Olfactory Nerve(redirected from first cranial nerve)
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olfactory nerve[äl′fak·trē ‚nərv]
the first, paired cranial nerve in vertebrates. The olfactory nerve consists of the axons of the olfactory receptor cells (see). These outgrowths are among the thinnest and slowest-conducting unmyelinated nerve fibers. In mammals, in contrast with other vertebrates, the olfactory nerve does not form a single trunk, but rather, a group of separate bundles. The fibers of the olfactory nerve terminate in the olfactory bulb of the forebrain. Contact between the outgrowths of the neurons of the olfactory bulb and the fibers of the olfactory nerve occurs within the bulb, in specialized synaptic structures called olfactory glomerulae.