[External respiration, pulmonary gas exchange and energy expenditure in weightlessness].

This paper summarizes the data on external respiration and energy expenditures of men exposed to zero-g for 185 days and to 1/6 g on the lunar surface reported by Soviet and foreign authors. The paper also discusses factors that may be responsible for a higher level of gas exchange processes at reduced g.

[Results of studying the hemodynamics and phase structure of the heart cycle in a functional test with lower body negative pressure exposure on an 140-day flight on the Saliut-6 station].

The two members of the 140-day permanent Salyut-6 space flight were exposed to 5 LBNP tests at -25 and -35 mm Hg for 2 and 3 min, respectively. Circulation responses to the LBNP tests were measured with respect to the heart rate, arterial pressure, chronocardiogram and cardiac output. As compared to the preflight data, inflight responses were characterized by a greater tachycardia, preload insufficiency, and vascular tone in the absence of orthostatic intolerance.

[Changes in the body weight of cosmonauts during a 140-day space flight].

During 140-day space flight body mass changes of the Commander and Flight-Engineer were measured. No correlation between body mass losses and flight duration was found. Greatest body mass losses occurred on MD 44--59 in Commander (2.

[Study of hemodynamics and the phase structure of the cardiac cycle of members of the second crew of orbital station "Salyut-6" at rest].

During the 140-day flight of the Salyut-6 station cardiovascular examinations were carried out at rest. They showed blood redistribution and hyervolemia of the upper body. They also demonstrated increases in the circulating blood volume and pulse blood filling of cerebral vessels, development of the phase preload syndrome and simultaneous decrease in blood filing of leg vessels.

[Effect of antiorthostatic hypokinesia and space flight factors on changes in crural volume].

The purpose of the present investigation was to assess, using a specially built sensor, variations and level of fluid redistribution as well as atrophic changes in leg muscles of test subjects exposed to prolonged head-down tilt and cosmonauts in a real space flight. Hypokinetic test subjects were examined before, during and after head-down tilt, whereas cosmonauts were examined before and during flight. The results obtained show that a change in the hydrostatic component of blood pressure is followed by displacement of a substantial fluid volume (about 7%).

[Experimental evaluation of the relationship between lesser circulation engorgement, the state of water-salt metabolism and the orthostatic reactions in man].

In 12 series of short-term (4.5 hour) experiments the exposures that influenced the blood distribution relative to the long axis of the body (postural changes, lower body excessive pressure, lower body negative pressure, axial loads) were studied. A close correlation between the blood flow in lung capillaries, water losses and orthostatic responses was established.