "screening effect" is governed by the relative values of physical factors like diffusivity and permeability as well as size and design of the acinus. Physics predicts that efficient acini should be space-filling surfaces and should not be too large. It is shown that the mammalian acini fulfill these requirements, small mammals being more efficient than large ones both at rest and in exercise.
Authors:
Bernard Sapoval; M Filoche; E R Weibel
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Publication Detail:
Type:  Journal Article     Date:  2002-07-22
Journal Detail:
Title:  Proceedings of the National Academy of Sciences of the United States of America     Volume:  99     ISSN:  0027-8424     ISO Abbreviation:  Proc. Natl. Acad. Sci. U.S.A.     Publication Date:  2002 Aug 
Date Detail:
Created Date:  2002-08-07     Completed Date:  2002-09-23     Revised Date:  2010-09-14    
Medline Journal Info:
Nlm Unique ID:  7505876     Medline TA:  Proc Natl Acad Sci U S A     Country:  United States    
Other Details:
Languages:  eng     Pagination:  10411-6     Citation Subset:  IM    
Affiliation:
Laboratoire de Physique de la Matière Condensée, Centre National de la Recherche Scientifique, Ecole Polytechnique, 91128 Palaiseau, France. bernard.sapoval@polytechnique.fr
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MeSH Terms
Descriptor/Qualifier:
Animals
Guinea Pigs
Humans
Lung / physiology*
Mammals
Pulmonary Gas Exchange / physiology*
Pulmonary Ventilation / physiology
Rabbits
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