In the history of medicine, during the nineteenth century, two currents of physiology emerged with different epistemological frameworks: the analytic current and the synthetic current. One of them, the school of synthetic physiology, which picks up the tradition of the Nervism Current that arises in Russia, considers the nervous system as the coordinating axis of all pathophysiological states in the body. Within the framework of this school, Pavlov’s theory of conditioned reflexes plays an important role in understanding not only the phenomena of learning in individuals but also the pathological processes that are created during ontogeny. Subsequently, Pavlov’s disciples present new concepts that allow us to understand how functional nerve centers are generated in the organism that dominate over other reflexes or centers. These concepts also offer new interpretations of how the health-disease process occurs in complex organisms and how language, cognition, and emotion participate in these pathophysiological processes. Finally, with the theory of functional systems, a conceptual model is presented that anticipates the birth of cybernetics, and that involves concepts of anticipation, self-correction, and self-organization in systems. All these concepts and theories have applicability and clinical utility, both diagnostic and therapeutic, in the fields of medicine and neural therapy.