| fifth cranial nerve | <anatomy, nerve> The trigeminal nerve is responsible for sensory enervation of the face and motor enervation to muscles of mastication (chewing). There are three divisions of the fifth cranial nerve, ophthalmic, maxillary and mandibular. Lesions of the sensory root to the trigeminal nerve can result in pain or loss of sensation in the face. Lesion of the motor root result in deviation of the jaw toward the paralysed side and difficulty chewing. Synonym: cranial nerve V. (27 Sep 1997) |
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| first cranial nerve | Collective term denoting the numerous olfactory filaments: slender fascicles each composed of the thin, unmyelinated axons of 8 to 12 of the bipolar olfactory receptor cells in the olfactory portion of the nasal mucosa; the olfactory filaments pass through the cribriform plate of the ethmoid bone and enter the olfactory bulb, where they terminate in synaptic contact with mitral cells, tufted cells, and granule cells. See: olfactory tract. Synonym: nervi olfactorii, fila olfactoria, first cranial nerve, nerve of smell, olfactory fila. (05 Mar 2000) |
| fourth cranial nerve | <anatomy, nerve> The trochlear nerve controls an extraocular muscle. Lesions of this nerve will result in rotation of the eyeball upward and outward (and double vision). Synonym: cranial nerve IV. (27 Sep 1997) |