We just learned about the Olfactory Receptor Neuron.
Another part of how noses work is the Olfactory Bulb.
This is a part of the brain right in the front that takes the messages from the Olfactory Receptor Neuron.
The neuron sends messages to the bulb, and the bulb figures out what the smells mean and sends those messages to the rest of the brain so you know what you are smelling.
(from: wikipedia - olfactory bulb)
Kid Facts - Blast from the past: Limitless Replication