Cranial nerve
Smell molecules called aromatics come up the nose and into the nasal cavity. Here, they are detected by olfactory neurons. These neurons are branched out along the lining of the nasal cavity. Olfactory neurons take in the signal from the smell molecules and make electric signals called action potentials. The action potentials move up the olfactory neurons through the roof of the nasal cavity, also known as the cribiform plate. After passing through the cribiform plate, the olfactory neurons send the action potentials to the olfactory bulb. From here, signals are sent through the olfactory tract and out to different parts of the brain. For example, some signals are sent to the frontal lobe, where smells are identified and labeled.