Background. The tongue is a powerful muscular organ with a variety of functions and the ability to influence many systems of the human body, which is due to the peculiarities of its embryogenesis, the proximity of many anatomical structures, rich innervation and connection with many parts of the brain. Functional changes of the tongue muscles can be associated with various pathological conditions. Thus, systemic disorders secondarily involve the tongue, and local changes in the tongue (tongue dysfunction, tumors,changes in the mucous membrane in old age and with existing somatic diseases, obstructive sleep apnea syndrome and emotional can develop into systemic diseases. Tongue has embryological and functional relationship with the occipital region and the hyoid bone, which develop from the second gill arch. In addition, anatomically, the tongue is also interconnected with the hyoid bone and, therefore, with hyoid muscles and muscles of the mouth bottom. Aim. To determine the significance of the functional features of human tongue in the etiopathogenesis of dysfunctional states of the muscular, respiratory and other systems and the psycho-emotional sphere of the human body. Material and methods. Was analyzed the researchers results from available literature sources from the "Elibrary" and "Pubmed" platforms, including patents and scientific articles of domestic and foreign authors. Results. The paper presents data from literature sources on anatomical and functional relationships with human body systems. The correct physiological localization of the tongue in the oral cavity is described, the advantages of this position are given. Conclusions. It is well known that the tongue participates in speech formation, chewing, swallowing. However, the facts of the influence of the position and functional features of the tongue during breathing, the formation of structures of the maxillary system, the maintenance of posture and muscle balance of the human body, facial function, in the emotional sphere are interesting.