Document Detail


Mechanical role of expiratory muscle recruitment during eupnea in supine anesthetized dogs.
MedLine Citation:
PMID:  1864783     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
To assess the mechanical role of the expiratory musculature during eupnea, we recorded the electromyographic (EMG) activity of the triangularis sterni, the external oblique, and the transversus abdominis in eight supine lightly anesthetized dogs and have measured the volume generated by the phasic activation of the expiratory muscles. Activation of the expiratory muscles was invariably associated with a decrease in lung volume below the relaxed position of the respiratory system, a volume equal to 41.3 +/- 8.4 ml. This volume represented roughly 20% of tidal volume generated during spontaneous breathing. The fractional expiratory contribution to the tidal volume was unrelated to the size of the animal. Traction on the forelimbs (limb extension), however, tended to enhance the phasic expiratory activation of both the triangularis sterni and the transversus abdominis in the majority of animals. Moreover, after limb extension, the fractional contribution of tidal volume attributed to the phasic activation of the expiratory muscles increased in all but one animal. During spontaneous breathing with the forelimbs extended, roughly 25% of tidal volume was found to be due directly to phasic expiratory muscle contraction. The present observations firmly establish that in supine lightly anesthetized dogs breathing at rest the expiratory component of tidal volume represents a substantial contribution.
Authors:
M A Schroeder; H Y Tao; G A Farkas
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  70     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1991 May 
Date Detail:
Created Date:  1991-09-09     Completed Date:  1991-09-09     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2025-31     Citation Subset:  IM    
Affiliation:
Thoracic Diseases Research Unit, Mayo Clinic, Rochester, Minnesota 55905.
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MeSH Terms
Descriptor/Qualifier:
Anesthesia
Animals
Dogs
Electromyography
Extremities
Lung Volume Measurements
Posture
Respiratory Mechanics / physiology*
Respiratory Muscles / physiology*
Tidal Volume
Vagotomy
Vagus Nerve / physiology
Grant Support
ID/Acronym/Agency:
HL-43865/HL/NHLBI NIH HHS

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


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