I.B. Ushakov, O.G. Sorokin

The organism is a complex system. All its structural elements work and interact in performing their specific functions. Generality of the mechanisms linking various structural elements of organism into single integrated system, involves non-specific nature of their work. Research of these processes was conducted at the level of whole organism as most accessible for study. In several species of animals and in humans were established periodic discrete changes of nonspecific adap-tive reactions to various influences. Surveys of people made it possible to identify the relationship of adaptation state of organism with indicators of regulatory systems. The established regularity made it possible to find the biological optimum of organism functioning. Based on evaluation of indicators of regulatory systems and comparison to the biological optimum, a model was estab-lished to describe these systems - work, depending on the adaptation state of the organism. Results of examination of people in various physiological conditions, diseases, physical and psychical loads allowed reaching the following conclusion. The functioning of organism as a whole system is based on implementation of structural elements on different levels that are operating on the principle of object pooling. Pools consist of reserve structures with different threshold of activation, the inclusion of which depends on non-specific characteristics of irritants. Energy resources of the organism are crucial to the implementation of these processes. The formation of reserve structural elements into separate pools is associated with the organism-s need to minimize power consumption for effective and adequate use of its structures in order to maintain homeostasis in a changing environment. Established on the organism level patterns may lie in the base of principle of functional construction of the organism, and cover all of its structures, merging them into one coherent system.