Student Article
The Science of Smell: How Our Nose Understands Odors
Molecule (noun): A very small particle that makes up substances.
Receptor (noun): A structure in the body that receives sensory input like smell.
Olfactory (adjective): Related to the sense of smell.
Anosmia (noun): The condition of losing your sense of smell.
What’s that smell? The science behind your nose.
How your nose knows what you’re smelling
When you sniff the air, whether it’s the scent of pizza or a whiff of garbage, your body is doing some impressive science. Smells are caused by molecules in the air that float into your nose. There they meet special receptors at the top of your nasal cavity. These receptors send signals to a part of your brain called the olfactory bulb, located just behind the bridge of your nose. That’s how your brain recognizes and names different smells.
Your brain uses patterns to recognize scents
Humans have about 400 types of smell receptors. Each scent can trigger many of them, making a “pattern” that your brain decodes.
Why we love some smells and hate others
So why does fresh popcorn smell great, but rotten eggs make us gag? That’s a tricky question. Smells can protect us by warning us of danger, like spoiled food or smoke. But scientists like Dr. Andreas Keller say that our reactions are also shaped by DNA and experience. For example, butyric acid is found in both Parmesan cheese and vomit — your brain might react differently depending on the situation!
Some people can’t smell certain things
Some people can’t smell certain things at all. This is called a “blind spot.” A common example is not noticing the smell in your pee after eating asparagus. Some people lose their entire sense of smell — called anosmia — after a cold, infection, or injury. It doesn’t just affect how food tastes — it can make life feel dull. The good news? Smell training with strong scents like essential oils may help bring it back.
© Anand Jagatia / Our Media
Molecule (noun): A very small particle that makes up substances.
Receptor (noun): A structure in the body that receives sensory input like smell.
Olfactory (adjective): Related to the sense of smell.
Anosmia (noun): The condition of losing your sense of smell.