| Ventilatory adjustments during sustained mechanical loading in conscious humans. | |
| | |
MedLine Citation:
|
PMID: 6629954 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Ventilatory responses to inspiratory elastic and resistive loads of 67 men were analyzed. During the 1st, 5th, and 10th consecutively loaded breaths 1) individual responses ranged from a rapid-shallow to a slow-deep breathing pattern; 2) strong tidal volume (VT) defenders employed longer inspirations than did weak VT defenders; and 3) individual frequency responses were mediated by changes in inspiratory and/or expiratory timing. Thus the group response was qualitatively similar on the 1st, 5th, and 10th loaded breaths. Quantitatively, however, the group's mean minute ventilation increased throughout each episode owing to progressively larger tidal volumes coupled with equal breathing frequencies. During elastic loading this amplified VT defense was achieved by stronger inspirations with no systematic changes in timing, whereas during resistive loading it was achieved both by stronger and longer inspirations. Inspiring 5% CO2 induced a degree of hypercapnia exceeding that accompanying mechanical loading and yet elicited a comparatively modest enhancement of respiratory output. These findings suggest that in conscious humans 1) repeated mechanical loading activates neural load-compensating mechanisms; 2) the range of these neural adjustments varies with both load size and type; and 3) the stimulus to initiate this behavior is largely nonchemical. |
| | |
Authors:
|
K Axen; S S Haas; F Haas; D Gaudino; A Haas |
Related Documents
:
|
10362054 - Influence of immersion on respiratory requirements during 30-min cycling exercise. 17428714 - Inhaled furosemide does not alleviate respiratory effort during flow-limited exercise i... 11549134 - Work performance when breathing through different respirator exhalation resistances. 8424574 - Effects of thoracic extradural block on diaphragmatic electrical activity and contracti... 12126994 - The effects of exercise intensity on thermoregulatory responses to exercise in women. 10846004 - Simultaneous nmr microdialysis study of brain glucose metabolism in relation to fasting... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
|
Title: Journal of applied physiology: respiratory, environmental and exercise physiology Volume: 55 ISSN: 0161-7567 ISO Abbreviation: J Appl Physiol Publication Date: 1983 Oct |
Date Detail:
|
Created Date: 1983-12-20 Completed Date: 1983-12-20 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 7801242 Medline TA: J Appl Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 1211-8 Citation Subset: IM |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adolescent Adult Consciousness Humans Male Pulmonary Ventilation Respiration* Tidal Volume Time Factors Work of Breathing* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Firing profile of diaphragm single motor unit during hypercapnia and airway occlusion.
Next Document: Time course of airway hyperresponsiveness induced by ozone in dogs.