Journal of Applied Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 70: 1907-1911, 1991;
8750-7587/91 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Engel, L. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Engel, L. A.

Journal of Applied Physiology, Vol 70, Issue 5 1907-1911, Copyright © 1991 by American Physiological Society

ARTICLES

Effect of microgravity on the respiratory system

L. A. Engel
Thoracic Medicine Unit, Westmead Hospital, Sydney, New South Wales, Australia.

Because the pleural pressure gradient and regional distribution of pulmonary function are gravity dependent, substantial changes may be expected during weightlessness. Although very few measurements have been made during spaceflights, a number of observations during brief periods of weightlessness inside aircraft flying with parabolic trajectories confirm these predictions. Single-breath N2 washouts suggest a marked reduction in the inequality of ventilation distribution seen at 1 G. Similarly, inferences made from cardiogenic oscillations during single-breath washouts suggest a greater uniformity of perfusion during weightlessness. This is supported by changes seen on chest radiographs as well as by more direct measurements of regional blood flow distribution using radioactive iodine-labeled macroaggregates. Vital capacity is only slightly reduced, but functional residual capacity decreases by approximately 10% and maximum expiratory flow rates are slightly decreased, especially at low lung volumes. Weightlessness decreases abdominal girth, increases abdominal compliance, and substantially increases the abdominal contribution to tidal volume during resting breathing. Despite these changes, there does not appear to be any alteration in the temporal pattern of breathing. However, the deposition of inhaled medium-sized aerosol particles is substantially reduced, as predicted by model analyses of gravitational sedimentation. Virtually all these observations describe effects at the very onset of weightlessness. Practically nothing is known of slower functional changes and adaptations to prolonged weightlessness. Systematic repeated measurements during manned spaceflights will hopefully begin to provide some information on this subject in the near future.


This article has been cited by other articles:


Home page
 J. Appl. Physiol.Home page
D. Bettinelli, C. Kays, O. Bailliart, A. Capderou, P. Techoueyres, J. L. Lachaud, P. Vaida, and G. Miserocchi
Effect of gravity on chest wall mechanics
J Appl Physiol, February 1, 2002; 92(2): 709 - 716.
[Abstract] [Full Text] [PDF]

Home page
 J Am Coll CardiolHome page
M. Guazzi, P. Agostoni, and M. D. Guazzi
Modulation of alveolar-capillary sodium handling as a mechanism of protection of gas transfer by enalapril, and not by losartan, in chronic heart failure
J. Am. Coll. Cardiol., February 1, 2001; 37(2): 398 - 406.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
P. Vaida, C. Kays, D. Riviere, P. Techoueyres, and J.-L. Lachaud
Pulmonary diffusing capacity and pulmonary capillary blood volume during parabolic flights
J Appl Physiol, April 1, 1997; 82(4): 1091 - 1097.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online