Cranial Nerves

Question 1

What do cranial nerves supply?

Answer 1

Supply somatic and visceral motor and sensory information to the head

CN IX and X supply visceral sensory and motor innervation to neck, chest and abdomen

Question 2

Which two cranial nerves are different to the rest in terms of the strucutres that they innervate?

Answer 2

CN IX and X

Supply visceral sensory and motor innervation to neck, chest and abdomen

Question 3

List the cranial nerves?

Answer 3

Question 4

Which cranial nerves are purely sensory?

Which are purely motor?

Which are mixed?

Answer 4

Sensory: 1, 2, 8

Motor: 3, 4, 6, 11, 12

Mixed/both: 5, 7, 9, 10

Some say money matters but my brother says big boobs matter most

Question 5

What are cranial nerves connected to centrally?

Answer 5

Cranial nerve nuclei

Question 6

Describe the broad organisation of cranial nerve nuclei?

Answer 6

Organised rostrally to caudally

Roughly organised in order of target tissues

Question 7

Which cranial nerve nuclei are located in the brainstem?

Answer 7

Nuclei 3-12

Question 8

How are the cranial nerve nuclei arranged in the brainstem?

Answer 8

6 columns either side of midline

Motor nuclei are located in the 3 columns close to midline

Sensory nuclei are located in the 3 lateral columns

Question 9

Where are the motor nerve nuclei located in the brainstem?

Answer 9

3 columns close to midline

Question 10

What are the three motor columns located in the brainstem?

Answer 10

Medial to lateral:

Somatic

Branchial

Visceral

Question 11

Which cranial nerve nuclei are in the somatic motor column? Where in the brainstem are these nuclei located?

Answer 11

Extra-ocular muscles: CN 3, 4, 6

Tongue muscles: CN 12

Question 12

Which cranial nerve nuclei are located in the branchial motor column? Where in the brainstem are they located?

Answer 12

Muscles of mastication: CN 5 (V3)

Muscles of facial expression: CN 7

Muscles of pharynx and larynx: CN 9, 10

Question 13

What is the nucleus ambiguus? Where is it located?

Answer 13

Mostly a motor nucleus

Lies behind inferior olive in medulla

Contains nuclei of CN IX (stylopharyngeus) and X (levator palati)

Question 14

Which cranial nerve nuclei lie in the visceral efferents motor column? Where in the brainstem are they located?

Answer 14

Motor innervation to smooth muscles: CN 3, 7, 9, 10

Question 15

Where are the sensory nerve nuclei located?

Answer 15

In lateral 3 columns

Question 16

What are the three sensory columns located in the brainstem?

Answer 16

Medial to lateral:

Visceral sensory

Somatic sensory

Special sensory

Question 17

Which cranial nerve nuclei are located in the visceral sensory column? Where in the brainstem are they located?

Answer 17

Taste: CN 7, 9, 10

Autonomic: CN 9, 10

Question 18

What is the Nucelus Solitarius? Describe its arrangement?

Answer 18

Nucelus for visceral sensation

Extends from pons to nucleus gracilis

Rostral: gustatory nucleus

Caudal: visceral sensory division

Question 19

Which cranial nerve nuclei are in the somatic sensory column of the brainstem? Where are they located?

Answer 19

Sensation to face, mucosa of nose and mouth, cranial dura: CN 5

Skin behind ear and lining of EAM: CN 7, 9, 10

Question 20

Which cranial nerve nuclei are located in the special sensory column of the brainstem? Where in the brainstem are they located?

Answer 20

Hearing and equilibrium: CN 8

Question 21

Which cranial nerve nuclei arise from the midbrain? Which from the pons? Which from the medulla?

Answer 21

Rule of fours:

Midbrain: 3, 4

Pons: 5, 6, 7, 8

Medulla: 9, 10, 11, 12

Question 22

Describe the locations of all of the cranial nerve nuclei in the brainstem and spinal cord?

Answer 22

Question 23

Describe the olfactory nerve?

Answer 23

Sense of smell

Exits skull at cribiform plate

Question 24

Describe the optic nerve?

Answer 24

Sight

Exits at optic canal

Formed from axons of ganlion cells in the retina

Question 25

What is the optic nerve formed from?

Answer 25

Axons of ganglion cells in the retina

Question 26

Describe the nerves of ocular motion?

Answer 26

CN 3, 4, 6 CN III innervates 4 CN IV innervates superior oblique CN VI innervates lateral rectus Act in a coordinated fashion to move the eyes Exit skull at SOF

Question 27

Describe the oculomotor nerve?

