Cranial Nerves (21%) Flashcards
CN I
olfactory
CN II
optic
CN III
oculomotor
CN IV
trochlear
CN V
trigeminal
CN V1
ophthalmic
CN V2
maxillary
CN V3
mandibular
CN VI
abducens
CN VII
facial
CN VIII
vestibular cochlear
CN IX
glossopharyngeal
CN X
vagus “wanderer”
CN XI
accessory
CN XII
hypoglossal
CN I olfactory foramen exit
cribriform plate
CN II optic foramen of exit
optic canal
CN III oculomotor foramen of exit
superior orbital fissure SOF
CN IV trochlear foramen of exit
superior orbital fissure SOF
CN V1 ophthalmic foramen of exit
superior orbital fissure SOF
CN V2 maxillary foramen of exit
foramen rotundum
CN V3 mandibular foramen of exit
foramen ovale
CN VI
superior orbital fissure SOF
CN VII facial mandibular foramen of exit
internal auditory meatus exits through styloid mastoid
CN VIII vestibular cochlear foramen of exit
internal auditory meatus
CN IX glossopharyngeal foramen of exit
jugular foramen (temporal and occipital = jugular)
CN X vagus foramen of exit
jugular foramen
CN XI accessory foramen of exit
jugular foramen
CN XII hypoglossal foramen of exit
hypoglossal canal
CN I function; nuclei and ganglia
sensory-smell; does not synapse in thalamus (olfactory neurons to mitral cells in olfactory bulb to olfactory tract to meidal and lateral stria fibers to the primary olfactory cortex (periamygdaloid area, prepiriform area and uncus BA 34) or to secondary olfactory cortex/BA28
loss of smell
anosmia
CSF leakage may indicate
skull fracture (cribriform plate damaged)
CN II optic function; nuclei and ganglia
sensory- vision; photoreceptors (rods and cones) to bipolar cells to ganglion cells to optic disc to optic n. (enter skull through optic canal) unite to form optic chiasma where medial fibers of each retina cross while lateral retinal fibers will not cross; these fibers split to form optic tracts which travel around cerebral peduncles and synapse on one of three nuclei
CN II optic nuclei (optic tracts synapse on one of three nuclei)
- lateral geniculate body relay to occipital lobe of cortex BA 17
- superior colliculus relayed to tectospinal tract (trap and SCM)
- pretectal nucleus of midbrain (light reflex)
lesion of optic nerve will result in loss of
vision of one eyeball
lesion of optic chiasma will result in
tunnel vision
lesion of optic tract will result in
loss of half of visual field
CN III oculomotor function
motor only: all extraocular eye muscles except superior oblique and lateral rectus
Superior ramus of CN III supplies (2 eye m.) Inferior ramus of CN III supplies (3 eye m.)
superior rectus, levator palpebrae superioris; medial rectus, inferior rectus, inferior oblique
accessory oculomotor nucleus of CNIII is aka
edinger westfall nucleus
edinger westfall/accessory oculomotor nucleus supplies
ciliaris and pupillary constrictor
CN IV (trochlear n.) function (SO4)
somatic motor supplying superior oblique m.
CN IV (trochlear n) nuclei and ganglia
BA 8 of cortex, superior colliculus and inferior longitudinal cplliculus sends axons to TROCHLEAR nucleus
after exiting the CNS CN IV continues within cavernous sinus, enters orbit through superior orbital fissure and supplies ___
superior oblique muscle
CN IV has communication with what plexus
cavernous plexus
CN IV is on the sup-med aspect of orbit and causes the eye to
look down/depression of eyeball
CN IV trochlear nucleus receives axons from
BA 8 of cortex, superior colliculus and inferior longitudinal colliculus
CN VI abducens n function (LR6)
somatic motor nerve supplying lateral rectus muscle
CN VI nuclei and ganglia
abducens nucleus
CN VI abducens nucleus receives axons from
BA 8 of cortex, superior colliculus and inferior longitudinal colliculus
CN VI penetrates the dura, travels along cavernous sinus and exits the skull through the SO4 and innervates the
lateral rectus muscle
eyelid droops due to weakness of levator palpebrae
ptosis
inability to constrict pupil as well as loss of light and accomodation reflexes
internal ophthalmoplegia
CN V function
sensory - face and tongue
motor - mastication “tic douloureux”
CN V nuclei and ganglia
gasserian semilunar or trigeminal ganglion “trigeminal neuralgia”
great sensory nerve of the face
trigeminal CN V
largest of the cranial nerves
trigeminal CN V
CN V nucleus of origin
trigeminal motor nucleus
one peripheral ganglion associated with CN V
trigeminal semilunar ganglion
three peripheral branches of trigeminal nerve
ophthalmic, maxillary, mandibular