Cranial nerves 0425

Question 1

medial location at brain stem

Answer 1

III, VI, XII

Question 2

pineal gland

Answer 2

melatonin secretion, circadian rhythm

Question 3

superior colliculi

Answer 3

EYES - conjugate vertical gaze center

Question 4

inferior colliculi

Answer 4

EARS - auditory center

Question 5

lesion of superior colliculus

Answer 5

PARINAUD SYNDROME.
paralysis of conjugate vertical gaze.
ex: pinealoma

Question 6

CN I olfactory

Answer 6

smell

*only CN without thalamic relay to cortex

Question 7

CN II optic

Answer 7

sight

Question 8

CN III oculomotor

Answer 8

eye movement (SR, IR, MR, IO).
pupillary constriction (e-w nucleus, muscarinic R).
accommodation.
eye lid opening (levator palpebrae).

Question 9

CN IV trochlear

Answer 9

eye movement (SO)

Question 10

CN V trigeminal

Answer 10

mastication.
facial sensation (ophthalmic, maxillary, mandibular divisions).

Question 11

CN VI abducens

Answer 11

eye movement (LR)

Question 12

CN VII facial

Answer 12

facial movement.
taste from ant 2/3 tongue.
lacrimation.
salivation (submand and sublingual glands).
eyelid closing (orbicularis oculi).
stapedius m. in ear.

Question 13

CN VIII vestibulocochlear

Answer 13

hearing, balance

Question 14

CN IX glossopharyngeal

Answer 14

taste from post 1/3 tongue.
swallowing.
salivation (parotid gland).
monitoring carotid body and sinus chemo- and baroreceptors.
stylopharyngeus (elevates pharynx, larynx).
sensation in upper pharynx, post 1/3 tongue, tonsils, middle ear.

Question 15

CN X vagus

Answer 15

taste from epiglottic region.
swallowing.
palate elevation.
midline uvula.
talking.
coughing.
thoracoabdominal viscera.
monitoring aortic arch chemo- and baroreceptors.

Question 16

CN XI accessory

Answer 16

head turning, shoulder shrugging - sternocleidomastoid, trapezius.

Question 17

CN XII hypoglossal

Answer 17

tongue movement

Question 18

CN nuclei - midbrain

Answer 18

III, IV

Question 19

CN nuclei - pons

Answer 19

V, VI, VII, VIII

Question 20

CN nuclei - medulla

Answer 20

IX, X, XII

Question 21

CN nuclei - spinal cord

Answer 21

XI (accessory nucleus)

Question 22

general features of CN nuclei

Answer 22

located in tegmentum of brain stem (btn dorsal and ventral portions).

lateral nuclei = sensory. from alar plate.
medial nuclei = motor. from basal plate.
*sulcus limitans separates lateral from medial nuclei

Question 23

vagal nuclei in brainstem

Answer 23

1. nucleus solitarius
2. nucleus ambiguus
3. dorsal motor nucleus

Question 24

nucleus Solitarius

Answer 24

visceral Sensory info (taste, baroreceptors, gut distention).

CN VII, IX, X

Question 25

nucleus aMbiguus

Answer 25

Motor innervation of pharynx, larynx, upper esoph (swallowing, palate elevation, eff limb of gag reflex). CN IX, X, XI

Question 26

dorsal motor nucleus

Answer 26

sends autonomic (parasymp) fibers to heart, lungs, upper GI (decrease HR, increase secretions/peristalsis)

Question 27

cribriform plate

Answer 27

CN I

Question 28

middle cranial fossa - through sphenoid bone

Answer 28

CN II - VI

Question 29

optic canal

Answer 29

CN II, ophthalmic a., central retinal v.

Question 30

superior orbital fissure

Answer 30

CN III, IV, V1, VI, ophthalmic vein, symp fibers

Question 31

foramen rotundum

Answer 31

CN V2

Question 32

foramen ovale

Answer 32

CN V3

Question 33

foramen spinosum

Answer 33

middle meningeal a.

Question 34

posterior cranial fossa - through temporal or occipital bone

Answer 34

CN VII - XII

Question 35

internal auditory meatus

Answer 35

CN VII, VIII

Question 36

jugular foramen

Answer 36

CN IX, X, XI, jugular vein

Question 37

hypoglossal canal

Answer 37

CN XII

Question 38

foramen magnum

Answer 38

spinal roots of CN XI, brainstem, vertebral aa.

Question 39

pathway of CN V divisions

Answer 39

V1: Superior orbital fissure. V2: foramen Rotundum. V3: foramen Ovale. "Standing Room Only"

Question 40

corneal (blink) reflex

Answer 40

aff: V1 ophthalmic (nasociliary branch) eff: VII (temporal branch - orbicularis oculi)

Question 41

lacrimation reflex

Answer 41

aff: V1 eff: VII (greater petrosal n.)

Question 42

jaw jerk reflex

Answer 42

aff: V3 (sensory - muscle spindle from masseter m.) eff: V3 (motor - masseter m.)

Question 43

pupillary reflex

Answer 43

aff: II eff: III

Question 44

gag reflex

Answer 44

aff: IX eff: IX, X

Question 45

CN XII lesion (LMN)

Answer 45

tongue deviates TOWARD side of lesion due to weakened tongue mm. on affected side

Question 46

CN V motor lesion

Answer 46

jaw deviates TOWARD side of lesion due to unopposed force from opposite pterygoid when opening mouth.

Question 47

CN X lesion

Answer 47

uvula deviates AWAY from side of lesion. weak side collapses and uvula points away.

Question 48

CN XI lesion

Answer 48

weakness turning head to contra side of lesion (SCM). shoulder drop on ipsi side (trapezius).

Question 49

conductive hearing loss

Answer 49

abnormal Rinne test (bone > air). | Weber test localizes to affected ear.

Question 50

sensorineural hearing loss

Answer 50

normal Rinne test (air > bone)> | Weber test localizes to UNaffected ear.

Question 51

mastication

Answer 51

3 mm. close jaw: Masseter, teMporalis, Medial pterygoid. 1 m. opens jaw: lateral pterygoid. ALL innervated by V3.

Question 52

UMN lesion CN VII

Answer 52

(precentral gyrus or connection btn cortex and facial nucleus) - contralateral paralysis of lower face (below brow). upper face has bilateral innervation. can still raise eyebrows.

Question 53

LMN lesion CN VII

Answer 53

ipsi paralysis of upper and lower face

Question 54

Bell's palsy

Answer 54

complete destruction of facial nucleus or branchial efferent fibers (facial nerve proper). peripheral ipsi facial paralysis with inability to close eye on affected side.

Question 55

causes of Bell's palsy

Answer 55

most are idiopathic with gradual recovery. also: AIDS, Lyme disease, Herpes simplex, Sarcoidosis, Tumors, Diabetes "ALexander graHam BELL with STD"