Cranial Nerves Flashcards
CN I
longest or shortest CN?
function
modality
shortest CN
olfactory nerve
function: smell; detects food through odiferous molecules
SVS (special visceral sensory)
damage to CN I causes
anosmia (inability to smell)
parosmia (distortion to smell or taste)
CN II
modality
part of what system
function
optic nerve
SSS: special somatic sensory
part of visual sensory system
transmits signals generated by photoreceptors of retina
what are 2 reflexes of CN II?
light reflex (constricts pupils)
accommodation reflex (adjusts thickness of lens for NEAR focusing)
CN III
modality and function
modulates what reflex
oculomotor nerve
GSM general somatic motor (skeletal muscles) - moves extrinsic eye muscles
GVM general viseral motor (smooth muscles) - pupil sphincter and cilliary muscle
modulates accomodation reflex
damage to CN III results in]
how to exam damage
damage to globe causing double vision or ptosis
tested by having eye follow moving object
ptosis
eye rotated down and out with a fixed, dilated pupil
CN IV
modality
smallest/biggest and longest/shortest nerve?
function
trochlear nerve
GSM- general somatic motor
smallest & longest oculomotor nerve
function: superior oblique (moves eye down & medially)
damage to CN IV results in
diplopia - double vision
CN V
function
smallest/largest nerve?
modality
divisions (3)
function: sensation to scalp, forehead, nose, sinus, & muscles of mastication
largest nerve
3 divisions: opthalmic, maxillary, mandibular
GSS- general somatic sensory
CN VI
function (mention specific muscle_
originates from what brain structure
modality
abducens nerve
function: ctrls lateral rectus muscle (outward movement of eye)
originates from pons
GSM - general somatic motor
damage to CN VI
inward deviation (adduction) of eye
CN VII
modalities & functions (4)
facial nerve
1. General somatic sensory: sens. to ext. ear
2. Special visceral sensory: taste
3. Special visceral motor: muscles of facial expr.
4. General visceral motor: glands
damage to CN VII results in
tested by
bells palsy - idiopathic (usually) temporary facial paralysis
tested by: asking pt to make expression and test for symmetry
CN VIII
modality
function
vestibulocochlear nerve
SSS- special somatic sensation
funct : hearing & balance
damage to CN VIII results in
pathologies of CN VIII
damage to cochlear nerve = partial/complete deafness
pathologies: vertigo, loss of equilib., nystagmus
nystagmus
rapid, involuntary eye movement
CN IX
innervates ______
modalities and brief description
glossopharyngeal nerve
innervates stylopharyngeous of pharynx
GSS- posterior pt of tongue & ear
GVS- carotid body & sinus
SVS- taste from posterior pt of tongue
GVM- parotid gland
SVM- stylopharyngeus
damage to CN IX results in
abscence of gag reflex
reduced taste to bitter/sour
difficulty swallowing
CN X
innervates ____
longest/shortest cranial nerve
component of which pt of nervous system
innervates muscles of phonation
longest cranial nerve
main component of PNS
modalities of CN X
GSS- ext. ear, larynx, pharynx
GVS- sensation of organs in abd/thoracic cavities
SVS- taste signals
GVM- cardiac muscle & parastalsis
SVM- pharynx/larynx (phonation and swallowing
which cranial nerve is responsible for reducing resting heart rate?
what medication can reduce heart rate?
CN X - vagus nerve
beta blockers
CN XI
modalities and function
what are its 2 roots?
accessory nerve
GSM- trapezius (shrug shoulders) & sternocleidomastoid (turn head)
2 roots: cranial and spinal
CN XII
modality
ex of voluntary and involuntary function
clinical examanition
hypoglossal nerve
GSM- voluntary and involuntary muscles of tongue
voluntary (speech, eating) & invol (clearing saliva)
clin exam: ask pt to put tongue against cheek
