Untitled Document
 Your
tongue helps you speak. It also helps you swallow and chew your food. Imagine that
you are eating an apple. How would you be able to move the pieces
of the apple around in your mouth if it wasn’t for your tongue? How
would you be able to push the food under your teeth to chew and then
move the food back to swallow? Your tongue is a very important part
of your mouth. It is also very important in the mouths of other mammals
and fish.
Researchers at Brown University in the U.S. have recently discovered that the tongues
of fish and mammals work in different ways. The tongues of fish (such
as the bowfin or pike) use their muscles to pull the food
deeper into their mouths for processing and then digestion. Chewing in fish
begins with the tongue positioned at the upper part of the mouth.
The fish then uses a muscle called “sternohyoid” to push the tongue
down, then retract it inwards before moving it
out and up again, to its original top position.
So, if we were to look at the fish’s mouth from the side, we would
see the tongue moving in a clockwise direction, drawing the food farther back. The tongues
in fish basically serve to transport food quickly through
their mouths, where most fish species have an extra set
(or sets) of jaws to grind the food before it
is swallowed. Another cool thing their tongue does is to push oxygen-rich water through
the mouth to their gills so that they can breathe.
Now, what about mammals? Well, mammals like goats and pigs use their
tongues quite differently. Instead of pulling the food to process
it, it uses its tongue muscles to move food to the ideal spots where their teeth
can break it down most effectively. So the animals’
tongues thrust out, then up as they
began to chew, and then back to its original bottom place. When looking
at their mouths from the side, researchers saw that their tongue moved
in a counter-clockwise direction.
Try to concentrate on what your
tongue is doing the next time you are chewing food.
You will notice that it moves out from its regular spot, then up in
order to push the food around, and then back as you chew. Another
awesome thing the researchers
found was that lizards use their tongues
in the same way that mammals do! This study can give better insight into how the method
of using the tongue changed with evolution, as some amphibians became terrestrial over time. |
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