[Postural hemodynamic shifts following short-term space flights]

Variations in the pulse blood content and tone of cerebral vessels, vertebrobasilar system, lungs and legs during the antiorthostatic tests were examined rheographically in 14 cosmonauts after 8-day space flights. The results of adaptation of the vascular system to zero-g which included smaller changes in hemodynamic parameters of the hemispheres and vertebrobasilar system during postflight tests were seen during the first days of the recovery period. Regional hemodynamic parameters returned to the preflight level within 3 to 14 days postflight. The vascular response to the head-down tilt at --15 and --30 degrees was the most informative. This led to the recommendations concerning modifications of antiorthostatic tests to be used in the selection of space crewmembers for short-term flights.