10 Flexible Facts About the Tongue

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.

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Pierluigi Luceri, Flickr // CC BY-NC-ND 2.0
Two Human Toes Were Stolen From an Anatomy Exhibit
Pierluigi Luceri, Flickr // CC BY-NC-ND 2.0
Pierluigi Luceri, Flickr // CC BY-NC-ND 2.0

A 28-year-old New Zealand man walked into an anatomy exhibition with 10 toes and walked out with 12. We don't know why or how he did it, but the man stole two human toes from a Body Worlds display in Auckland last month, The New Zealand Herald reports.

The unnamed man appeared in court Monday and pleaded guilty to improperly interfering with the corpse "of an unknown person" and purloining two toes, which alone are valued at about $3800. The motivation for the human remains heist wasn't stated. (Fulfilling a dare seems a likely explanation, or maybe he's just a fan of The Big Lebowski.)

Whatever the reason may be, the story has a happy ending, at least: The digits have since been returned to their rightful place in the "Vital" exhibit, which explores the human body in motion. "Vital," which will remain open in Auckland until July 13, is one of several traveling exhibitions curated by Body Worlds. Two other Body Worlds exhibits are currently on view in the U.S., including "RX" (showcasing the effects of disease) in Toledo, Ohio, and "Animal Inside Out" (an "anatomical safari") in Richmond, Virginia.

The bodies, all of which are donated for exhibition purposes, are preserved via plastination, a process that "replaces bodily fluids and soluble fat in specimens with fluid plastics that harden after vacuum-forced impregnation," according to the Body Worlds website. More than 16,000 people around the world have signed up to donate their bodies after their deaths.

[h/t The New Zealand Herald]

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Illustration by Mental Floss / Images: iStock
11 Facts About the Appendix
Illustration by Mental Floss / Images: iStock
Illustration by Mental Floss / Images: iStock

Despite some 500 years of study, the appendix might be one of the least understood structures in the human body. Here's what we know about this mysterious organ.

1. THE ANCIENT EGYPTIANS CALLED IT THE "WORM" OF THE BOWEL.

The human appendix is small, tube-shaped, and squishy, giving ancient Egyptians, who encountered it when preparing bodies for funerary rites, the impression of a worm. Even today, some medical texts refer to the organ as vermiform—Latin for "worm-like."

2. THE APPENDIX SHOWS UP IN LEONARDO DA VINCI’S DRAWINGS.

The earliest description of a human appendix was written by the Renaissance physician-anatomist Jacopo Berengario da Carpi in 1521. But before that, Leonardo da Vinci is believed to drawn the first depiction of the organ in his anatomical drawings in 1492. Leonardo claimed to have dissected 30 human corpses in his effort to understand the way the body worked from mechanical and physiological perspectives.

3. IT'S ABOUT THE SIZE OF A PINKY FINGER.

The appendix is a small pouch connected to the cecum—the beginning of the large intestine in the lower right-hand corner of your abdomen. The cecum’s job is to receive undigested food from the small intestine, absorb fluids and salts that remain after food is digested, and mix them with mucus for easier elimination; according to Mohamad Abouzeid, M.D., assistant professor and attending surgeon at NYU Langone Health, the cecum and appendix have similar tissue structures.

4. CHARLES DARWIN THOUGHT IT WAS A VESTIGIAL ORGAN …

The appendix has an ill-deserved reputation as a vestigial organ—meaning that it allegedly evolved without a detectable function—and we can blame Charles Darwin for that. In the mid-19th century, the appendix had been identified only in humans and great apes. Darwin thought that our earlier ancestors ate mostly plants, and thus needed a large cecum in which to break down the tough fibers. He hypothesized that over time, apes and humans evolved to eat a more varied and easier-to-digest diet, and the cecum shrank accordingly. The appendix itself, Darwin believed, emerged from the folds of the wizened cecum without its own special purpose.

5. … BUT THE APPENDIX PROBABLY EVOLVED TO HELP IMMUNE FUNCTION.

The proximity and tissue similarities between the cecum and appendix suggest that the latter plays a part in the digestive process. But there’s one noticeable difference in the appendix that you can see only under a microscope. “[The appendix] has a high concentration of the immune cells within its walls,” Abouzeid tells Mental Floss.

Recent research into the appendix's connection to the immune system has suggested a few theories. In a 2015 study in Nature Immunology, Australian researchers discovered that a type of immune cells called innate lymphoid cells (ILCs) proliferate in the appendix and seem to encourage the repopulation of symbiotic bacteria in the gut. This action may help the gut recover from infections, which tend to wipe out fluids, nutrients, and good bacteria.

For a 2013 study examining the evolutionary rationale for the appendix in mammal species, researchers at Midwestern University and Duke University Medical Center concluded that the organ evolved at least 32 times among different lineages, but not in response to dietary or environmental factors.

