cranial nerves

Question 1

only CN to attach to the pons

Answer 1

trigeminal nerve

Question 2

intracranial course of the trigeminal nerve

Answer 2

inferior to the edge of the tentorium cerebelli between the posterior and middle cranial fossae

Question 3

which foramen does CNV1 enter

Answer 3

superior orbital fissure

Question 4

which foramen does CNV2 enter

Answer 4

foramen rotundum

Question 5

which foramen does CNV3 enter

Answer 5

foramen ovale

Question 6

superficial sensory innervation of the ophthalmic nerve

Answer 6

the upper eyelid
the cornea
the conjunctiva
the skin of the root/bridge/tip of the nose

Question 7

superficial sensory innervation of the maxillary nerve

Answer 7

the skin of the lower eyelid
the skin over the maxilla
the skin of the ala of the nose
the skin/mucosa of the upper lip

Question 8

superficial sensory innervation of the mandibular nerve

Answer 8

skin over the mandible and temporomandibular joint (not angle of the mandible)

Question 9

function of CNIII

Answer 9

eye movements (MR, IO, SR, IR)
pupil constriction
accommodation reflex
eyelid opening

Question 10

palsy of CNIII

Answer 10

ptosis
down and out
dilated, fixed pupil

Question 11

foramen that CNIII passes through

Answer 11

superior orbital fissure

Question 12

trigeminal nerve motor innvervation

Answer 12

3 pairs of jaw closing muscles: masseter, temporalis, medial pterygoid
1 pair of jaw opening muscles: lateral pterygoid
also: tensor veli palatini, tensor tympani

Question 13

sensory test of ophthalmic nerve

Answer 13

forehead
upper eyelid and tip of the nose

Question 14

sensory testing of maxillary nerve

Answer 14

mid-cheek, lower eyelid, upper lip and nostril of nose

Question 15

sensory testing of mandibular nerve

Answer 15

mid-cheek, lower lip and chin

Question 16

motor testing of trigeminal nerve

Answer 16

palpate the strength of contraction of the masseter and temporalis by asking the patient to clench their teeth
ask the patient to open their jaw against resistance

Question 17

connection to the CNS for the facial nerve

Answer 17

anterolateral at pontomedullary junction

Question 18

intracranial part of the course of the facial nerve

Answer 18

directly into internal acoustic meatus in the posterior cranial fossa

Question 19

extracranial part of the course of the facial

Answer 19

most somatic motor axons pass into the parotid gland then into 1 of the 5 branches that supple the muscles of facial expression

Question 20

chorda tympani is a branch of what nerve

Answer 20

CNVII

Question 21

what does the chorda tympani innervate

Answer 21

taste buds of the anterior 2/3rds of the tongue
parasympathetic supply to the submandibular and sublingual salivary glands

Question 22

the tiniest skeletal muscle in the body

Answer 22

stapedius

Question 23

what nerve innervates the stapedius

Answer 23

CNVII

Question 24

what does the stapedius do

Answer 24

reduces stapes movement to protect the internal ear from excessive noise

Question 25

clinically test motor function of facial nerve by asking patient to

Answer 25

frown close eyes tightly smile puff out cheeks

Question 26

glossopharyngeal connection to the CNS

Answer 26

lateral aspect of superior medulla oblongata

Question 27

intracranial part of the course of the glossopharyngeal nerve

Answer 27

directly towards jugular foramen in the posterior cranial fossa

Question 28

extracranial part of the course of the glossopharyngeal

Answer 28

axons mainly pass to or from the tongue and palate

Question 29

special sensory function of glossopharyngeal

Answer 29

the vallate papillae (with taste buds) of the posterior 1/3rd of the tongue

Question 30

parasympathetic function of glossopharyngeal

Answer 30

to the parotid salivary gland

Question 31

afferent limb of the gag reflex

Answer 31

CNIX

Question 32

general sensory function of glossopharyngeal

Answer 32

the posterior 1/3rd of the tongue mucosa of most of the nasopharynx mucosa of all of the oropharynx mucosa of some of the laryngopharynx palatine tonsil eustachian tube middle ear cavity

Question 33

vagus nerve connection to CNS

Answer 33

lateral aspect of medulla oblongata, immediately inferior to CNIX

Question 34

intracranial part of the course of the vagus nerve

Answer 34

directly towards jugular foramen in the posterior cranial fossa

Question 35

extracranial part of course of vagus nerve

Answer 35

axons supply lots of structures between the palate and the midgut

Question 36

course of the vagus nerve in the chest

Answer 36

right CNX runs along lateral aspect of trachea left CNX runs along lateral aspect of aortic arch

Question 37

clinical testing of the vagus nerve

Answer 37

ask patient to say ah- also test CNV3 - uvula should lift straight up in midline - deviates away from the lesion ask patient to swallow small amount of water - watch larynx listen to speech: hoarseness ask patient to cough

Question 38

spinal accessory nerve connection to CNS

Answer 38

via cervical spinal nerve anterior rootlets to the spinal cord

Question 39

intracranial part of the course of the spinal accessory nerve

Answer 39

ascends through foramen magnum then travels towards jugular foramen in posterior cranial fossa

Question 40

which foramen does the spinal accessory nerve pass through

Answer 40

jugular foramen

Question 41

extracranial part of the course of the spinal accessory nerve

Answer 41

axons supply sternocleidomastoid on deep surface, then continue across posterior triangle of the neck deep to investing fascia and supply the trapezius

Question 42

clinical testing of spinal accessory nerve

Answer 42

ask patient to shrug shoulders ask them to turn head to look up towards the opposite side

Question 43

hypoglossal nerve connection to CNS

Answer 43

via many rootlets that attach lateral to the pyramids of the medulla oblongata

Question 44

intracranial part of the course of the hypoglossal nerve

Answer 44

passes anteriorly towards hypoglossal canal in the posterior cranial fossa

Question 45

which foramen does the hypoglossal nerve pass through

Answer 45

hypoglossal canal

Question 46

extracranial part of the course of the hypoglossal nerve

Answer 46

descends in neck lateral to carotid sheath at level of hyoid bone it passes anteriorly towards the lateral aspect of the tongue supplies most of the muscles of the tongue

Question 47

clinical testing of the hypoglossal nerve

Answer 47

ask patient to stick tongue straight out - tongue will point towards side of lesion

Question 48

clinical testing of the optic nerve

Answer 48

light reflexes, visual field testing, snellen chart

Question 49

oculomotor testing of cranial nerves

Answer 49

extraocular eye movements