The Nose and How We Smell

By Diandra, Patirica, Jennie and Julian



In order to smell, we first have to inhale molecules. These molecules can come from anything, but are usually from objects that have a high molecular volatility – that is they shed their outer molecules into the air inside of being bound. Inside your nose a patch of neurons that are exposed to air inside the nasal cavity, unlike other neuron endings in your body. They have small cilia covering them, which then capture the drifting molecules that you inhale and cause the smell sensation.

Each receptor and cilia is designed to react to a specific molecular and chemical composition. There are several conflicting theories about how exactly the olfactory (smell) sense works. Some posit that neurons and receptors are keyed to acknowledge a specific feature in the chemical compound they absorb, however Vibration theory operates under the assumption that the receptors can actually tell the oscillation of the electrons inside the molecular structure.

Humans tend to have a relatively weak sense of smell compared to similarly sized mammals, and have the least sensitive sense of smell out of all primates.

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