Which cranial nerve is associated with the sense of smell?

The olfactory nerve is specifically responsible for the sense of smell. It is classified as cranial nerve I and has sensory functions that allow it to transmit odor information from the nasal epithelium to the brain. This nerve consists of sensory nerve fibers that penetrate the cribriform plate of the ethmoid bone and form synapses in the olfactory bulb, from where the olfactory tract carries signals to the olfactory cortex.

In contrast, other cranial nerves have different functions. The optic nerve, for example, is involved in vision, transmitting visual information from the retina. The trigeminal nerve is primarily responsible for sensation in the face and motor functions such as biting and chewing. The facial nerve controls the muscles of facial expression and carries taste sensations from the anterior two-thirds of the tongue. Understanding the specific functions associated with each cranial nerve helps clarify why the olfactory nerve is the correct choice for the sense of smell.