Page 23 - EVS Class 05

While Breathing In While Breathing Out

The ribcage moves outward and The ribcage moves inward and
upward with the help of the downward with the help of the
muscles of the chest. muscles of the chest.

The diaphragm contracts and The diaphragm relaxes and rises up.
flattens out.

The chest expands. The chest contracts.

Air goes into the lungs. Air goes out of the lungs.

Helping Fire to Burn by Blowing

In olden days, people used a chulha for

cooking. They lit firewood in the chulha. They
used to blow air through a pipe to keep the
fire burning. Through our breath, we increase

the supply of oxygen. That is why the fire
burns more brightly.

Cooling by Blowing

The water vapour in the air we breathe out makes the heat
coming out of the hot milk or soup escape faster. So,
blowing air from mouth cools the hot drinks.

Always Breathe Through Nose

Our nose has some tiny and fine hair. These hair
trap the dust and germs present in the air we
breathe and prevent them from entering our

lungs. But, when we breathe in air through the
mouth, the air that enters our lungs is not clean.
It carries dust and germs into our lungs through
air and we may fall sick.

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