They are a part of our lives, whether we think about them or not. Taste buds are what make us cringe when we’re fed something sour, smile when our sweet tooth is satiated, and help us pinpoint our favorite foods. How does this system of sensory objects on your tongue translate the flavors of food and determine which are bad and which we want more of?
Without taste buds, human beings would have no notion of the five basic tastes: salty, sweet, sour, bitter, and umami. What’s most peculiar about them, however, is that while there is an average of 10,000 taste buds on every tongue, nobody has the same taste buds they were born with. Replaced about every two weeks, this abundance of small bumps is the prime reason our brains register that a hot dog is salty or chocolate ice cream is sweet.
The science of it is relatively simple, though there may be an additional unexpected factor involved in the process of taste.
The bumps of your tongue
Every tongue is covered in visible bumps known as papillae or taste papillae. These bumps are composed of taste buds and serve four different purposes based on which of the following categories it belongs to: taste, fungiform, circumvallate, and foliate. The former of these, taste papillae, are located beneath the mucous membrane and are responsible for increasing the surface area of the tongue to intensify individual tastes.
Fungiform papillae are the most common and do more than just sense taste. Located at the tip and around the edges of the tongue, fungiform papillae also sense touch and temperature. Toward the back of the tongue, found in a “V” formation, are circumvallate papillae. As the name implies, they are responsible for washing the substances responsible for taste into sensory cells. Finally, foliate papillae are found on the rear edges of the tongue and only further enhance the strength and prominence of the taste.
Receptors of taste
The taste buds that comprise the different papillae are nothing more than a combination of basal, columnar, and taste receptor cells. Receptor cells may be the most active as they are responsible for binding their proteins with the chemicals of the food we eat.
Different types of receptor cells are coated with a protein intended to attract a specific type of chemical that is linked to one of the five basic tastes. When the receptor cell identifies the chemical it binds with, it will send a signal through a neural network to the brain via microvilli, or microscopic hairs on every taste bud.
Despite what some may believe and continue to spread around as fact, there are no specific areas of the tongue responsible for a particular taste. Instead, it’s the taste receptors scattered across your tongue that pinpoint the proper flavor.
How the nose is involved
There is more to taste than just the tongue. Lining the uppermost part of the human nose are olfactory receptors that are responsible for sense of smell. The message that’s sent also helps to further hone in on the tastes touching your tongue.
When you chew food, a chemical is released that travels to the upper part of your nose and activates the olfactory receptor. These receptors work in conjunction with the receptors on taste buds to help the brain recognize the type of taste. Involvement of the nose explains why a cold or allergies can hinder one’s sense of taste, leaving everything to be bland.
Taste buds and aging
As with anything else in the human body, advanced age can contribute to a decline in the number of taste buds on one’s tongue. In some cases, an elderly person could have half the number of taste buds as someone young and healthy. The older we get, the more likely we are to notice that certain tastes aren’t as strong as they once were.
The science of taste
Our sense of taste is surprisingly complicated. From what we eat, to how we eat it, to the functioning of our other systems, there’s a lot that goes into it. But hopefully, this rundown offered a good sense of how it works and why different foods might seem blander as we grow older.