What are the mechanics of smell?


I tagged this as other because idk what branch of study this question would belong to.

But my question is. If I am I’m a room with a flower, I can smell the flower, how? Is the flower emitting gas? Some older posts that asked similar questions had comments saying something about volatile chemicals and particles but then didn’t explain what that meant or how particles still give off a smell.

So, what’s happening? I know our nose is essentially a chemical detector that sends signals to the brain. But what is it detecting and how does whatever it is get there in the first place?

The simplest way I can phrase this question, using the above example, would be: how does the smell from the flower get to me and what is it that actually gets to me?

If this doesn’t get auto-modded then thanks in advance

In: 2

So, chemicals react in various ways; and when they do, they do various things. Our body creates chemicals (called “proteins”) that react when then encounter particular pieces of chemicals, and trigger responses in our nervous system – and puts most of them in cells in our nose. Our brain then puts together those responses to determine “smell”.

However, the details of this is still something scientists are working out. What we know is that chemicals from the world come into our nose, react with proteins, which signal our nerves. We don’t know the details of how the “react with proteins” works. We do know it’s not one to one: humans have only about 1300 genes for smell detecting proteins – but can smell about 10 000 different smells. However, we’re still trying to figure out the mechanics of how those proteins work.

I’m going to link the most recent paper that I could find that does a decent job of explaining what we do know. It’s probably at the high school or early college level; but it might help: