Cranial Nerve 2

Question 1

What are 3 subdivisions of trigeminal nerve?

Answer 1

1. Ophthalmic: V1
2. Maxillary: V2
3. Mandibular: V3

Question 2

What is function of opthalamic nerve?

Answer 2

sensory information from:

1. scalp
2. forehead
3. nose
4. upper eyelid
5. conjunctiva
6. cornea of the eye

Question 3

What is function of maxillary nerve?

Answer 3

• sensory information from
  1. lower eyelid
  2. cheek
  3. nares
  4. upper lip
  5. upper teeth
  6. gums

Question 4

What is sensory function of mandibular nerve?

Answer 4

• sensory information from
  1. chin
  2. jaw
  3. lower lip
  4. mouth
  5. lower teeth
  6. gums.

Question 5

What is the motor function of the mandibular nerve?

Answer 5

• to the
  1. muscles of mastication (masseter, temporal muscle and the medial/lateral pterygoids)
  2. tensor tympani
  3. tensor veli palatini
  4. mylohyoid
  5. digastric

Question 6

What muscle does raised eyebrows test?

Answer 6

assesses frontalis

Question 7

What muscle does closed eyes assess?

Answer 7

orbicular oculi

Question 8

What muscle does blown out cheeks assess?

Answer 8

orbicularis oris

Question 9

What muscle does smiling assess?

Answer 9

levator anguli oris and zygomaticus major

Question 10

What muscle does pursed lips assess?

Answer 10

orbicularis oris and buccinator

Question 11

What can facial nerve palsy present with?

Answer 11

unilateral weakness of the muscles of facial expression

Question 12

What does facial nerve palsy caused by LMN lesion present with?

Answer 12

weakness of all ipsilateral muscles of facial expression, due to the loss of innervation to all muscles on the affected side

Question 13

What is most common cause of lower motor neuron facial palsy?

Answer 13

Bell’s palsy

Question 14

How does facial nerve palsy caused by UMN lesion?

Answer 14

unilateral facial muscle weakness

Question 15

What muscle is spared in facial palsy caused by UMN lesion and why?

Answer 15

upper facial muscles partially spared because of bilateral cortical representation (resulting in forehead/frontalis function being somewhat maintained)

Question 16

What is most common cause of UMN lesion facial palsy?

Answer 16

stroke

Question 17

What vibration is tuning fork in Rinne’s?

Answer 17

512Hz

Question 18

What is Rinne’s positive?

Answer 18

can hear the sound suggests air conduction is better than bone conduction, which is what would be expected in a healthy individual

Question 19

What is normal result of Rinne’s?

Answer 19

air conduction > bone conduction (Rinne’s positive)

Question 20

What is sensorineural deafness with Rinne’s test?

Answer 20

air conduction > bone conduction (Rinne’s positive) – due to both air and bone conduction being reduced equally

Question 21

What is conductive deafness in Rinne’s?

Answer 21

bone conduction > air conduction (Rinne’s negative)

Question 22

What is normal result with Weber’s?

Answer 22

sound is heard equally in both ears

Question 23

What is the sensorineural deafness in Weber’s?

Answer 23

sound is heard louder on the side of the intact ear

Question 24

What is conductive deafness in Weber’s?

Answer 24

sound is heard louder on the side of the affected ear

Question 25

What is conductive hearing loss?

Answer 25

sound is unable to effectively transfer at any point between the outer ear, external auditory canal, tympanic membrane and middle ear (ossicles)

Question 26

What are causes of conductive hearing loss?

Answer 26

1. excessive ear wax 2. otitis externa 3. otitis media 4. perforated tympanic membrane 5. otosclerosis

Question 27

What is sensorineural hearing loss?

Answer 27

due to dysfunction of the cochlea and/or vestibulocochlear nerve

Question 28

What are the causes of sensorineural hearing loss?

Answer 28

1. increasing age (presbycusis) 2. excessive noise exposure 3. genetic mutations 4. viral infections (e.g. cytomegalovirus) 5. ototoxic agents (e.g. gentamicin)

Question 29

What is the motor function of the glossopharyngeal nerve?

Answer 29

stylopharyngeus muscle which elevates the pharynx during swallowing and speech

Question 30

What is the sensory function of glossopharyngeal nerve?

Answer 30

transmits sensory information that conveys taste from the posterior third of the tongue

Question 31

What do the visceral sensory fibres of glossopharyngeal nerve do?

Answer 31

mediate the afferent limb of the gag reflex

Question 32

What is the motor function of the vagus nerve?

Answer 32

to several muscles of the mouth which are involved in the production of speech and the efferent limb of the gag reflex

Question 33

What is the motor function of accessory nerve?

Answer 33

sternocleidomastoid and trapezius muscles

Question 34

What is the motor function of the hyopglossal nerve?

Answer 34

to the extrinsic muscles of the tongue (except for palatoglossus which is innervated by the vagus nerve)

Question 35

What does hypoglossal nerve palsy look like?

Answer 35

1. atrophy of the ipsilateral tongue | 2. deviation of the tongue when protruded towards the side of the lesion

Question 36

What causes hypoglossal nerve palsy?

Answer 36

due to the overaction of the functioning genioglossus muscle on the unaffected side of the tongue