Fundamentals of anatomy and physiology of the olfactory tract and possibilities of its topodiagnostic damages by means of olfactory evoked potentials
Introduction: The recognition of the influence of olfactory stimuli on the olfactory organ aims at identifying damages within this area, diagnosing many diseases and smell impairments such as parosmia, hyposmia, anosmia and cacosmia. This work is focused on presenting current knowledge on fundamentals of anatomy and physiology of the olfactory tract and possibilities of its topodiagnostic damages by means of olfactory evoked potentials. Definition of smell: In the surrounding world the sense of smell operates through a series of sensations, which are described as smell. The smell of a compound depends both on the structure of a carbon chain and a ring, and on the presence and type of functional groups and their arrangement in a molecule. Defining a smell on the basis of its structure can be particularly difficult. In future the answer should be found in the electron theory of organic compounds structure. Anatomy and physiology of the sense of smell: The receptors, which are responsible for receiving olfactory sensations, are located in the nasal cavity, the upper part of the nasal septum, the root and anterior portion of the superior nasal concha. In adults the olfactory epithelium covers 1-3 cm2 of the mucosa in each nasal passage. The olfactory tract comprises three neurons, whereas the cortical centre is situated in the hippocampal gyrus and amygdalic nucleus of the temporal lobe. Olfactory sensations are perceived via the olfactory epithelium, which is often accompanied by additional stimulation of endings of the trigeminal, facial, glossopharyngeal and vagus nerve. Diagnostics of the sense of smell: Registering olfactory evoked potentials is an objective method of testing the sense of smell by detecting changes in bioelectrical functions of the brain. In Poland this method is quite modern and, in fact, is seldom used because of the lack of an appropriate batcher. Conclusion: Uniform standards and methodology of the study should lead to further implementation of this objective testing method in topodiagnostics of smell disorders.