How does our sense of smell work?
Food releases chemical molecules into the air and, although you cannot see them, your nose can smell them.

When these molecules reach the back of your nose, they are detected by olfactory receptors, located on the olfactory cilia of your olfactory cells.

Your olfactory nerve then transmits the information to your brain.

Perceiving odours
What is orthonasal olfaction?
When olfactory molecules reach your nose through the air you breathe in, when you sniff for example, we call this orthonasal olfaction.

Perceiving aromas
What is retronasal olfaction?
Chewing food and the heat inside your mouth releases odorous molecules, which move up towards the olfactory receptors in your olfactory mucous membrane. This is what we call retronasal olfaction, because it goes via your mouth.

How can we distinguish between ODOURS and AROMAS?
When we smell food and the odorous molecules come from the air we breathe in, we talk about smells or odours. When these molecules come from your mouth, we talk about the aroma of food.