How does the nose smell?

Your nose is two 10 cm tunnels with a stamp-sized smell patch in the roof, about 400 kinds of receptor, and a direct line to the brain's memory centres. Sniff air up to the patch, watch molecules fit their receptors, and see why a mango is mostly smell.

Read how it works: How does the nose smell? · The history of understanding smell · More boxes on Glassbox

Chapters in this interactive model

1. Inside your nose: Two tunnels, three curly shelves, and a stamp-sized smell patch in the roof.
2. Your nose, the air conditioner: Warm, wet and clean: what happens to air in the tenth of a second it spends in your nose.
3. Locks, keys and barcodes: About 400 kinds of receptor, and every smell lights up its own combination.
4. From nose to brain: Why a smell can bring back a memory before you even know what it is.
5. Flavour is mostly smell: Your tongue tastes five things. The rest of a mango comes up the back of your nose.
6. When smell goes wrong: Colds, COVID-19, getting older, and the smell that is added to gas to keep you safe.