VTNE Review: Cranial Nerves

CN1

olfactory nerve

mediates the sense of smell

CN2

optic nerve

carries visual signals from retina to occipital lobe of the brain

causes pupil constriction

CN3

oculomotor nerve

provides motor to most of the extra-ocular muscles and for pupil constriction

observing pupillary constriction in PLR

CN4

trochlear nerve

provides motor function to the dorsal oblique extra-ocular muscle and rolls globe medially

CN5

trigeminal nerve

provides motor to muscles of mastication and sensory to eyelids, cornea, tongue, nasal mucosa and mouth

CN6

abducens nerve

provides motor function to the lateral rectus extra-ocular muscle and retractor bulbi

examined by touching the globe and observing retraction

responsible for physiologic nystagmus when turning head

CN7

facial nerve

provides motor to muscles of facial expression and sensory to medial pinna

palpebral response

observe for facial paralysis, deviation of nose to one side or droopy lips

also helps with tear production

CN8

vestibulocochlear nerve

sensory for hearing and head position

CN9

glossopharyngeal nerve

innervates the pharynx of swallowing

also innervates some salivary glands and provides taste innervation from caudal tongue

examine by eliciting a gag reflex and observing for dysphagia

CN10

vagus nerve

innervates the larynx, esophagus, and pharynx

also provides parasympathetic innervation to the heart and viscera

tested with a gag reflex

CN11

spinal accessory nerve

innervates cranial cervical muscles

CN12

hypoglossal nerve

motor to the tongue

causes tongue movement