Renita Bailey, age 11, of Lansing, Mich., for her question:
HOW DOES THE TONGUE WORK?
An animal with a most unusual tongue is the lizard found in Madagascar and Africa called the chameleon. The lizard has a thin, sticky tongue that is almost as long as its six inch long body. Controlled by powerful muscles in the throat, the tongue is almost as fast as a streak of lightning. At the end of the tongue is a sticky, knoblike tip that swells out.
In man, the tongue is the chief organ of taste and it is also used to help him chew and swallow his food. In addition, the tongue plays a vital part in allowing man to form the sounds of words.
Many groups of muscles that a person can consciously control make up the tongue. This type of muscle is called skeletal muscle. The tongue muscles run in a number of different directions. They come up from the hyoid bone and the inner surfaces of the lower jaw and also from the temporal bones.
Because of the strong muscle network, a person can move the front part of the tongue many different ways. The tongue can move food around in the mouth, push it between the teeth, roll it into small masses and thrust it back into the throat.
In swallowing, the tongue presses against the roof of the mouth, which is called the palate, and also spreads against the sides of the mouth. This action prevents the food from moving in any direction except back into the throat, which is called the pharynx.
A mucous membrane covers the human tongue. The under surface is smooth while the rough top is covered by many small projections called papillae.
Four different types of taste buds are found in the tongue's papillae that allow us to tell the difference between sweet, sour, salty and bitter tastes.
The tip of the human tongue is more sensitive to the feeling of touch than any other part of the body.
Dogs, cats and other animals use their tongues for a lot of different purposes, including lapping up water or milk, cleaning their fur and expressing affection.
The tongue is also an extremely useful organ to other animals. A hummingbird, for example, can use an extremely long tongue to lap up plant nectar. Moths and butterflies also use long, slender tongues as a way of getting food.
Frogs and toads have tongues that are attached at the front of the mouth. The tongue has a sticky surface. The animal flips its tongue at its prey in a quick, rolling motion. It catches the prey on the sticky surface and draws it into its mouth. It moves so fast it cannot easily be seen.