Taste the feeling that arises when exposed to a certain chemical substances soluble in water, on specific taste receptorsthat are located in different parts of the language. The taste is composed of four main simple taste sensations: sour, salty, sweet and bitter. All other variations of taste are the result of a combination of primary sensations. Different areas have different sensitivity to flavouring substances. The tongue has the greatest sensitivity to sweets, the tip and sides - to the salt, the sides of the tongue to the sour and the root of the tongue is the most sensitive to bitter.
The mechanism of perception of flavouring substances associated with a specific chemical reactions on the border of the matter - the taste Bud. Assume that each receptor contains highly sensitive protein substances, falling apart when exposed to certain flavor substances. The excitement from the palate is transmitted to the Central nervous system by specific conduction paths consisting of fibers language-pharyngeal nerve (n. glossopharyngeus ) and drum strings (chorda tympani). They originate from a variety of receptors language and sent to the medulla, then taste the path passes through the reticular formation, through the thalamus in the cerebral cortex in the region nalandaway tires (operculum Rolandi). Set the taste buds of pathways and cortical representation of taste perception is designated as the taste analyzer. Tastes may vary with age and subverted in some diseases.
Disorders of taste can occur with the defeat of flavouring receptors of language, pathways and taste centre. They arise when heavily coated tongue, inflammation, injuries, scars on it, and when the nerve damage and Central routes. Disorders of taste are in the brain tumors, trauma, facial paralysis, radiation sickness, as well as the nervousness (hysteria).
Disorders of taste are in the form of high taste - taste giperestesia (hyperemia), reduced taste - taste gipestesia (hypogeusia) or complete loss of taste - anesthesia (Agenzia). If dysgeusia (taste perversion) patients eat substances that cause aversion in healthy (lime, clay). If parageusia (paresthesias) have sensation of numbness, tingling of the tongue, not due to external irritation; they can be and when autosuggestion. Gustatory hallucinations occur in psychiatric patients and in the defeat of the temporal lobe of the brain.