The human body is an amazing thing. For each one of us, it’s the most intimate object we know. And yet most of us don’t know enough about it: its features, functions, quirks, and mysteries. Our series The Body explores human anatomy, part by part. Think of it as a mini digital encyclopedia with a dose of wow.
Your tongue is good for a lot more than eating an ice cream cone or a giving a rude gesture during a moment of road rage. Not only does the tongue play a crucial role in your sense of taste, it’s important to breathing, swallowing, speaking, and singing.
Your tongue is actually made of eight interwoven, striated muscles that can move in any direction. It’s thick with glands and fat, and covered in a mucus membrane, which is why it’s always moist. Here, Erich Voigt, otolaryngologist and clinical associate professor at NYU Langone Medical Center, reveals to Mental Floss some underappreciated facts about the tongue.
1. TASTE RECEPTORS ARE CONCENTRATED ON THE TIP OF YOUR TONGUE …
They're also clustered along the sides and at the back; the middle of the tongue is the least receptive area. The tongue is covered with tiny nodes called papillae, which house your taste buds, as well as the serous glands, required for the act of tasting.
2. … AND THE IDEA THAT THE TONGUE HAS FLAVOR ZONES IS A MYTH.
That tongue map with different zones for different flavors that we all grew up learning? It's wrong. All taste buds are capable of detecting the five types of taste (sweet, sour, salty, bitter, and savory), though different receptors are more responsive to different flavors.
3. BLAME YOUR KID'S "SWEET TOOTH" ON HER TONGUE.
If you’ve ever wondered why you used to be able to enjoy a mouthful of sugar and now find candy too sweet, it’s probably because the types of taste buds you have change as you age. Kids' taste buds are more sensitive to sweet tastes than adults' tongues are. “It explains why children really enjoy sweets and candies, as compared to adults who may enjoy more complex flavors and spices,” Voigt says. There are likely evolutionary reasons for this sweet, er, tongue.
4. THE THYROID GLAND DEVELOPS IN THE TONGUE.
When a fetus is developing, says Voigt, the embryonic thyroid gland “starts in the tongue and then descends down the neck as a child forms.” In certain rare cases, the thyroid doesn’t drop, and can be located in the base of the tongue at birth. This is called a lingual thyroid, and requires removal and medication. This condition may not be caught right away—usually doctors don’t notice until symptoms of hyperthyroidism turn up, or a goiter, a swelling of the thyroid, appears.
5. IT'S NOT THE STRONGEST MUSCLE IN THE BODY.
It's a common misconception, says Voigt. But depending on how you measure strength, that title could be more justifiably claimed by the heart, the jaw bone's masseter, or the gluteus maximus in your butt. While the tongue is very strong because “it’s made up of many muscles both intrinsic and extrinsic,” Voigt says, its notability lies in its flexibility. The tongue has unique biomechanics—unlike other muscles, it doesn't surround any supporting bones, and it needs to be able to make three-dimensional changes in shape to handle all the speaking, eating, and swallowing we require of it.
6. THE ABILITY TO DO TONGUE TRICKS ISN'T GENETIC.
Can’t make a fleur de lis with your tongue? Not your mom’s fault. It turns out that the longstanding belief that the ability to roll, flip, and bend your tongue is a genetic trait is not true. John McDonald, an evolutionary biologist at the University of Delaware, recently debunked this myth in an NPR interview. If such an ability were genetic, then identical twins would both be able to do it, which is not the case, as was shown in a 1952 study by geneticist Philip Matlock.
7. IT HAS SOME REAL NERVE.
Actually, it has two, and they're distinctly different, which Voigt says is atypical. “The tongue has very unique nerve innervation. The anterior [forward] two-thirds gets a different nerve from the posterior [back] one third,” he says.
8. YOUR TONGUE CAN LOOK LIKE A MAP…
Geographic tongue is an unusual condition in which a loss of the tiny papillae that normally cover the tongue’s surface creates irregular raised, red patches on the tongue that can resemble continents or islands on a map. Doctors don’t understand the causes of this bizarre condition, though stress, allergies and eating habits may be responsible. Voigt says, in some cases, those patches “might even grow hair.”
9. … AND GET A SEXUALLY TRANSMITTED DISEASE.
The human papillomavirus (HPV) is a sexually transmitted disease that typically afflicts the genitals of humans. It can result in genital warts and is a risk factor for cervical cancer. Unfortunately, says Voigt, “The base of the tongue is one of the increasing forms of cancer due to infection from HPV, which is spread there through oral sex.” Other forms of tongue cancer can result from drinking alcohol, chewing tobacco, and chewing betel nut.
10. STICKING OUT YOUR TONGUE ISN'T ALWAYS RUDE.
In Tibet, sticking out your tongue is a considered a polite greeting between two people when they meet. And among the Maori people of New Zealand, sticking out the tongue is part of a ritual called a haka, where men stick out their tongues in a simulated war dance to intimidate the enemy.