74 The Five Senses: Supplemental Guide 3A | I Use My Nose to Smell
Presenting the Read-Aloud 10 minutes
I Use My Nose to Smell
Show image 4A-2: Sniffing a flower
Everybody take a deep breath through your nose. This is inhaling—or
breathing in.Every time you inhale, thousands of tiny little molecules—little, tiny
pieces of things too small to see—enter your nose. These small,
invisible things are called odor molecules, and odor molecules
make up what we call scents. Scents and odors are smells. There
are millions of odor molecules floating around in the air, and they are
especially around things that have a scent like coffee, sour milk, and
flowers. Show image 4A-3: Nose diagram
When you sniff or smell a flower, odor molecules rush in through your
nostrils—the two holes at the bottom of your nose.[Point to your nostrils.]
Remember, you should never put anything in your nostrils.Once the odor molecules get into your nostrils, they travel high
up inside your nose until they reach smell receptors. Say “smell
receptors” with me.The smell receptors tell your brain what kind of scent the odor
molecules have, like the scent of a sweet-smelling flower.[Use your finger to show the path of odor molecules from outside the nose,
through the nostrils, to the smell receptors, to the brain.]
Human beings can identify—or figure out—thousands of different
kinds of scents. Show image 4A-4: Rescue dog
Dogs have an even better sense of smell than humans. Raise your
hand if you have a dog at home. Dogs have twenty-five times more
smell receptors than humans![Show this visually by drawing one smell receptor for humans on one side of the
paper or board and twenty-five smell receptors for dogs on the other side.]