The path of air

The idea

Air enters through the nostrils into the nasal passages, where hair and mucus trap dust, then through the windpipe, whose two branches enter the lungs and divide into finer branches ending in balloon-like sacs called alveoli.

A breath's journey

Air goes in through your nose.

What do the tiny hair inside your nostrils do?

• They help trap dust and dirt
• They smell the food
• They warm the food

Follow the air

Press Next part again and again until the air reaches the alveoli.

Six parts in a row

The air passed the nostrils, the nasal passages, the windpipe, the two branches, the finer branches and the alveoli. In the nose, hair and mucus trapped dust.

Air enters through the nostrils into the nasal passages, where hair and mucus trap dust. It then goes through the windpipe, whose two branches enter the lungs and divide into finer branches ending in balloon-like sacs called alveoli.

Notes

Air enters through the nostrils into the nasal passages, where hair and mucus trap dust. It then goes through the windpipe, whose two branches enter the lungs and divide into finer branches ending in balloon-like sacs called alveoli.

Check yourself

What traps dust and dirt in the nasal passages?

Why should we breathe through the nose and not through the mouth?

How many branches does the windpipe form to enter the lungs?

The finest branches in the lungs end in balloon-like sacs called …

• Teeth and saliva. Teeth and saliva are in the mouth. Hair and mucus in the nose trap the dust.
• Hair and mucus — correct. Yes!
• Ribs and diaphragm. The ribs and the diaphragm help in breathing. Hair and mucus in the nose trap the dust.
• The mouth cannot take in air at all. Air can enter through the mouth, but hair and mucus in the nose trap dust and dirt.
• The nose makes the air hot. The nose traps dust and dirt. That is the reason given in the book.
• The nose traps dust and dirt from the air — correct. Yes!
• Two — correct. Yes!
• One. The windpipe forms two branches, one for each lung.
• Ten. The windpipe forms two branches, one for each lung.
• nostrils. The nostrils are the openings of the nose.
• alveoli — correct. Yes!
• ribs. Ribs are bones that protect the lungs.