The longest human tongue on record stretches 3.86 inches from lip to tip. That may not seem like much compared with the tongue of the giant anteater (two feet long) or of the Morgan’s Madagascan sphinx moth (a disturbing seven times as long as its entire body). But stubby though it may be, the human tongue is a remarkably versatile organ. It can contort into nearly limitless shapes, allowing us to chew, swallow, and carry on a good conversation. When we eat, it translates the chemistry of our food into electrical impulses for our brain. In a pinch, it can even assist with vision and mobility: engineers are refining tongue-controlled systems to help blind people see and allow paralyzed people to operate a wheelchair. Through wide-ranging research, scientists are gaining a newfound appreciation for the marvels of this multitasking organ.
ROUGHING IT The surface of the tongue is studded with hundreds of small bumps called papillae. Some (center) house several taste buds, while others (in red) lack buds. Supertasters, who experience flavors more intensely than average, seem to have an overabundance of papillae. On the flip side, bad behavior can dull your experience. A 2009 study of Greek men found that smokers displayed flatter papillae with a reduced blood supply and experienced a diminished sense of taste.
TONGUE TWISTER The tongue’s 16 muscles gather food and push it down the esophagus. They also produce an array of consonants by partially obstructing airflow within the mouth. Cornell University scientists recently used high-speed ultrasound to image the tongue movements used in an African “click” language. For the first time, the researchers were able to understand the rapid motions of the back of the tongue that produce unusual inhaled consonants.
A MATTER OF TASTE Taste buds consist of a group of sensory cells that absorb food molecules and transmit the sensation of sweet, sour, salty, savory, or bitter flavors to the brain. Every bud is sensitive to multiple flavors, which are encoded by different nerve-firing patterns. Your feelings about brussels sprouts could come down to a single gene: Researchers at the University of Connecticut found that people missing the receptor for a bitter chemical called PROP tend to like veggies rich in the compound.
DROOL-WORTHY Salivary glands under and on the tongue pump out a quart of liquid each day. By dissolving chemicals from food, saliva allows us to taste. The fluid could even help diagnose disease. Researchers have found differences between the saliva protein profiles of healthy individuals and those with certain cancers. And there is value to licking your wounds: Dutch scientists identified two compounds in human saliva that help wounds heal faster.