Final answer:
Smell receptors transmit signals to the brain via the olfactory nerve. The olfactory nerve carries information from the olfactory neurons to the brain, where it is processed in areas related to smell, memory, and emotion.
Step-by-step explanation:
Smell receptors send messages to the brain via the olfactory nerve. This nerve is the first cranial nerve and is exclusively responsible for the sense of smell. The process of olfaction begins when olfactory neurons in the nasal cavity detect odorant molecules. These neurons have axons that project through the cribriform plate and terminate in the olfactory bulb. The olfactory bulb contains structures called glomeruli, where these signals are sorted according to the specific odorant and then relayed to the brain. From the olfactory bulb, signals are sent to various brain regions including the olfactory cortex, the frontal cortex, and the limbic system - all of which are involved in processing smell, linking it to memories, and eliciting emotional responses.