POSTURAL REACTIONS OF CIRCULATION AND ITS REGULATION DURING SIMULATEDWEIGHTLESSNESS

The extention and intensification of space exploration the influence o f weightlessness on human organism and the formation of a new level of adaptation. The studies of blood circulation is very important becaus e of freguent occurance of cardiovascular disorders in the middle age subjects. In connection with extention and intensification of space ex ploration the influence of weightlessness on human organism and the fo rmation of a new level of adaptation mechanisms acguires a special sig nificance (5, 9, 10). The data obtained in recently undertaken model e xperiments (1, 5, 10), and also during space flights (5, 9) indicate t hat weightlessness in many ways affects various physiological systems of organism, and first of all cardiovascular system with the developme nt of reflex, humoral and metabolic reactions. It also indicates, that the changes in functioning of cardiovascular system brings about the discruption of its regular responses, which is foremost expressed in d ecreased antigravitational response, which manifests itself in lowered orthostatic stability (2, 4, 6). It is worth mentioning, that the cha nges during previous investigations of haemodynamics were mainly carri ed out with the subjects under forty, therefore agerelated specific fe atures of blood circulation system response are described in a few art icles (5, 8). The studies of the kind are especially important because of frequent disorders such as heart and brain vessels atherosclerosis , hypertension in the middle age, which can to a great extent complica te and affect the ''acute'' period of adaptation to weightlessness and readaptation process.