The actual organ of taste is called the "taste bud."
There are approximately 10,000 taste buds in a human tongue when you are born..
Animals can even have more.
As a person ages, some of his or her taste buds die.
An old person may only have 5,000 taste buds left.
That's why some foods may taste stronger to you than they do to an adult.
Taste buds can detect sweet, sour, bitter, and salty flavors.
Molecules of food stimulate the taste cells to send messages to your brain. The sweet and salty buds are the least sensitive and the bitter ones are the most sensitive.
Each taste bud is made up of many (between 50-150) receptor cells.
Receptor cells live for only 1 to 2 weeks and then are replaced by new receptor cells.
Sometimes you burn your tongue, by hot food, or by spicy food, and a lot of tasty buds get damaged.
Luckily your tongue replaces these damaged tasty buds.
Each receptor in a taste bud responds best to one of the basic tastes.
A receptor can respond to the other tastes, but it responds strongest to a particular taste.
The top of your tongue is covered with a layer of bumps called papillae.
Notice how it's rough and bumpy - not like the underside, which is very smooth.
Papillae help grip food and move it around while you chew. And they contain the taste buds.