CNS Cranial Nerves Witwer Slides 1-65 Flashcards
Label the CNs in this image
The brainstem consists of what three structures?
midbrain, pons, and medulla
The bulb of the corticobulbar tract contains which two structures?
Pons and medulla
The corticobulbar tract is a _____ tract that connects the motor nuclei of the _____, _____, _____ via the _____ of the internal _____.
motor
head, face and neck
genu
capsule
Choose the best answer:
The corticobulbar tracts innervate:
a) Ipsilateral and contralateral cervical nuclei
b) Ipsilateral and contralateral cranial nerve nuclei except for ipsilateral only innervation of CN VII and XII
c) Ipsilateral and contralateral cranial nerve nuclei except for contralateral only innervation of CN VII and XII
c) Ipsilateral and contralateral cranial nerve nuclei except for contralateral only innervation of CN VII and XII
A 47-year-old male patient presents with difficulty chewing, dysphagia, regurgitation, chokinng, slurred speech, weakness of the soft palate and an absent gag reflex. You suspect:
a) Pseudobulbar palsy of CN IX, XI and XII
b) Bulbar palsy of CN IX, X, VII, XII
c) Pseudobulbar palsy of CN IX, X, XI, VII
d) Bulbar palsy of CN IX, X, XI, XII
d) Bulbar palsy of CN IX, X, XI, XII
You grab a deliciously fresh buffalo wing hot out of the fryer and immediately drop it. This sensory input of pain and temperature are relayed to:
a) Ipsilateral cerebellar cortex
b) Ipsilateral and contralateral cerebral cortices
c) Contralateral cerebral cortex
d) Contralateral cerebellar cortex
c) Contralateral cerebral cortex
T/F:
Pressure and touch are projected bilaterally to the ipsilateral and contralateral cerebral cortices.
True: This makes sense due to the increased neural requirement to determine varying levels of pressure and touch sensation
CN III innervates the constrictor of pupil and ciliary body via the following pathway:
a) Edinger-Westphal nucleus (EWN) in pons > pterygopalatine ganglion
b) Lacrimal nucleus of pons > pterygopalatine ganglion
c) EWN in midbrain > ciliary ganglion
d) Dorsal motor nucleus of CN X in medulla > Ciliary ganglion
c) EWN in midbrain > ciliary ganglion
Which two brainstem nuclei follow CN VII?
a) EWN and inferior salivatory nucleus
b) Superior and inferior salivatory nuclei
c) EWN and lacrimal nucleus
d) Lacrimal and superior salivatory nuclei
d) Lacrimal and superior salivatory nuclei
The lacrimal and nasal glands are innervated by fibers leaving which ganglion?
a) Pterygopalatine
b) ciliary
c) Submandibular
d) otic
a) pterygopalatine
The submandibular and sublingual glands are innervated by fibers leaving which ganglion?
a) Ciliary
b) Pterygopalatine
c) glottomandibular
d) submandibular
d) submandibular
The parotid gland is innervated via the _____ _____ nucleus and _____ ganglion.
a) Inferior salivatory, otic
b) Superior salivatory, otic
c) Inferior salivatory, submandibular
d) Superior salivatory, submandibular
a) Inferior salivatory, otic
PSNS fibers of CN X innervate the following:
a) heart, bladder, erectile tissue
b) Heart, bronchial tree, small and large intestine
c) Heart, bronchial tree, stomach, small and large intestine
d) Heart, bronchial tree, small/large intestine, stomach, bladder
c) Heart, bronchial tree, stomach, small and large intestine
The large intestine receives dual PSNS innervation from which two sources?
a) CN IX and XI
b) CN XI and pelvic splanchnic
c) CN X and pelvic splanchnic
d) CN X and trunk ganglion
c) CN X and pelvic splanchnic
Mydriasis would be caused by the ____ ____ muscle which is innvervated by the SNS fibers following V1 to the long ____ nerve.
a) Pupil sphincter, ciliary
b) Pupil terminator, ciliary
c) Pupil dilator, optic
d) Pupil dilator, ciliary
d) Pupil dilator, ciliary
Which muscle aids the levator palpebrae?
