Test 1: Cranial Nerves Flashcards
CN I name, function, test
olfactory
smell
have pt identify familiar smells
CN II name, function, test
optic
vision
read close and distant items
CN III name, function, test
oculomotor
eye movement/pupil reflex
eye tracking in all directions, pupillary response to light
- damaged = eye slightly depressed and rotated toward nose
CN IV name, function, test
trochlear
superior oblique eye muscle innervation
observe eye position at rest; elevated if there is a problem
CN V name, function, test
trigeminal
muscles of mastication and face sensation
observe jaw motion, can palpate temporalis
CN VI name, function, test
abducens
lateral rectus of eye innervation
look at eye movement,
** damaged = cant look outward
CN VII name, function, test
facial
muscles of facial expression, taste to anterior 2/3 of tongue
look for facial asymmetries, observe motions; taste with common liquids
CN VIII name, function, test
vestibulocochlear
hearing and vestibular
rub test next to ear; tuning fork; observe balance
CN IX name, function, test
glossopharyngeal
sensation and tasts to posterior tongue and pharynx
ask about swallowing, gag reflex
CN X name, function, test
vagus
innervates epiglottis and larynx, parasympathetic innervation of internal organs
voice hoarsness with increased HR and RR are signs
CN XI name, function, test
acessory n
trapezius and SCM innervation
observe quality of shoulder shrug and turn head both ways
CN XII name, function, and test
hypoglossal
tongue muscles
observe tongue protrusion and mobility
** lateral movement indicates unilateral lesion
pneumonic for sensory, motor, or both function of cranial nerves
Some
Say
Marry
Money
But
My
Brother
Says
Big
Brains
Matter
More
what SPECIAL senses do cranial nerves control
taste
vision
hearing
smell
balance
CNs are most likely injured how
fx to base of cranium
head trauma/excessive brain movement
compression from tumor, aneurysm, or inflammation
how does scent travel through the olfactory n
nasal chemoreceptors to the olfactory bulb
How does vision travel via the optic n
from retina to thalamus to other projections to the visual cortex
describe the 2 tests for optic n
visual acuity = snellen chart; quadrant test of each eye
pupillary light reflex = shine light in one eye and see of both eyes constrict
specific function of occulomotor n
medial inferior, superior rectuc, and levator palpebrae muscles innervation
constriction of pupil
tests for occulomotor n (CN III)
visual oculomotor = H test; smooth pursuits; convergence/divergence
pupillary light reflex testing
observe for ptosis (droopy eyelid)
specific function of CN IV trochlear
medial/downward eye movement
innervates superior oblique m
test for CN IV trochlear n
visual oculomotor test (H test)
smooth pursuit inferiorly
specific function of CN V trigeminal
sensory for face, eye, anterior ear
touch sensation only of anterior 2/3 of tongue
muscles for mastication
what are the 3 branches of the trigeminal n
1 = opthalamic
2= maxillary
3= mandibular
tests for the trigeminal n
sensory testing of face; pinprick and light touch
resisted opening of jaw/palpation of mastication muscles
corneal blink reflex (touch cornea)
jaw jerk reflex; strike finger on pt jaw and observe for movement; no movement is normal
specific function of CN VI abducens
innervates lateral rectus
lateral eye movement
tests for CN VI abducens
visual oculomotor test (H test)
smooth pursuit laterally
specific function of CN VII facial
motor for facial n
sensory for special sensory taste of anterior 2/3 of tongue
ANS: tearing/salvation
tests for CN VII facial; injury to this n is called what?
muscles of face- look for symmetry: smile, show teeth, puff cheeks, raise eyebrows, frown
taste foods on tip of tongue; sweet, sour, salty, and bitter
**injury to this n is called bells palsy
specific function of CN VIII vestibulocochlear
vestibular branch = head position
cochlear = sound
special sense of hearing and equilibrium
tests for CN VIII vestibulocochlear n
cochlear branch:
-fingertip rub by ear
-weber test - tuning fork on top of head
-rinne test - tuning fork on mastoid process
vestibular branch
-VOR testing - i.e. head thrust
-caloric testing
CN IX glossopharyngeal specific function
touch sensation to posterior 2/3 of tongue
special sensory taste to posterior 2/3
innervates pharyngeal muscle and parotid salivary gland
tests for CN IX glossopharyngeal
gag reflex
-afferent signal
-touch pharynx
taste of posterior tongue
function of CN X vagus
throat and visceral muscles and sensory nerves
larynx, pharynx, and viscera
ANS control of throat, lungs, heart, GI, pancreas, gall bladder
important for flight or fight
tests for CN X vagus
phonation
-have pt say ah
-check for deviation of uvula
gag/swallow
-efferent/motor response of muscles
-observe swallow on command
CN XI specific function
innervates trapezius and SCM
test for CN XI accesssory
muscle resistance
check for asymmetry
-resisted shoulder shrug
-resisted head RT
specific function of CN XII
innervates muscles of tongue
ipsilateral muscles
tests for CN XII hypoglossal
stick tongue out; look for deviation (weakness is on side it deviates to)
LMN injury; being pushed to ipsilateral weaker side by contralateral/stronger side
UMN injury; stroke will deviate to OPPOSITE side (i.e. R side CVA = L side deviation)
explain this difference between UMN and LMN injury that results in a R side facial droop
Injury to the L CNS could cause a R side facial droop; pt would still have some input just not a full smile
injury to CN VII in the PNS would also lead to a R side facial droop; pt would not be able to move R side at all. No input present for facial muscles
when is CN VII vulnerable to compression
when a viral infection produces inflammation and swelling of the n just before emerging from the stylomastoid foramen
what should be the response to the pupillary light reflex in a healthy person
if you shine a light in one eye, both eyes constrict
steps involved in the pupillary light reflex
Light picked up by CN II (ipsilateral side)
goes to brain for processing
goes to CN III on both sides
CN III causes pupils to constrict
