Cranial Nerves: OLFACTORY (1) NERVE. - this nerve is entirely sensory, it contains axons that conduct nerve impulses for olfaction, the sense of smell. - bundles of axons of olfactory receptors extend through foramina in the cribiform plate of the ethmoid bone.ROCHLEAR (4) NERVE. - is a motor cranial nerve. It is the smallest of the 12 cranial nerves and is the only one that arises from the posterior aspect of the brain stem. - the somatic motor fibers innervate the superior oblique muscle of the eyeball.