Document Detail

The influence of locomotion on air-sac pressures in little penguins.
MedLine Citation:
PMID:  11707507     Owner:  NLM     Status:  MEDLINE    
Air-sac pressures have been reported to oscillate with wing beat in flying magpies and with foot paddling in diving ducks. We sought to determine the impact on air-sac pressure of wing beats during swimming and of the step cycle during walking in little penguins (Eudyptula minor). Fluctuations averaged 0.16+/-0.06 kPa in the interclavicular air sacs, but only 0.06+/-0.04 kPa in the posterior thoracic sac, generating a small differential pressure between sacs of 0.06+/-0.02 kPa (means +/- S.E.M., N=4). These fluctuations occurred at approximately 3 Hz and corresponded to wing beats during swimming, indicated by electromyograms from the pectoralis and supracoracoideus muscles. There was no abdominal muscle activity associated with swimming or exhalation, but the abdominal muscles were active with the step cycle in walking penguins, and oscillations in posterior air-sac pressure (0.08+/-0.038 kPa) occurred with steps. We conclude that high-frequency oscillations in differential air-sac pressure enhance access to and utilization of the O(2) stores in the air sacs during a dive.
D F Boggs; R V Baudinette; P B Frappell; P J Butler
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of experimental biology     Volume:  204     ISSN:  0022-0949     ISO Abbreviation:  J. Exp. Biol.     Publication Date:  2001 Oct 
Date Detail:
Created Date:  2001-11-14     Completed Date:  2002-01-22     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0243705     Medline TA:  J Exp Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  3581-6     Citation Subset:  IM    
Department of Biology, Hall of Sciences 258, Eastern Washington University, Cheney, WA 99004, USA.
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MeSH Terms
Abdominal Muscles / physiology
Air Sacs / physiology*
Birds / physiology*
Motor Activity / physiology*
Muscle, Skeletal / physiology
Oxygen Consumption
Swimming / physiology
Transducers, Pressure
Walking / physiology

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

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