Cranial Nerves Flashcards
CN I, II, III, IV
olfactory
optic
oculomotor
trochlear
CN V, VI, VII, VIII
trigeminal
abducens
facial
vestibulocochlear
CN IX, X, XI, XII
glossopharyngeal
vagus
accessory
hypoglossal
ocular group includes what nerves?
II, III, IV, VI
CN II: _
component:
function:
opening in skull:
optic nerve
sensory
vision
optic canal
3 ways to test CN II?
VA, visual fields, pupils
afferent pupil pathway?
retina - optic nerve - chiasm (hemidecussate) - optic tract - pretectal nucleus (hemidecussate) - EW nucleus
efferent pupil pathway?
EW nucleus, CN III superior divison - CG - sphincter muscle (constriction)
Relative Afferent Pupillary Defect
sign?
tested how?
results?
asymmetric pupils
swinging flashlight test
BOTH eyes dilate when light is shown to effected eye
when shown to the unaffected eye, both eyes constrict
Light-Near Dissociation
lesion where?
pupils respond to what?
pupils don’t respond to what?
dorsal midbrain/ pretectal nucleus
- response to light (fibers from pretectal to EW)
+ response to near (fibers from frontal eye fields to EW)
visual body reflex is driven by CN II,
route?
visual pathway to superior colliculus - tectobulbar/ tectospinal tracts - motor neurons in anterior gray column os SC and CN motor nuclei
CN III: _ component: functions: - - - opening in skull:
oculomotor motor innervates SR, MR, IR, IO parasympathetic pupil innervation parasympathetic accommodation stimulation levator muscle superior orbital fissure
CN III nerve nuclei? (2)
main motor nucleus
accessory parasympathetic nucleus (EW nucleus)
main motor nucleus
- groups of nerve cells that innervate _
- efferent fibers pass through _ nucleus and emerge from _ portion of midbrain
EOMs
red
anterior
main motor nucleus receives information from _ _ _
both cerebral hemispheres (including frontal eye fields)
super colliculus/pretectal nucleus
medial longitudinal folliculus
accessory parasympathetic nucleus
??????
course of oculomotor nerve?
anterior midbrain - posterior cerebral and superior cerebellar arteries - cavernous sinus - superior orbital fissure - superior and inferior rami
superior rami of CN III:
inferior rami of CN III:
levator, SR
MR, IO, parasympathetic, IR
CN IV: _
component: _
function: _
opening in skull: _
trochlear
motor
moves eye down and laterally, innervates SO
superior orbital fissure
course of trochlear nerve?
posterior midbrain - (immediately decussates) - cavernous sinus - superior orbital fissure
superior oblique actions
incyclotorsion
depression
trochlear nucleus is located _
immediate _
receives information from _ _ _
anterior to cerebral aqueduct decussation -both cerebral hemispheres -superior colliculus -MLF
_ is the longest and thinnest nerve (it emerges from back of midbrain and wraps around to move anteriorly), therefore is most at risk for trauma
trochlear
CN VI: _
component: _
function: _, innervates _
opening in skull: _
abducens
motor
abduction, ipsilateral LR
superior orbital fissure
abducens nucleus
posterior portion of _
-near _ ventricle
receives information from _ _ _ _
pons 4th -MLF -both cerebral hemispheres -superior colliculus -CN VI - abducens nerve
abducens nerve exits brainstem anteriorly via _
travels atop _
to cavernous sinus
to superior orbital fissure
pontine-medullary junction
petrous ridge
if there is damage to VI, there is often damage to _ too, because _
VII because facial nerve wraps around abducens nucleus
CN VI palsy: _
presentation?
you must _
pressure from _ lobe pressing down and squeezing VI down on _
papilledema
one eye extremely eso
DILATE
petrous ridge
medial longitudinal fasciclus (MLF)
extends from midbrain to _
links eye movement with _
spinal cord
vestibular control apparati
MLF has to do with _
parapontine reticular formation “I want to look to the right”
sensory nerves
I, V, VIII, IX
CN I: _ component: _ function: _ opening in skull: _ type of receptors: _
olfactory sensory smell cribiform plate of ethmoid bone bipolar neurons
CN V: _
component: _
three divisions: _ _ _
trigeminal
sensory and motor
ophthalmic, maxillary, mandibular
V1: component and opening:
sensory
superior orbital fissure
V2: component and opening:
sensory
foramen rotundum
V3: component and opening:
sensory and motor
foramen ovale
4 trigeminal nerve nuclei?
main sensory, spinal, mesencephalic, motor
main sensory nucleus:
- location: _
- sensations: _
posterior pons, continuous with spinal nucleus
touch and pressure
spinal nucleus:
- location: _
- sensations: _
extends length of medulla and into upper spinal cord
pain and temperature
mesencephalic nucleus:
type of nerve cells: _
sensations: _
unipolar nerve cells
proprioceptive
motor nucleus:
location: _
innervation to: _
pons, medial to main sensory nucleus
muscles of mastication/chewing
trigeminal nerve course
exits anterior pons - forward out of posterior cranial fossa - large ganglion in Meckel cave - 3 branches from anterior border ganglion
V1 - ophthalmic branch
sensory innervation to: _
cornea, forehead, scalp, eyelids, nose, mucous membranes of paranasal sinuses and sinus cavities
V1 travels through _ sinus
cavernous
3 branches of V1
NFL
nasocilliary, frontal, lacrimal
word for area innervated by certain branches of nerve
dermitomes
What is Hutchinsons’ Sign?
