24 REFLECTOR DOCTRINE

Reflexes (from the Latin. Reflexus - "turned back, reflected") are the reactions of the body, excited by the central nervous system during stimulation of receptors by agents of the internal or external environment; found in the emergence or transformation of the functional activity of organs and the whole organism.

The concept of "reflex" was first put forward by the French philosopher R. Descartes. Even in the period of ancient medicine, the differentiation of human motor actions into “arbitrary”, causing the participation of consciousness in their realization, and “involuntary”, realized without the participation of consciousness, was revealed. The teachings of R. Descartes on the reflex principle of nervous activity is based on knowledge of the structure of involuntary movements. The whole process of nerve act, characterized by automatism and involuntariness, consists in the initiation of tactile apparatus, conducting their effects along the peripheral nerves to the brain and from the brain to the muscles.

The main contribution to the study of reflex and reflex apparatus was made by C. Bell and F. Magendy. They found that all tactile (afferent) fibers enter the spinal cord as part of the posterior roots, while efferent (motor) fibers leave the spinal cord as part of the anterior roots. This discovery allowed the English doctor and physiologist M. Hall to argue for a clear opinion about the reflex arc and to widely apply the theory of reflex and reflex arc in the clinic.

By the second half of the nineteenth century. knowledge of common elements in the structures of both reflex (involuntary) and voluntary movements, which are attributed to the results of mental activity of the brain and contrasted with reflex ones, is expanding.

I. M. Sechenov in his work “Reflexes of the brain” (1863) stated that “all acts of conscious and unconscious life according to the mode of origin are reflexes”.

He argued the consideration of the universal significance of the reflex principle in the activity of the spinal cord and brain for involuntary, automatic, and voluntary movements associated with the participation of consciousness and mental activity of the brain. The scientific work of C. Sherrington, N. E. Vvedensky, A. A. Ukhtomsky, I. S. Beritashvili proved the judgment of coordinating and combining the reflex reactions of some arcs in the functional activity of organs based on the interaction of excitation and inhibition in reflex centers. In clarifying the mechanisms of reflex activity, an important role is played by the study of the histological organization of the nervous system.

Spanish histologist S. Ramon-i-Kahal scientifically proved that a neuron is a structural and functional unit of the nervous system.