Analysis of the concepts of pain since ancient times to the present day is given in a number of extensive reviews. Currently there is no universally accepted definition of pain. In our country the most widespread definition of pain given by Academician ii K et al (1976), where the pain is described as "integrative function of the body that mobilizes a variety of functional systems to protect the body from the effects could undermine the factors and includes components, such as consciousness, memory, motivation, emotion, autonomic, somatic and behavioral responses. " Some authors define pain as an unpleasant sensation. Thus, according to vn Stock (1988), for example, is described as any painful sensation in the head. jj Bonica (1985) defines acute pain as "a constellation of unpleasant sensory, emotional and spiritual experience and accurately related autonomous, physical and behavioral reactions induced by injury or acute illness.

" By analyzing the definition of pain given by various authors, Yu P (1985, 1986) distinguishes four main groups. The first group of scientists defines pain as an unpleasant feeling that is characterized by tissue damage or a threat. The second group defines pain as an affective state of the organism with the inclusion of emotional and vegetative reactions Still others define pain as a motivational state created by a form conduct aimed at eliminating the causes of pain. Finally, a number of scientists in the definition of pain emphasizes that it will mobilize the various functions of the organism to protect from damage. The clinic is regarded pain as an unpleasant sense of causing a patient pain of varying intensity – from unbearable to tolerable (VA Kurshev, 1984). Pain is a reflection of objective reality and indicates the presence of changes in peripheral and central nervous system. It is regarded as a consequence of the integrative functions of the body, because the nociceptive effects of mobilized consciousness, memory, motivation, emotion, somatic and behavioral responses. Pain as a psycho-physiological phenomenon, according to A. Waldman (1980), consists of emotional feelings and reactions in the form of motor-autonomic and humoral manifestations of identical stress reactions arising in adverse effects. In our opinion the same, the pain – this is a model, worked out the evolutionary process that occurs when you step on the body of nociceptive factors or weakening Pain system includes perceptual (awareness, perception of pain), autonomic, emotional, behavioral, motor, antinociceptive components and aims to protect the body from injury and pain management.