Cranial nerves

Question 1

CN I - what is the function, opening and type (sensor/motor/both)?

Answer 1

Function: smell

Opening: cribiform plate

Type: Sensory

Question 2

CN II - what is the function, opening and type (sensor/motor/both)?

Answer 2

Function: Vision

Opening: Optic canal

Type: Sensory

Question 3

CN III - what is the function, opening and type (sensor/motor/both)?

Answer 3

Function: Eye movment (SR, IR, MR, IO), pupillary constriction (sphincter pupillae: EW nucleus, M receptors), accommodation, eyelid opening (levator palpebrae)

Opening: Superior orbital fissure

Type: Motor

Question 4

CN IV - what is the function, opening and type (sensor/motor/both)?

Answer 4

Trochlear nerve

Function: Eye movement (SO)

Opening: Superior orbital fissure

Type: Motor

Question 5

CN V - what is the function, opening and type (sensor/motor/both)?

Answer 5

Trigeminal nerve -V1 ophthalmic, V2 maxillary, V3 mandibular

Function: Mastication, facial sensation, somatosensation from anterior 2/3 of tongue

Opening: V1- superior orbital fissure, V2- foramen rotundum, V3- foramen ovale

Type: Both

Question 6

CN VI - what is the function, opening and type (sensor/motor/both)?

Answer 6

Abducens nerve

Function: Eye movement

Opening: Superior orbital fissure

Type: Motor

Question 7

CN VII - what is the function, opening and type (sensor/motor/both)?

Answer 7

Facial nerve

Function: Facial movement, taste from anterior 2/3 of tongue, lacrimation and salivation (submandibular and sublingual glands), eyelid closing (orbicularis oculi), stapedius muscle in ear

Opening: internal acoustic meatus

Type: Both

Question 8

CN VIII - what is the function, opening and type (sensor/motor/both)?

Answer 8

Vestibulocochlear nerve

Function: Hearing, balance

Opening: internal acoustic meatus

Type: Sensory

Question 9

CN IX - what is the function, opening and type (sensor/motor/both)?

Answer 9

Glossopharngeal nerve

Function: Taste and somatosensation from posterior 1/3 of tongue, swallowing, salivation (parotid gland), monitor carotid body and sinus chemo- and baroreceptors, innervates stylopharyngeus (elevates pharynx and larynx)

Opening: Jugular foramen

Type: Both

Question 10

CN X - what is the function, opening and type (sensor/motor/both)?

Answer 10

Vagus nerve

Function: Taste from epiglottic region (most posterior part of tongue), swallowing, soft palate elevation, midline uvula, talking, coughing, thoracoabdominal viscera, monitoring aortic arch chemo and baroreceptors

Opening: jugular foramen

Type: Both

Question 11

CN XI - what is the function, opening and type (sensor/motor/both)?

Answer 11

Accessory nerve

Function: Head turning, shoulder shrugging (SCM, trapezius)

Opening: enters jugular magnum (spinal roots), exits jugular foramen

Type: Motor

Question 12

CN XII - what is the function, opening and type (sensor/motor/both)?

Answer 12

Hypoglossal nerve

Function: Tongue movement

Opening: hypoglossal canal

Type: Motor

Question 13

Which CNs go through the middle cranial fossa?

Answer 13

CN II-VI

Question 14

Which CNs go through the posterior cranial fossa?

Answer 14

CN VII-XII

Question 15

What goes through the optic canal?

Answer 15

CN II, ophthalmic artery, central retinal vein

Question 16

What goes through the superior orbital fissure?

Answer 16

CN III, IV, V1, VI, ophthalmic vein, sympathetic fibers

Question 17

What goes through the foramen rotundum?

Answer 17

CN V2

Question 18

What goes through the foramen ovale?

Answer 18

CN V3

Question 19

What goes through the foramen spinosum?

Answer 19

Middle meningeal artery

Question 20

What goes through the internal auditory meatus?

Answer 20

CN VII and VIII

Question 21

What goes through the jugular foramen?

Answer 21

CN IX, X, XI, jugular vein

Question 22

What goes through the foramen magnum?

Answer 22

spinal roots of CN XI, brain stem, vertebral arteries

Question 23

Which CNs have nuclei in the midbrain?

Answer 23

CN III, IV

Question 24

Which CNs have nuclei in the pons?

Answer 24

CN V-VIII

Question 25

Which CNs have nuclei in the medulla?

Answer 25

CN IX, X, XII

Question 26

Which CNs have nuclei in the spinal cord?

Answer 26

CN XI

Question 27

Which CN nuclei lie medially at brain stem?

Answer 27

CN III, IV, VI, XII

Question 28

Which CNs make up the nucleus solitarius and what is the function?

Answer 28

CN VII, IX, X Visceral sensory information - taste, baroreceptors, gut distention

Question 29

Which CNs make up the nucleus ambiguus and what is the function?

Answer 29

CN IX, X, XI Motor innervation of pharynx, larynx, upper esophagus - swallowing and palate elevation

Question 30

Which CN makes up the dorsal motor nucleus and what is the function?

Answer 30

CN X Send autonomic (parasympathetic) fibers to heart, lungs, upper GI

Question 31

CN V motor lesion - what are the findings?

Answer 31

Jaw deviates TOWARD lesion, unopposed force from oppostie pterygoid muscle (affected muscle is OPPOSITE lesion)

Question 32

CN X lesion - what are the findings?

Answer 32

Uvula deviates AWAY from lesion, weak side is ipsilateral from lesion, but uvula points away from weak side

Question 33

CN XI lesion - what are the findings?

Answer 33

Weakness turning head to CONTRALATERAL side of lesion (SCM). Shoulder droop IPSILATERAL to lesion (trapezius)

Question 34

CN XII LMN lesion - what are the findings?

Answer 34

Tongue deviates TOWARD side of lesion, weakened muscles on affected side (contralateral to lesion)