Lung volumes during sustained microgravity on Spacelab SLS-1Gravity is known to influence the topographical gradients of pulmonary ventilation, perfusion, and pleural pressures. The effect of sustained microgravity on lung volumes has not previously been investigated. Pulmonary function tests were performed by four subjects before, during, and after 9 days of microgravity exposure. Ground measurements were made in standing and supine postures. Tests were performed using a bag-in-box and flowmeter system and a respiratory mass spectrometer. Measurements of tidal volume (V(sub T)), expiratory reserve volume (ERV), inspiratory and expiratory vital capacities (IVC, EVC), functional residual capacity (FRC), and residual volume (RV) were made. During microgravity, V(sub T) decreased by 15%. IVC and EVC were slightly reduced during the first 24 hrs of microgravity and returned to 1 g standing values within 72 hrs after the onset of microgravity. FRC was reduced by 15% and ERV decreased by 10-20%. RV was significantly reduced by 18%. The reductions in FRC, ERV, and V(sub T) during microgravity are probably due to the cranial shift of the diaphragm and an increase in intrathoracic blood volume.
Document ID
19950011389
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Elliott, Ann R. (California Univ. La Jolla, CA, United States)
Prisk, Gordon Kim (California Univ. La Jolla, CA, United States)
Guy, Harold J. B. (California Univ. La Jolla, CA, United States)
West, John B. (California Univ. La Jolla, CA, United States)
Date Acquired
August 16, 2013
Publication Date
August 1, 1994
Publication Information
Publication: ESA, Proceedings of the Fifth European Symposium on Life Sciences Research in Space