What Causes the Smell of Things?

[i.mehrzad]

Smelly stuff?

Well what is the cause that something smells. That is what does a substance emit before entering the nasal chamber of our nose that enables us to smell things?? Or does it really emit anything?

 

[Moonbear]

Yes, for us to smell something, small particles must become airborne. There are then receptors in the nose that these particles interact with (different types of receptors can interact with different types of airborne chemicals). The information from the numbers and types of receptors that are "triggered" when these chemicals bind to them is then sent to the brain where it is processed and interpreted.

You may or may not know that just a few years ago, two scientists, Axel and Buck, won the Nobel Prize in Physiology and Medicine for their work on the olfactory system. There is a very nice explanation of how the system works, written as a press release for a general audience, on the Nobel website.

http://nobelprize.org/nobel_prizes/medicine/laureates/2004/press.html

I'm certainly not going to attempt to explain it any better than Nobel prize winners who have studied that system.