Definition of Cranial nerve I

Cranial nerve I: The first nerve to emerge from or enter the skull (the cranium). (There are twelve cranial nerves.) The first cranial nerve is the olfactory nerve which permits the sense of smell. See: Olfactory nerve.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=7560
Last Editorial Review: 10/9/2012