Fun fact 10 of 10
10. The tongue map we learned in school is a myth
That drawing of the tongue divided into areas, with sweet on the tip and bitter at the back, is wrong. All regions of the tongue with papillae can perceive all the basic tastes.
A misreading that became a lesson
The idea came from a German study from 1901, which measured small differences in sensitivity in parts of the tongue. Decades later, an American book reinterpreted the data in an exaggerated way, and the subtle differences became separate zones, each with one taste.
In reality, taste buds are spread across the tongue, the roof of the mouth and the throat, and each one has cells capable of perceiving the basic tastes. Some areas may be slightly more sensitive to one taste, but the difference is small.
Today five basic tastes are recognized: sweet, salty, sour, bitter and umami, the taste associated with broths, aged cheeses and ripe tomatoes. Umami was proposed in 1908 by the Japanese chemist Kikunae Ikeda, but it was only widely accepted much later.
Much of what we call flavor actually comes from smell. The aromas of food rise through the back of the nose while we chew, which is why everything seems tasteless when we have a cold.
Did you know? Taste buds renew themselves frequently: the cells that form them last on average from 10 days to two weeks and are then replaced.
The 10 fun facts in this list
- You become about 1 centimeter shorter over the course of the day
- A baby is born with more bones than an adult
- The smallest bone in the body is inside the ear
- Identical twins do not have the same fingerprints
- The brain does not feel pain
- The stomach replaces its own lining every few days
- The cornea receives oxygen directly from the air
- Fingernails grow faster than toenails
- Yawning is contagious, and it begins before birth
- The tongue map we learned in school is a myth
Where this information comes from: NASA (astronaut height); Federal University of Rio de Janeiro, 2009 (neurons); Nobel Foundation, 2005 (Helicobacter pylori); Journal of the American Academy of Dermatology, 2010 (nail growth); studies by Andrew Gallup on yawning; anatomy and physiology textbooks for the other items.
