Overview. Sulzman, Frank M. Life Sciences Division, NASA Headquarters, Code UL, 300 E St. SW, Washington, DC 20546
APStracts 3:0182A, 1996.
It has been known for many years that weightlessness induces changes in numerous physiological systems: the cardiovascular system declines in both aerobic capacity and orthostatic tolerance; there is a reduction in fluid and electrolyte balance, hematocrit and certain immune parameters; bone and muscle mass and strength are reduced; various neurological responses include space motion sickness, posture and gate alterations. These responses are caused by the hypokinesia of weightlessness, the cephalic fluid shift, the unloading of the vestibular system, stress and the altered temporal environment.

Received 1 March 1996; accepted in final form 3 April 1996.
APS Manuscript Number A319-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 16 April 96