How We Smell
How does our sense of smell work?
Most of us don’t give much thought to how our sense of smell works. We simply inhale, take a deep breath and instantly smell odours and aromas around us. It is one of our most reliable senses with only 1% of North Americans ever reporting problems with their sense of smell. Our sense of smell is a complex chemosensory system, closely connected to brain, that serves a multiple purposes. One of these is our ability to enjoy and distinguish fragrances and perfumes.
Now, here is a very basic science class in how our sense of smell works:
Odor molecules travel through your nasal passages to two tiny patches of tissue located behind the bridge of your nose. These patches are comprised of millions of special smelling sensors that connect directly to the brain. Each olfactory detecting neuron has one odor receptor. When you inhale and draw in microscopic odor molecules like your favourite fragrance, these stimulate the receptors. What’s interesting is the odor molecules dissolve in moisture and bind to tiny nerve hairs on the cells. Once the neurons detect the molecules, they send messages to your brain, which quickly identifies the smell. Any given molecule may stimulate a combination of receptors, creating a unique representation in the brain. It is the limbic system, our emotional centre, that is largely devoted to smell. So you can see why scent is so closely related to emotion.
How taste and smell are connected:
Have you ever noticed how closely linked your sense of smell and taste are? That isn’t by accident. There are actually two pathways for smells to reach your olfactory sensory neurons. The first is through your nostrils as described above. The second is a pathway that connects the roof of your mouth to your nose. You may have noticed in the past that chewing food releases aromas that reach your sensory neurons. If you lose your sense of smell, you lose much of your ability to distinguish a food’s flavour.
Here’s where our sense of experience perfume that gets particularly interesting. When we inhale, odour molecules enter our nasal passage where tips of olfactory cells with hair-like structures wait for them. A perfume contains a bouquet of different smells, each one being a distinct smell. Most modern eau de parfums contain bergamot, lemon, rose, vanilla and woods. Each one of these is a separate smell. Consequently, a scent stimulates a unique combination of olfactory cells, creating a distinct activity pattern that is transmitted to the brain. It’s a complex and highly reliable system.
So, let’s give our sense of smell a big round of applause. It’s one of the least understood and appreciated of our senses. With such a complex system in place it is a true wonder that it performs such a reliable service to us. It truly enriches our lives in so many ways – not the least in the world of fine fragrance.