Taste Buds: Types, Characteristics And Functioning
The senses refer to the physiological mechanism of sensation, and allow us to obtain information about what is happening around us, as well as certain internal states of the organism itself. The sense of sight seems to be the most important of all because, with 130 million photosensitive cells distributed in each eye, these complex devices allow us to locate our figure and actions in 3 dimensions, with everything that this entails.
Although smell and taste seem less relevant than sight itself, can you imagine how human beings could have evolved without a sense that warns us that what we are ingesting is dangerous? Disgust is a primal sensation present in many animals, since the regurgitation of a toxic or harmful element, in many cases, can save the individual’s life.
So that, Taste buds and the sense of taste in general play a much more important evolutionary role than one might expect initially. If you want to know everything about taste buds, continue reading.
Taste buds are defined as a set of sensory receptors, specifically called taste receptors They are found in the tongue and are the main promoters of taste, that sense that allows us to enjoy food and discriminate those elements that are not edible. The papilla refers to the skin fold that we have on the tongue, but what really encodes the “understanding” of flavor are the taste buttons found on it.
On average, a healthy adult individual has about 10,000 taste buds distributed across taste buds, which regenerate approximately every 2 weeks. Unfortunately, as time passes, these structures degrade. An elderly person has half as many buttons as a young person, and that is why it is sometimes more difficult for older people to identify certain flavors. Smokers have the same problem, since exposure to tobacco smoke decreases the proportion of these cells.
What are taste buds?
As we have mentioned in previous lines, The taste buds are the sensory cells present in the papillae responsible for transmitting the signals that translate into taste itself Each taste bud is formed by the association of about 50-100 cells, known as taste receptor cells (TCR). In mammals, taste buds are widely distributed throughout the tongue, soft palate, and oropharynx.
These curious buttons have an ovoid shape, between 50 and 60 microns high and 30 to 70 microns high. In each taste bud we find 3 cell types, whose characteristics and functions are different. We present them to you in the following list:
In general, Two possible neuronal models are described to explain the functioning of taste buds To keep things simple, we will say that the first postulates that a gustatory receptor cell itself detects a single basic modality of taste and is innervated by individual nerve fibers that transmit the signals of that single modality (this is known as a marked line). Once these cells are stimulated, the information is sent as an action potential to the brain.
In the other model, known as a computational model, individual taste receptor cells detect one or several modalities of taste, and the fibers transmit signals from multiple modalities at once. It is, therefore, a more intricate complex of activity than the previous case.
Types of taste buds
Once we have explored the world of taste buds, we can return to the taste buds. It is time to clarify that there are 4 types of them, and we will briefly tell you about them below.
1. Fungiform papillae
They are called that because they are shaped like a mushroom, neither more nor less. They are rare in many animals and They are located on the tip of the tongue It is interesting to know that they are not only found in humans, but are also present in other mammals. They are much more numerous in carnivores and of reduced appearance in bovids and horses.
Composed of a head and a pedicel, this type of papillae are very visible, due to the reddish color given by the blood vessels that supply them. These types of papillae are much more stimulated in old age and the early stages of development, since They are mainly specialized in the processing of sweet flavor According to various sources, this type is the most represented type of gustatory nature in the human species.
Also known as circumvallate papillae, They are a large and underrepresented type of papilla, but with vital importance: they detect the bitter taste These are found in a number of 11 in a V-shaped arrangement on the back of the tongue, near the tonsils, and can be clearly seen as “bumps” or lumps.
In addition to their detection of bitter flavors, they also have a series of minor salivary glands that help the digestion process. We say that they are the most important papillae because they detect the bitter taste, which, in many cases, can represent dangerous ingestion. In addition to this, being located on the farthest part of the tongue, they contribute to the gag reflex.
3. Filiform papillae
The filiform papillae have a conical/cylindrical shape and end in a crown of filaments, which gives them their characteristic name. They are distributed over the entire surface of the tongue, always arranged in parallel series that go obliquely from the groove in the middle of the tongue to the edges of it. They are the most abundant type within the language but, curiously, their function is not to interpret flavors.
The filiform papillae act as a covering for the tongue. They make this present a rough and abrasive structure, which helps us clean the mouth, swallow and speak. In simpler terms, they act as physiological “handholds” in multiple oral processes. Its thermal and tactile function is stimulated, above all, during the adult period of the individual.
4. Foliate papillae
The foliate or foliaceous papillae They appear as short vertical folds, present in parallel on both sides of the back of the tongue These appear in the form of symmetrical ridges, in a number of 4-5 folds, depending on the individual. Its receptors capture salty flavors.
Let’s do a little final review, since we have introduced a lot of terminology that requires a “mental map.” Imagine your own language in the mirror At the tip, the fungiform papillae are agglutinated, which are responsible for interpreting sweet flavors.
If you go back, near the bell, you will find 11 large papillae arranged in a V shape, which are responsible for processing the bitter taste and promoting vomiting or when the ingested element could be harmful to the body.
On the sides and looking at the base of the tongue, we will find a series of folds, in which the foliated papillae are found These are responsible for capturing the salty flavors.
Even so, as we have seen previously, each taste bud contains multiple cells responsible for identifying different types of flavors and, according to the computational model, each button would send information of more than one flavor to the relevant nerve ending In that case, the “taste map” described here would be of little use to us, since it is postulated that each papilla may contain all or some of the cells that interpret certain flavors. Be that as it may, the lingual map helps to understand the arrangement of the types of papillae and give us a general idea of their function.
Summary
As you may have read in these lines, the world of taste buds gives a lot to talk about. There are certain discrepancies and debates, since the truth is that, even today, we do not know some of the particularities of the sense of taste
Even so, it is clear that this has been essential for the development and permanence of the human species over time. Taste buds have allowed us to discriminate dangerous foods from nutritious ones, allowing us to develop physically thanks to adequate caloric intake. In the human body, every cell counts.