a) Beuller muscle
b) Kueller muscle
c) Miller muscle
d) Mueller muscle
d) Mueller muscle
The olfactory nerve enters the skull via this “sieve” bone.
a) Cribriform plate of Sphenoid
b) Sella turcica
c) superior orbital fissure
d) Cribriform plate of ethmoid
d) Cribriform plate of ethmoid
A lesion near the calcarine fissure would cause issues with what?
a) Vision
b) Smell
c) Memory
d) gustation
a) vision
This fissure separates the occipital visual cortices. Witwer loves to throw some rando term he had on a slide once that relates to an area more commonly known. Calcar means “spur,” and a spur in your eye would affect vision. Or remember as Calcareye fissure
Which nerve is the affarent limb of the pupillary light reflex AND accomodation?
a) Olfactory
b) Oculomotor
c) lingual nerve
d) Optic
d) Optic
A lesion at 1, 3, and 7 would result in what termed deficits?
1 = Ipsilateral blindess
3 = Bilateral hemianopia
7 = R hemianopia w/ macular sparing
Another term for a neuroectodermal retinal tumor is?
Retinoblastoma
What is the propensity that a retinoblastoma will be bilateral?
40%
Intrinsic muscles of the eye are innervated by which CN?
CN III
Extrinsic muscles of the eye are innervated by which CNs?
CN III, IV, VI
Horner’s syndrome is characterised by?
Ptosis, miosis and anhydrosis
CN III is the efferent limb of which two phenomenon?
Pupillary light reflex and accommodation
When the ciliary muscle is relaxed this ____ zonular fibers, allowing you to see ____.
a) pulls, Everywhere
b) loosens, far
c) tightens, far
d) pulls, peripherally
c) tightens, far
Fill in this image with corresponding eye movements and muscles
Fill in testing parameters
The physical exam of near reaction has three separate occurences, list them.
1) Both medial rectus muscles adduct eyes (convergence)
2) Pupillary constriction (direct and concensual)
3) Ciliary muscle constricts, loosening zonula fibers resulting in convexity of lens for near focus
CN III, IV and VI move the eyes, but to synchronously move them together requires input from _____ peripheral nerves and which CN?
a) pressure, VII
b) fine touch, V
c) proprioceptive, VIII
d) temperature, VII
c) proprioceptive, VIII
In MS, injury to the medial longitudinal fasciculus can cause paralysis of CN III, IV or VI or combination, leading to what?
intranuclear ophthalmoplegia (parlaysis of EOMs) leading to double vision and nystagmus
What occurs with transtentorial herniation and what is effected?
Transtentorial herniation aka Uncal Herniation is a herniation of the medial tip of the temporal lobe against the tentorium. This compresses CN III and causes:
1) fixed and dilated pupils
2) Paralysis (eyes deviated down and out)
Diabetic oculomotor paralysis causes similar sxs compared to uncal herniation except that the ____ ____ is spared.
Pupillary reflex sparing
Transtentorial or Uncle herniation causes fixed/dilated pupils and muscle palsy causing eye deviated down and out.
Oculomotor paralysis will not allow the eye to perform what movements?
a) look laterally or up
b) Look medially and down
c) look laterally, up or down
d) look medially, up or down
d) look medially, up or down
T/F:
CN III paralysis can cause diplopia in more than one direction (i.e. horizontally and vertically)?
True
Paralysis of accommodation is know as:
a) ptosis
b) miosis
c) mydriasis
d) cycloplegia
d) cycloplegia
What is the primary, secondary and tertiary movements of the superior oblique muscle?
a) intortion, depression, abduction
b) extortion, depression, abduction
c) extortion, elevation, adduction
d) intortion, elevatin, adduction
a) intortion, depression, abduction
A patient with a brain stem tumor compressing CN III usually present with:
a) HA, hearing loss, dizziness and double vision
b) loss of facial sensation, HA, memory loss
c) memory loss, hearing loss, vision loss
a) HA, hearing loss, dizziness and double vision
Which CN that innervates the calvarium is susceptible to trauma due to its long length?
a) CN II
b) CN VI
c) CN IV
d) CN VII
c) CN IV
What is the most common cause of vertical strabismus?
