The reproductive system implements the fundamental biological function of preserving and maintaining the process of life. Gametogenesis provides reproduction of the whole organism, and steroidogenesis, through the influence of sex hormones on the process of gene transcription, is involved in the cell reproduction of private protein substances in this organism. Reproduction is the main and most complex property of life. The concept of physiology and pathology of the sex glands described in this work is based on a synthesis of facts and principles of fundamental biomedical sciences with the results of our own clinical studies on the etiopathogenesis of disorders of male reproductive function, on understanding the relationships between the sexual and hormon-secreting cells in gonads from the perspective of the general biological role and ontogenesis of the sexual systems, theories of functional systems. The productive subordination of sex and somatic cells (without it any life is impossible in general biological terms) can be clearly seen during ontogenesis both in physiology and in the genesis of genital gland dysfunction.