Document Detail


Reverse engineering of oxygen transport in the lung: adaptation to changing demands and resources through space-filling networks.
MedLine Citation:
PMID:  20865052     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The space-filling fractal network in the human lung creates a remarkable distribution system for gas exchange. Landmark studies have illuminated how the fractal network guarantees minimum energy dissipation, slows air down with minimum hardware, maximizes the gas- exchange surface area, and creates respiratory flexibility between rest and exercise. In this paper, we investigate how the fractal architecture affects oxygen transport and exchange under varying physiological conditions, with respect to performance metrics not previously studied.We present a renormalization treatment of the diffusion-reaction equation which describes how oxygen concentrations drop in the airways as oxygen crosses the alveolar membrane system. The treatment predicts oxygen currents across the lung at different levels of exercise which agree with measured values within a few percent. The results exhibit wide-ranging adaptation to changing process parameters, including maximum oxygen uptake rate at minimum alveolar membrane permeability, the ability to rapidly switch from a low oxygen uptake rate at rest to high rates at exercise, and the ability to maintain a constant oxygen uptake rate in the event of a change in permeability or surface area. We show that alternative, less than space-filling architectures perform sub-optimally and that optimal performance of the space-filling architecture results from a competition between underexploration and overexploration of the surface by oxygen molecules.
Authors:
Chen Hou; Stefan Gheorghiu; Virginia H Huxley; Peter Pfeifer
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2010-08-26
Journal Detail:
Title:  PLoS computational biology     Volume:  6     ISSN:  1553-7358     ISO Abbreviation:  PLoS Comput. Biol.     Publication Date:  2010  
Date Detail:
Created Date:  2010-09-24     Completed Date:  2010-12-03     Revised Date:  2014-09-14    
Medline Journal Info:
Nlm Unique ID:  101238922     Medline TA:  PLoS Comput Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  -     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological
Cell Membrane Permeability
Diffusion
Exercise
Fractals
Humans
Lung / physiology*
Models, Biological*
Oxygen / metabolism*
Pulmonary Alveoli / physiology
Pulmonary Gas Exchange*
Grant Support
ID/Acronym/Agency:
R21 HL093068/HL/NHLBI NIH HHS; R21 HL093068-02/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
S88TT14065/Oxygen
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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