Physiology studies the functions of the various organs and systems, along with the nature of their regulation in supporting the functioning of the body as a whole. The nervous and endocrine systems respond to stimuli and causality plays a key role in their activity. The physicochemical conditions of internal body fluids provide the background and serve as active modulators of their regulatory functions. The formation of local regulatory molecules (autacoids) is based largely on probabilistic events. There are grounds for the suggestion that the appearance of regulatory molecules during the formation of regulatory systems in cellular evolution was based on statistically probable quantum events: random appearance in cells during the metabolism of peptides and lipids, hydrolysis of larger molecules to fragments, and quanta which acquired physiological activity as regulators of functions. In terms of their adaptive value, Darwinian mechanisms recorded these processes in the genome as the mechanism of polypeptide synthesis by reading the genome was fixed. The formation of multicellular organisms was accompanied by the establishment of regulatory systems and their integration under the aegis of the nervous system. © 2012 Springer Science+Business Media, Inc.