Cranial nerves

Question 1

What nerve is at risk during excision of a submandibular salivary gland?

Answer 1

Mandibular branch of facial nerve
Lingual nerve
Hypoglossal nerve

Question 2

What structures are contained in the cavernous sinus?

Answer 2

Occulomotor nerve 
Trochlear nerve 
Abducens nerve 
Ophthalmic nerve 
Maxillary nerve 
Internal carotid

Question 3

Name all 12 cranial nerves?

Answer 3

1-olfactory 
2-optic
3-occulomotor
4-trochlear
5-trigeminal 
6-abducens 
7-facial
8-vetibulocochlear
9-glossopharyngeal 
10-vagus 
11-accessory  
12- hypoglossal

Question 4

After a superficial parotidectomy the patient reports cheek going red and sweating, what nerve has been damaged?

Answer 4

Auriculotemporal branch of trigeminal nerve

Question 5

What nerve carries parasympathetic innervation to submandibular salivary gland proximal to tongue?

Answer 5

Chorda tympani carried by lingual nerve

Question 6

What muscles does the facial nerve supply?

Answer 6

Muscles of facial expression
Posterior belly of digastric
Stylohyoid and stapedius muscles

Question 7

A patient has a head injury and damages foramen rotundum at base of skull- what nerve is damaged?

Answer 7

Maxillary division of trigeminal nerve

Question 8

What nerve would be damaged if the foramen ovale was affected?

Answer 8

Mandibular division of trigeminal nerve

And Optic ganglion

Question 9

What is supplied by the mandibular branch of the trigeminal nerve?

Answer 9

Motor component to muscles of mastication, mylohyoid, anterior belly of digastric, tensor veil palate I and tensor tympani
Sensory innervation to the mandibular dentition.

Question 10

What nerves supply the digastric muscle?

Answer 10

Posterior belly supplied by facial nerve.

Anterior belly supplied by trigeminal nerve vis the mylohyoid nerve

Question 11

What muscle is supplied by the abducens nerve?

Answer 11

Lateral rectus

Question 12

What vessel is associated with trigeminal neuralgia?

Answer 12

Superior cerebellar artery

Question 13

After an IDB patient complains of a watery eye and difficulty blinking, what nerve is affected?

Answer 13

Zygomatic branch of facial nerve.

Question 14

What structures are derived from the 4th pharyngeal arch?

Answer 14

Pharyngeal constrictors, levator veli palatini, cricothyroid, larynx and vagus nerve

Question 15

What is the function of the olfactory nerve?

Answer 15

Special sensory supply for smell and advanced aspects of taste

Question 16

What is the function of the optic nerve?

Answer 16

Special sensory information for vision and pupil responses

Question 17

What is the function of the occulomotor nerve?

Answer 17

Motor innervation to extra occlular muscles
Parasympathetic supplied the sphincter papillae for constrict the pupil.
Sympathetic fibres help raise eyelid.

Question 18

What is the function of the trochlear nerve?

Answer 18

Purely somatic function of the superior oblique muscle which depresses the eyeball

Question 19

What is the function of the trigeminal nerve?

Answer 19

Sensation over face, oral mucosa, conjunctiva, tympanic membrane and sinuses.
Supplies corneal reflex, jaw jerk and taste sensation.
Motor division supplies MoM.
Sensation fibres to anterior 2/3rd of tongue and secretomotor supply to submandibular and sublingual and lacrimal glands

Question 20

What are the branches of the trigeminal nerve?

Answer 20

Ophthalmic branch sensory from the superior orbital fissure.
Maxillary branch sensory from the foramen rotundum
Mandibular branch motor and sensory from foramen ovale.

Question 21

What is the function of the abducens nerve?

Answer 21

Somatic motor function to lateral rectus muscle allowing the eyeball to abduct

Question 22

What is the function of the facial nerve?

Answer 22

Somatic motor supply to muscles of facial expression.
Taste sensation for anterior 2/3rd of tongue via chorda tympani
Branches to stapedius muscles of middle ear.

Question 23

What is the function of the vestibulocochlear nerve?

Answer 23

Sensory function controlling hearing and balance

Question 24

What is the function of the glossopharyngeal nerve?

Answer 24

Sensory to posterior 1/3rd of tongue and pharynx
Taste to posterior 1/3rd of tongue
Motor supply to stylopharyngeus.

Question 25

What is the function of the vagus nerve?

Answer 25

Wide parasympathetic distribution to viscera of upper abdomen.
Motor supply to soft palate, pharyngeal and laryngeal muscles.

Question 26

What is the function of the accessory nerve?

Answer 26

Motor supply to trapezius and sternomastoid muscles

Question 27

What is the function of the hypoglossal nerve?

Answer 27

Motor supply to muscles of the tongue allowing for protrusion

Question 28

What are the potential extra cranial causes of facial sensory loss?

Answer 28

Trauma 
Inflammatory - osteomyelitis 
Neoplastic carcinoma of antrum or nasopharynx
Metastatic tumours
Leukaemia

Question 29

What are the potential intra cranial causes of facial sensory loss?

Answer 29

Trauma 
Inflammatory 
MS, sarcoidosis 
Neoplastic cerebral tumours 
Vascular disease
Paget’s 
Medications

Question 30

What is Bell’s palsy?

Answer 30

It is the most common acute LMN lesion caused by inflammation of the facial nerve which may be associated with infection most commonly HSV leading to demyelination and oedema usually in he stylomastoid canal.

Question 31

How is Bell’s palsy managed?

Answer 31

Systemic corticosteroids 20mg 4x daily for 5 days then reduce for following 4 days.
Eye patch to protect cornea and eye drops for dryness.

Question 32

A patient suffers damage to accessory nerve, which muscle would you use to assess the damage?

Answer 32

Trapezius muscle - shrugging shoulders

Question 33

You are planning on restoring an upper right 1st molar, which nerve will your local anaesthetic aim to anaesthetise?

Answer 33

Superior posterior alveolar nerve

- supplies sensory inner action to molar teeth, gingivae and periosteum.