Smell Cells

Lesson 1

Nerve cells in your nose

Smell cells are a special kind of nerve cell. They live in a small patch at the very top of the inside of your nose.

Each smell cell has tiny hairs that poke into a thin layer of mucus. At the other end, a long wire goes up through a thin bone to your brain.

Wow!

You have millions of smell cells. They come in about 400 different kinds!

Lesson 2

1. Things like cookies and flowers give off tiny bits called smell molecules.
2. When you breathe in, they float up your nose and land in the mucus.
3. If a smell molecule fits a smell cell's receptor, the cell sends a signal to your brain.
4. Your brain reads which cells are signaling, and you know the smell.

Try this

Scroll up to the 3D model and press Sniff!, then Send to brain.

Lesson 3

Smell messages go to parts of your brain that handle memories and feelings. That's why a smell can suddenly remind you of a place or a person.

Try this

With a grown-up, close your eyes and sniff a few kitchen things, like an orange, cinnamon, or a coffee bean. Can you name each one by smell alone?

Wow!

Most nerve cells are never replaced. Smell cells are different! Your body makes new ones about every month or two.

Quiz