herpes lesions on tip of nose or along V1 pathway
-if V1 is involved, likely to see ocular involvement
V2 - maxillary branch
sensory innervation to: _
skin of face over maxilla, teeth of upper jaw, mucous membranes of nose, maxillary sinus, and palate
runs through what part of sinus?
inferno-lateral wall of cavernous sinus
emerges from foramen rotundum,
-_ ganglion
enters orbit via inferior orbital fissue, _ branch,
enters infraorbital foramen, _ branch
pterygoid palatine ganglion
zygomatic branch
infraorbital branch (terminal branch)
if orbital floor damage, check sensory, if not sensitive -order CT because likely _ nerve damage
infraorbital nerve
V3 - mandibular branch
sensory of _
motor of _
sensory: cheek skin, mandible and side of head skin, lower teeth, temperomandibular joint
motor: muscle of mastication
what is the only motor of CN V?
muscles of mastication
CN VIII: _
component: _
2 divisions and function: _ _
opening in skull: _
vestibulocochlear
sensory
cochlear -hearing, vestibular - position and movement of head, balance
internal acoustic meatus
vestibular division
information from _ and _: head position
information from _: head movement
uterine and saccule
semicircular canals
vestibular division
cell bodies in _ ganglion which lies in internal acoustic meatus
vestibular
there are 4 vestibular nuclei in the _: medial, lateral, superior, inferior
pons
a small number of fibers bypass vestibular nuclei and pass to _
cerebellum (also very involved in balance)
cochlear division
information from _ to cochlea
-how does it work?
organ of cortisones
hair cells -> mechanical sound vibrations -> nerve impulses
cell bodies lie within the cochlea and form the _ ganglion
2 cochlear nuclei in _: posterior and anterior
spiral pons (2 ears=2 ganglion)
CN IX: _
components: _
functions: _ _
opening in skull: _
glossopharyngeal motor and sensory motor - assist swallowing sensory - taste from posterior 1/3 of tongue jugular foramen
glossopharyngeal nerve nucleus
3 main nuclei: _ _ _
all housed in _
main motor, sensory, parasympathetic nucleus (inferior salivatory nucleus)
medulla oblongata
glossopharyngeal nerve course
exits anterolateral medulla as rootlets - jugular foramen - motor branch to stylophargyngeus muscle - parasympathetic fibers to parotid gland - sensory fibers to pharynx and posterior 1/3 tongue
motor neurons:
X, XII, VII, XI
CN X: _
component: _
functions: _ _ _ _
opening in skull: _
vagus
CN X: _
component: _
functions: _ _ _ _
opening in skull: _
vagus
motor and sensory
constriction of pharynx and larynx, gag reflex, help control of HR/BP, parasympathetic to lungs, heart, esopohus, stomach, SI, LI
jugular foramen
vagus nerve nuclei
housed in: _
3 nuclei: _ _ _
medulla
main motor, sensory, parasympathetic
CN VII: _
component: _
functions: _
facial
MOTOR and sensory
facial expression, stapedius muscle of inner ear, digastric and stylohyoid muscles, lacrimation and salivation, anterior 2/3 tongue
openings in skull for CN VII: _ _ _
internal acoustic meatus, facial canal, stylomastoid foramen
IFS
facial nerve nuclei:
all housed: _
3 nuclei: _ _ _
pons
main motor, sensory, parasympathetic
main motor nucleus of VII
controls muscles of face
-_ upper
-_lower
both hemispheres
contralateral hemisphere only
parasympathetic nuclei of VII
-what 2 gland nuclei? _ _
superior salivatory nucleus
lacrimal nucleus
sensory nucleus of VII
- upper par of nucleus of the _
- sensory information for _
tractus solatarius
taste
facial nerve course
motor fibers wrap around VII nucleus - motor and sensory join - leave pons laterally and and emerge from anterior surface of brainstem between pons and medulla - travels with III - enters internal auditory canal in petrous portion of temporal - through geniculate ganglion and gives 2 branches - (parasympathetic: greater petrosal nerve, sensory:chorda tympani nerve) - remaining fibers exit through stylomastoid foraemen of temporal and through parotid gland ***rewatch this, pg 12
UMN Lesion = lesion to _, which is a _
cortex, stroke
UMN affects _ which spares _ and _
contralateral lower facial weakness
eyelid closure and forehead wrinkling
UMN leaves _ _ and _ in tact
lacrimation, salivation, taste
UMN etiologies include _ _ and _
ischemia, tumor, trauma
LMN lesion = lesion to _, which is called _
CN VII, bell’s palsy
LMN causes _
ipsilateral facial hemiparesis (whole half)
LMN is considered _, but thought to be associated with virus and edema of CN VII ( _ and _)
idiopathic
inner ear infection, herpes simplex 1
with LMN there is _ involvement
no other neurological
LMN can cause incomplete eyelid closure, which results in _
exposure keratopathy
CN VII divines:
brachial motor is responsible for _
facial expressions
visceral motor is responsible for _
lacrimal and salivary gland
special sensory is responsible for _
anterior 2/3 of tongue
general sensory is responsible for _
mastoid area
CN XI: _
component: _
functions: _ _
opening in skull: _
accessory motor cranial root - muscles of soft palate spinal root - sternocleidomastoid and trapezius muscles jugular foramen
CN XII: _
component: _
function: _
opening in skull: _
hypoglossal
motor
muscles of tongue
hypoglossal canal
hypoglossal nucleus lies is _, below floor of 4th ventricle
medulla
