O taste it is an important sense of the human body that allows us to recognize flavors, in addition to feeling the texture of ingested food. The tongue is the main organ of this sense and is able to differentiate between sweet, salty, bitter, sour and umami tastes. The latter is the flavor produced by some types of amino acids.
At tongue, mainly, there are found several structures called taste buds. They are formed by epithelial cells with neural properties and are responsible for the perception of flavors. The taste buds are located mainly in the region of the papillae, varying in quantity for each type. In filiform papillae there are no taste receptors, unlike fungiform, foliate and circumvallate papillae. In these last ones, the buttons are presented in greater quantity when compared to the others.
Previously, it was believed that these buds were arranged by areas on the tongue, with each area being responsible for the sensation of a different flavor. In view of this thought, a very widespread scheme emerged in textbooks (see the drawing below) and which has persisted to this day.
For a long time, the above scheme was used in textbooks. Today it is known that he is not correct
Today we know that the taste buds are spread over the dorsal surface of the entire tongue, in the region of the palate, epiglottis, pharynx and larynx, in a way that allows the perception of taste in any of these parts. Therefore, the scheme shown above should no longer be used.
You taste receptors are stimulated thanks to chemical substances present in foods that trigger the nerve impulse. Sweet, bitter and umami tastes are perceived by virtue of membrane receptors coupled to G proteins. Already salty and acid, to be perceived, depend on ion channels. Therefore, it is noticed that there are different specialized cells for the perception of a certain taste.
After the perception of these signals, the nervous impulse must be taken to the central nervous system, where it will be interpreted. Recent research shows that each flavor activates a specific region of the taste cortex, with the exception of sour, which apparently is not interpreted there.
Some diseases can impair the taste buds, as well as some medications, especially those used chronically. Chemotherapy and radiotherapy are also related to loss and changes in this regard, but these effects can be reversed after treatment.
Curiosity: Did you know that temperature can influence the taste of food? When we have colder food, we notice the sour taste better. When food is at a higher temperature, we perceive it to be sweeter. Thus, chocolates that are kept in the refrigerator are less sweet than those consumed at room temperature.
By Ma. Vanessa dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/oscincosentidos/paladar.htm