The same researchers analyzed 533 mammal species for a 2017 study and found that those with appendices had more lymphatic (immune) tissue in the cecum. That suggests that the nearby appendix could serve as "a secondary immune organ," the researchers said in a statement. "Lymphatic tissue can also stimulate growth of some types of beneficial gut bacteria, providing further evidence that the appendix may serve as a 'safe house' for helpful gut bacteria." This good bacteria may help to replenish healthy flora in the gut after infection or illness.

6. ABOUT 7 PERCENT OF AMERICANS WILL GET APPENDICITIS DURING THEIR LIFETIMES.

For such a tiny organ, the appendix gets infected easily. According to Abouzeid, appendicitis occurs when the appendix gets plugged by hardened feces (called a fecalith or appendicolith), too much mucus, or the buildup of immune cells after a viral or bacterial infection. In the United States, the lifetime risk of getting appendicitis is one in 15, and incidence in newly developed countries is rising. It's most common in young adults, and most dangerous in the elderly.

When infected, the appendix swells up as pus fills its interior cavity. It can grow several times larger than its average 3-inch size: One inflamed appendix removed from a British man in 2004 measured just over 8 inches, while another specimen, reported in 2007 in the Journal of Clinical Pathology, measured 8.6 inches. People with appendicitis might feel generalized pain around the bellybutton that localizes on the right side of the abdomen, and experience nausea or vomiting, fever, or body aches. Some people also get diarrhea.

7. APPENDECTOMIES ARE ALMOST 100 PERCENT EFFECTIVE FOR TREATING APPENDICITIS.

Treatment for appendicitis can go two ways: appendectomy, a.k.a. surgical removal of the appendix, or a first line of antibiotics to treat the underlying infection. Appendectomies are more than 99 percent effective against recurring infection, since the organ itself is removed. (There have been cases of "stump appendicitis," where an incompletely removed appendix becomes infected, which often require further surgery.)

Studies show that antibiotics produce about a 72 percent initial success rate. “However, if you follow these patients out for about a year, they often get recurrent appendicitis,” Abouzeid says. One 2017 study in the World Journal of Surgery followed 710 appendicitis patients for a year after antibiotic treatment and found a 26.5 percent recurrence rate for subsequent infections.

8. AN INFECTED APPENDIX DOESN’T ACTUALLY BURST.

You might imagine a ruptured appendix, known formally as a perforation, being akin to the "chestbuster" scene in Alien. Abouzeid says it's not quite that dramatic, though it can be dangerous. When the appendix gets clogged, pressure builds inside the cavity of the appendix, called the lumen. That chokes off blood supply to certain tissues. “The tissue dies off and falls apart, and you get perforation,” Abouzeid says. But rather than exploding, the organ leaks fluids that can infect other tissues.

A burst appendix is a medical emergency. Sometimes the body can contain the infection in an abscess, Abouzeid says, which may be identified through CT scans or X-rays and treated with IV antibiotics. But if the infection is left untreated, it can spread to other parts of the abdomen, a serious condition called peritonitis. At that point, the infection can become life-threatening.

9. SURGEONS CAN REMOVE AN APPENDIX THROUGH A TINY INCISION.

In 1894, Charles McBurney, a surgeon at New York's Roosevelt Hospital, popularized an open-cavity, muscle-splitting technique [PDF] to remove an infected appendix, which is now called an open appendectomy. Surgeons continued to use McBurney's method until the advent of laparoscopic surgery, a less invasive method in which the doctor makes small cuts in the patient's abdomen and threads a thin tube with a camera and surgical tools into the incisions. The appendix is removed through one of those incisions, which are usually less than an inch in length.

The first laparoscopic appendectomies were performed by German physician Kurt Semm in the early 1980s. Since then, laparoscopic appendectomies have become the standard treatment for uncomplicated appendicitis. For more serious infections, open appendectomies are still performed.

10. AN APPENDIX ONCE POSTPONED A ROYAL CORONATION.

When the future King Edward VII of Great Britain came down with appendicitis (or "perityphlitis," as it was called back then) in June 1902, mortality rates for the disease were as high as 26 percent. It was about two weeks before his scheduled coronation on June 26, 1902, and Edward resisted having an appendectomy, which was then a relatively new procedure. But surgeon and appendicitis expert Frederick Treves made clear that Edward would probably die without it. Treves drained Edward's infected abscess, without removing the organ, at Buckingham Palace; Edward recovered and was crowned on August 9, 1902.

11. THE WORLD'S LONGEST APPENDIX MEASURED MORE THAN 10 INCHES.

On August 26, 2006, during an autopsy at a Zagreb, Croatia hospital, surgeons obtained a 10.24-inch appendix from 72-year-old Safranco August. The deceased currently holds the Guinness World Record for "largest appendix removed."

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