Cranial Nerves and Skull

Question 1

Superior orbital fissure

Answer 1

Occulomotor (III), trochlear (IV), abducens (VI), ophthalmic (V), superior ophthalmic vein

Question 2

Optic canal

Answer 2

Optic nerve (II), ophthalmic artery

Question 3

Optic canal

Answer 3

Optic nerve (II)

Question 4

foramen ovale

Answer 4

mandibular (V), accessory meningeal artery

Question 5

foramen ovale

Answer 5

mandibular (V)

Question 6

internal auditory meatus

Answer 6

facial (VII), vestibulocochlear (VIII), vestibular ganglion, labyrinth artery

Question 7

jugular foramen

Answer 7

glossopharyngeal (IX), vagus (X), cranial part of accessory (XI), sigmoid sinus, meningeal vessels, inferior petrosal sinus

Question 8

jugular foramen

Answer 8

glossopharyngeal (IX), vagus (X), accessory (XI)

Question 9

hypoglossal canal

Answer 9

hypoglossal nerve (XII)

Question 10

Trochlear nerve function (IV)

Answer 10

Motor control of Lateral Rectus, Moves the eye laterally.

Question 11

foramen spinosum

Answer 11

middle meningeal artery, middle meningeal vein

Question 12

foramen magnum

Answer 12

vertebral arteries, medulla oblongata, spinal part of accessory (XI), dural veins, anterior and posterior spinal arteries

Question 13

Aducent Nerve function (VI)

Answer 13

Motor control of the superior oblique, moves the eye downwards

Question 14

Trigeminal nerve function (V)

Answer 14

Ophthalmic branch (V1): Sensory innervation of the forehead, conjunctiva and upper eyelid
Maxillary branch (V2): Sensory innervation of the lower eyelid, cheek, upper teeth and hard palate
Mandibular branch (V3): Sensory innervation of the jaw, temple, lower teeth, anterior 2/3 of the tongue (sensation not taste) and motor control of the muscles of mastication

Question 15

Facial Nerve function (VII)

Answer 15

Motor control of the muscles of facial expression, buccinator, stapedius
Sensory: taste to anterior 2/3 of the tongue
Parasympathetic: lacrimal, parotid, sublingual and submandibular gland

Course through the internal acoustic meatus, middle ear and parotid gland

Question 16

Auditory nerve (VI) course

Answer 16

With the facial nerve in the internal auditory meatus

Question 17

Glossopharyngeal nerve (IX)

Answer 17

Sensory innervation of the oropharynx (gag reflex)

Parasympathetic innervation of the parotid gland

Question 18

What are the effects of damage to CNs III, IV and VI?

CN III: Oculomotor nerve:

Answer 18

Loss of upward, downward and medial movement of the eye
Ptosis (drooping of eyelid)
Pupillary dilation (paralysis of sphincter pupillae)
Diplopia (double vision)
CN IV: Trochlear nerve:

Diplopia upon looking downwards or medially
CN VI: Abducens nerve:

Loss of lateral movement of the eye
Diplopia upon looking to the affected side

Question 19

What is acoustic neuroma?

Answer 19

Benign tumour on the either/or the cochlear and vestibular branches of the vestibulocochlear nerve
Compression can lead to hearing and/or balance loss

Question 20

Bones of the skull

Answer 20

frontal, occipital, parietal, temporal, zygoma, sphenoid, ethmoid, nasal, maxilla, mandible

Question 21

Skull sutures

Answer 21

coronal, sagittal Pareto-occipital sutures, bregma, pterion, lambdoidal

Question 22

Vagus Nerve function (X)

Answer 22

Motor control of the muscles of the palate, pharynx, larynx
Sensory supply to the larynx, respiratory system, fore- and midgut
Parasympathetic supply to foregut and midgut, thoracic and most abdominal viscera

Somatic sensory innervation of external acoustic meatus

Question 23

Spinal Accessory function (XI)

Answer 23

Motor control of sternomastoid and trapezius, course through the posterior triangle

Question 24

Hypoglossal Nerve function (XII)

Answer 24

Motor control of intrinsic and extrinsic muscles of the tongue