Damage to the trochlear nerve, although it is rarely damaged in isolation unless due to tumor of nerve
The trigeminal nerve provides:
a) facial, oral and nasal cavity sensation
b) facial, oral and nasal cavity sensation as well as salivary
c) facial, oral and nasal cavity sensation along with mastication
d) facial sensation and mastication
c) facial, oral and nasal cavity sensation along with mastication
Which branch or branches of the trigeminal nerve pass through the cavernous sinus?
a) V1, V2, V3
b) V1, V3
c) V1
d) V1, V2
e) V2, V3
d) V1, V2
V3 of the trigeminal nerve passes through which foramen?
a) Rotundum
b) Ovale
c) Spinosum
d) veiniosum
e) lameosum
b) Ovale
**V2 passes through rotundum
PSNS components of CNs ___, ___, ___ end up with branches of CN ___ after synapsing in their motor ganglion.
CN III, VII, IX
V (trigeminal)
CN V provides pain, temperature, touch and proprioception to V1, V2 and V3. Which exam methods would you use to test V1 and V2?
V1: Cotton wisp
V2: pin prick test
Which CN carries pain, temp, touch and position (but not taste) to the anterior 2/3 of the tongue?
V3 of CN V (Pizza mouth)
The corneal blink reflex pathway can have TWO afferent limbs which are?
Corneal reflex pathway via V1 OR optical reflex pathway via CN II from bright light
*Absent in infants < 9 months
** direct and consensual reflex
How would you test motor function of CN V?
Palpate masseter and temporalis during teeth clenching
The jaw jerk reflex afferent and efferent limbs are?
Afferent sensory CN V
Efferent motor V3
*This reflex is usually only able to be seen or is pronounced in upper motor neuron lesions
Cavernous sinus syndrome affects which CNs?
This leads to what sxs?
Paralysis of V1, V2 cheek, CN III and IV
Potential for loss of;
- corneal reflex V1 afferent
- deviation of jaw to weak side due to paralysis of lateral pterygoid muscle
- hyperacusis secondary to paralyzed tensor tympani
- Horner’s syndrome
- numbness from V1 and V2
- ophthalmoplegia of EOMs
The ____ nerve branches off of ___, and is used in _____ nerve blocks at the entrance of the ____ alveolar nerve in the ____ foramen.
alveolar, V3, dental, inferior, mandibular
*V3 is also referred to as the mandibular nerve and can encompass the alveolar and lingual nerve
You have a patient that presents with jaw pain from a barfight. You do not suspect a fx b/c there is no ecchymosis inferiorly in the neck where the blood would drain. This is an incorrect assumption b/c?
The mylohyoid muscle acts as a muscular diaphragm confining blood from mandibular fxs to the floor of the mouth.
The mylohyoid muscle is innervated by?
mandibular nerve aka V3
Which branch of the trigeminal nerve carries motor and sensory?
Only V3
Taste from the anterior 2/3 of the tongue is provided by the ____ nerve via the ____ ____ which is a branch of the ____ nerve.
lingual, chorda tympani, facial
*Lingual nerve also carries PSNS/SNS motor fibers to submandibular gland
The medial and lateral pterygoid muscles are innervated by?
V3 of trigeminal
The masseter and temporalis are innervated by?
V3 of trigeminal
The parotid gland is innervated by which nerve pathway?
From CN IX > lesser petrosal nerve > otic ganglion > auriculotemporal nerve > parotid gland
Which nerve has a long course in addition to VN IV, is the most common ISOLATED muscle palsy and causes inability to look latterally?
Abducens CN VI
Which CN is responsible for muscles of facial expression (especially orbicularis oris and oculi)
Facial nerve CN VII
CN VII provides which functions?
a) taste, temperature, proprioception
b) salivation, lacrimation, expression
c) Salivation, lacrimation, taste, expression
d) salivation, lacrimation, expression, taste, pressure
c) Salivation, lacrimation, taste, expression