Answer 27

Motor: Innervates 4 extraocular muscles and elevates eyelid PS: Innervates iris and ciliary muscle Exits skull at SOF

Question 28

Describe the passage of the nerves of ocular motion?

Answer 28

All 3 go through cavernous sinus and SOF 4 and 6 go through common tendinous ring

Question 29

Which nerves exit the skull via the SOF?

Answer 29

3, 4, 6, V1

Question 30

Describe the groups that cranial nerves exit the skull in? Why is this signifcant?

Answer 30

Nerves that exit the skull together will be affected by disease together

Question 31

What does the trigeminal nerve innervate?

Answer 31

Sensory: innervates face and inside mouth Motor: innervates muscles of mastication and tensor tympani

Question 32

Describe the three divisions of the sensory division trigeminal nerve? What does each innervate?

Answer 32

V1: opthalmic V2: maxillary V3: mandibular

Question 33

Which structure does the motor division of the trigeminal nerve travel with?

Answer 33

V3 division of sensory division of trigeminal nerve (In picture, blue=sensory, red=motor)

Question 34

Where do each of the sensory divisions of the trigeminal nerve exit the skull?

Answer 34

V1: SOF V2: foramen rotundum V3: foramen ovale

Question 35

Describe the cranial nerves involved in the corneal blink reflex? What is the reflex a test of?

Answer 35

Sensory: CN 6 Motor: CN 7 (both located in pons) Used as a test of pontine function

Question 36

What does the facial nerve innervate?

Answer 36

Motor: muscles of facial expression, stapedius muscle, part of digastric muscle PS: lacrimal, sublingual and submandibular salivary glands Taste: anterior 2/3 tongue and soft palate Sensory: EAM

Question 37

Describe the course of the facial nerve?

Answer 37

Question 38

Describe the terminal branches of the facial nerve?

Answer 38

Temporal Zygomatic Buccal Mandibular Cervical (Tall Zulus Bear Many Children)

Question 39

Which structure do the terminal branches of the facial nerve pass through? Do they innervate this structure?

Answer 39

Parotid gland Do NOT innervate it

Question 40

Describe the vestibulocochlear nerve?

Answer 40

Responsible for hearing and balance Exits skull via internal acoustic meatus

Question 41

Through which foramen does the facial nerve exit the skull?

Answer 41

Internal acoustic meatus

Question 42

Describe the nuclei of CN VIII in the brainstem?

Answer 42

Dorsal and ventral cochlear nuclei Four vestibular nuclei

Question 43

Describe the glossopharyngeal nerve?

Answer 43

Sensory: posterior 1/3 tongue, pharynx, middle ear and carotid body Taste: posterior 1/3 tongue PS: parotid gland Motor: stylopharyngeus Exits the skull via the jugular foramen

Question 44

Describe the pathway of the glossopharyngeal nerve?

Answer 44

Question 45

What does the vagus nerve innervate?

Answer 45

Motor: soft palate, pharynx, larynx, upper oesophagus, 1 tongue muscle (palatoglossus) PS: pharynx to upper abdomen Sensory: pharyn, larynx, oesophagus Input from baroreceptors and chemoreceptors of aortic arch

Question 46

Where does the vagus nerve exit the skull?

Answer 46

Jugular foramen

Question 47

What are the sensory inputs and motor outputs involved in the gag reflex? What does this reflex test?

Answer 47

Sensory: CN IX to pharynx Motor: CN X to pharynx Test of medullary function

Question 48

Are the motor cranial nerves upper or lower motor neurons?

Answer 48

Lower motor neurons

Question 49

Describe the general symptoms of a lower motor neuron problems in a cranial nerve?

Answer 49

Flaccid paraslysis and atrophy

Question 50

What is unique about the pathway of the spinal accessory nerve?

Answer 50

Nucleus is in spinal cord ENTERS cranium via foramen magnum Then travels with CN X roots and exits via jugular foramen

Question 51

What does the spinal accessory nerve innervate?

Answer 51

Motor input to sternomastoid and upper part of trapezius 'Shrug shoulders and turn head'

Question 52

What happens if CN XI input is lost on one side?

Answer 52

Can't turn head in opposite direction

Question 53

Describe the hypoglossal nerve?

Answer 53

Motor innervation to intrinsic and extrinsic muscles of tongue (except palatoglossus) Exits skull via hypoglossal foramen

Question 54

What happens if CN XII input is lost on one side?

Answer 54

Tongue deviation