Wade Moore, age 8, of Florence, South Carolina, for his question:
How do the taste buds taste?
They do it with chemicals, moisture and a sort of telephone system that flashes news items to the brain. Your choosy little taste buds are buried in the skin of your tongue and several other damp places inside your mouth. They also share information with sensitive smelling cells in back of your nose and throat. You have hundreds of little taste buds and each one is a hump made from many tiny taster cells.
The body has millions of sensitive cells and all of them work in much the same way. When they sense bits of information, they flash these reports to the brain. Your fingers know the difference when you touch a hot stove or a chunk of ice, a smooth glass or the furry coat of a cat. Clever cells of this sort are buried in the skin all over your body. They are connected to finer than fine nerve threads that lead to the brain. And the brain lets you know whether you are touching something hot or cold, smooth or rough.
The taste buds, of course, are very special sensing cells that report the flavors of your food. They too are connected to nerves that carry their reports to the brain. As the nerves pass through the body, the fine ones merge together to make larger ones. Those from the taste buds meet with the lower back part of the brain. There the strands that carry messages about different flavors separate and travel onward to the clever region in front of the brain. So far, the messages are in code. But when they reach the brainy part of the brain they are translated into the taste signals that we can understand
Strange to say, tastes and flavors come from certain chemicals in our foods. The taste buds use their own sensitive chemicals to tell which flavor is which. But to do this, the little bumps must be moist and fairly warm. This is because the chemicals they use must be dissolved in liquid. Of course, the liquid they use is the moist saliva that oozes all over the skin inside the mouth.
Some taste buds can sense the difference between all sorts of different flavors. But others are specialists. There is a group of tasters near the tip of your tongue. It knows when you lick a lump of sugar or something sweet. Along side of your tongue you have a group of tasters who send messages when you eat salty food. Two other groups, farther back along the sides of your tongue, report sour flavors. Another group on the back of the tongue can taste bitter flavors.
Most foods are blends of different flavors and the taste buds work together to test them. They work very hard, testing all the chemicals that get dissolved in the moisture inside your mouth. In fact, the busy taste buds soon wear out their sensitive cells. But as old ones become useless, new ones are formed. Every ten days or so, about half the weary old taster cells are replaced with keen new ones.