Document Detail

Immediate diaphragmatic electromyogram responses to imperceptible mechanical loads in conscious humans.
MedLine Citation:
PMID:  1506377     Owner:  NLM     Status:  MEDLINE    
We used an esophageal electrode to measure the amplitude and neural inspiratory and expiratory (N TE) timing responses of crural diaphragmatic electrical activity in response to flow-resistive (R) and elastic (E) loads at or below the threshold for conscious detection, applied pseudorandomly to the oral airway of eight normal subjects. We observed a rapid first-breath neural reflex that modified respiratory timing such that N TE lengthened significantly in response to R loads in six of eight subjects and shortened in response to E loading in six of seven subjects. The prolongation of N TE with R loading resulted primarily from lengthening the portion of N TE during which phasic activity in the diaphragm is absent (TE NDIA), whereas E loading shortened N TE mainly by reducing TE NDIA. Most subjects responded to both types of loading by decreasing mean tonic diaphragmatic activity, the average level of muscle activity that exists when no phasic changes are occurring, as well as its variability. The observed timing responses are consistent in direction with optimally adaptive pattern regulation, whereas the modulation of tonic activity may be useful in neural regulation of end-expiratory lung volume.
E J Kobylarz; J A Daubenspeck
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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:  73     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1992 Jul 
Date Detail:
Created Date:  1992-09-21     Completed Date:  1992-09-21     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:  248-59     Citation Subset:  IM; S    
Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire.
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MeSH Terms
Diaphragm / innervation,  physiology*
Middle Aged
Muscle Tonus / physiology
Neurons / physiology
Physical Stimulation
Respiratory Mechanics / physiology
Respiratory Muscles / physiology
Grant Support

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

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