Page 65 - EVS Class 04

Different portions of the tongue are sensitive to different tastes. The taste

buds in the front, taste sweet things. Taste buds on both sides of the front
and back part of the tongue, taste salty and sour things respectively. The
taste buds at the back of the tongue, detect bitter things.

Tongue is a very delicate organ of our body and we should take good care of
it. We must clean our tongue while brushing. We should rinse our mouth

thoroughly to remove food stuck on tongue.

Teeth

Teeth help us to chew, tear, grind and eat our food. Teeth give shape to our
face and also help us to speak clearly. Crown is the visible part of a tooth.
The enamel covers the teeth. Root is the anchor of a tooth that extends into

the jawbone.
Sets of Teeth

During our lifetime we develop two sets
of teeth. A new-born baby does not have
Crown
any teeth. The first tooth appears in
about six months. A child has 20 teeth
by the time he or she is six years old. Enamel
These are called milk teeth or

temporary teeth. Temporary teeth are
lost between the age of 6-10 years.
These are then replaced by permanent
Root
teeth.

A total of 28 permanent teeth appear

upto the age of 12 years. Four more
teeth appear when a person is about 20
to 30 years old. These are called wisdom Structure of a Tooth
teeth.

There are 32 permanent teeth, sixteen in each jaw.

Kinds of Teeth

Teeth are of four different kinds – incisors, canines, premolars and molars.

Incisors are four front teeth in each jaw. They have sharp straight edges.
They are used to cut and bite food. They are also called cutting teeth.

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