[Study of the cardiovascular system in long-term space flights].

During the Salyut-6 space flights cardiac bioelectrical and mechanical activity, blood content and tone of cerebral and limb vessels, systemic arterial and venous pressure were measured in 10 primary crewmembers. The measurements were taken at rest and during LBNP and ergometry tests. The study has shown that the circulation changes are adaptive reactions of the body to a new environment, particularly weightlessness. Cardiovascular responses to the provocative tests were changes and more marked, probably, due to blood redistribution.