Cranial Nerves 1

Question 1

What are the 7 modalities?

Answer 1

• General somatic efferent (orbital and tongue muscles)
• Special visceral efferent (muscles of pharyngeal arches)
• General visceral efferent (eye, saliva, heart, lung, gut, parasympathetic)
• General visceral afferent
• Special visceral afferent (taste)
• General somatic afferent
• Special somatic afferent (sight, hearing, balance)

Question 2

What is the function of the Olfactory nerve CN I?

Answer 2

Sense of smell/olfaction (special visceral afferent)

Question 3

What is the function of the Optic nerve CN II?

Answer 3

Sense of sight/vision

special somatic afferent

Question 4

What is the function of the Oculomotor nerve CN III?

Answer 4

PRIMARY:
Motor: eye movements
(general somatic efferent)

ADDITIONAL: parasympathetic (general visceral efferent)

Question 5

What is the function of the Trochlear nerve CN IV?

Answer 5

Motor: eye movements (general somatic efferent)

Question 6

What is the function of the Trigeminal nerve CN V?

Answer 6

PRIMARY:
Sensation: head and cavities
(general somatic afferent)

Motor: muscles of mastication
(special visceral effent)

ADDITIONAL:
Carrier of autonomic fibres

Question 7

What is the function of the Abducens nerve CN VI?

Answer 7

Motor: eye movements (general somatic efferent)

Question 8

What is the function of the Facial and Nerves Intermedius CN VII?

Answer 8

PRIMARY:
Motor: muscles of facial expression (special visceral efferent)

ADDITIONAL:
Parasympathetic (general visceral efferent)
Anterior 2/3 Taste/Gustation
(special visceral afferent)

Question 9

What is the function of the Vestibulocochlear nerve CN VIII?

Answer 9

Hearing and balance

special somatic afferent

Question 10

What is the function of the Glossopharyngeal nerve CN IX?

Answer 10

PRIMARY:
General sensation: (posterior 1/3) tongue and oropharynx
(general somatic afferent)

ADDITIONAL:
Parasympathetic (general visceral efferent)
Posterior 1/3 Taste/Gustation (special visceral afferent)

Question 11

What is the function of the Vagus nerve CN X?

Answer 11

PRIMARY:
General sensation: pharynx and larynx
(general somatic afferent)
Parasympathetic heart, lungs, GI tract (general visceral efferent)

ADDITIONAL:
Motor to pharynx and larynx
(special visceral efferent)

Question 12

What is the function of the Spinal accessory nerve CN XI?

Answer 12

Motor: sternocleidomastoid and trapezius
(special visceral efferent/general somatic efferent)
*ongoing debate

Question 13

What is the function of the Hypoglossal nerve CN XII?

Answer 13

Motor: tongue (general somatic efferent

Question 14

Where on the base of the skull does the Olfactory nerve (CN I) pass through?

Answer 14

Cribriform plate foramina

Question 15

Where on the base of the skull does the Optic nerve (CN II) pass through?

Answer 15

Optic canal

Question 16

Where on the base of the skull does the Oculomotor nerve (CN III) pass through?

Answer 16

Superior orbital fissure

Question 17

Where on the base of the skull does the Trochlear nerve (CN IV) pass through?

Answer 17

Superior orbital fissure

Question 18

Where on the base of the skull does the Trigeminal nerve (CN V) pass through?

Answer 18

Superior orbital fissure
Foramen rotundum
Foramen ovale

Question 19

Where on the base of the skull does the Abducens nerve (CN VI) pass through?

Answer 19

Superior orbital fissure

Question 20

Where on the base of the skull does the Facial nerve (CN VII) pass through?

Answer 20

Internal acoustic meatus

Question 21

Where on the base of the skull does the Vestibulocochlear nerve (CN VIII) pass through?

Answer 21

Internal acoustic meatus

Question 22

Where on the base of the skull does the Glossopharyngeal nerve (CN IX) pass through?

Answer 22

Jugular foramen

Question 23

Where on the base of the skull does the Vagus nerve (CN X) pass through?

Answer 23

Jugular foramen

Question 24

Where on the base of the skull does the Spinal accessory nerve (CN XI) pass through?

Answer 24

Jugular foramen

Question 25

Where on the base of the skull does the Hypoglossal (CN XII) pass through?

Answer 25

Hypoglossal canal

Question 26

Where is the oculomotor nuclei located?

Answer 26

In the mid brain

Question 27

Where is the trochlear nuclei located?

Answer 27

In the mid brain

Question 28

Where does the abducens nuclei located?

Answer 28

In the pons

Question 29

What modalities are the oculomotor, trochlear, and abducens nerve associated with?

Answer 29

General somatic efferent

Question 30

What vessels does the CN III (oculomotor) nerve pass between? What is the clinical significance?

Answer 30

Passes between the posterior cerebral and superior cerebellar arteries before lying close to the posterior communicating artery.

Aneurysms of those vessels may compress CN III

Question 31

What does CN III innervate?

Answer 31

• Extraocular muscles: medial rectus, superior rectus, inferior oblique, inferior rectus
• Levator palpebrae superioris
• Parasympathetic from Edinger-Westphal nucleus
• Sympathetic from the carotid plexus to supply the smooth muscle component of elevator palpebrae superioris

Question 32

What does CN IV innervate?

Answer 32

• Superior oblique (turcs the eye downward and laterally)

Question 33

What does CN VI innervate?

Answer 33

• Lateral rectus (to abduct the eye)

Question 34

What nerves are associated with the ciliary ganglion?

Answer 34

• Parasympathetics coming from Edinger-Westphal nucleus via CN III will synapse
• Sympathetics coming from the carotid plexus will pass through

Question 35

What are the symptoms of Horner’s syndrome?

Answer 35

• Miosis (constriction of pupil)
• Ptosis (droopy eyelid)
• Anhydrosis
• Flushed face
• • directly related to actions of sympathetic chain