Olfactory nerve (CN I)

The olfactory nerve is considered as the first cranial nerve (CN I), although it is actually a collection of the olfactory receptor cell axons and is derived from the telencephalon. The olfactory nerve is a purely sensory (afferent) nerve and transmits the sense of smell and innervates the olfactory part of the nasal mucosa located in the roof of the nasal cavity.