The Fragrance Foundation UK

Our sense of smell is directly connected to the limbic system, the most ancient and primitive part of the brain, which is thought to be the seat of emotion. Smell sensations are relayed to the cortex, where ‘cognitive’ recognition occurs, only after the deepest parts of our brains have been stimulated. By the time we correctly name a particular scent, the scent has already activated the limbic system, triggering more deep-seated emotional responses.

The sense of smell allows us to detect information from our environment and all that inhabits it. It is the oldest of all the senses and relies on odorants in the form of volatile molecules to stimulate it.

So… how does it work?!

As an odour molecule enters our nose it travels towards the mucous membrane, which is located at the top of the airway either side of the nasal septum, where the scent receptors are located.

The odour molecule swirls over the mucous membrane until it finds an olfactory receptor that it fits into, which then sends a message to the brain.

This phenomenon is often referred to as the lock and key theory – the receptor works like a lock, the odour like a key.