Lecture 2: Cranial Nerves Flashcards

1
Q

What is the general tract of CN IV?

A
  1. Exit dorsal surface of midbrain and pierce dura mater at margin of entorium cerebelli
  2. Run in lateral wall of cavernous sinus
  3. Enters orbit via superior orbital fissure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cranial Nerve II

What is this nerve?

What is its CNS origin?

What is its distribution?

A

Optic Nerve

Diencephalon

Retina of eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the general tract of CN X?

A
  1. Emerges from medulla
  2. Exit cranium through jugular foramen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cranial Nerve IV

What is this nerve?

What is its CNS origin?

A

Trochlear Nerve

Midbrain: Pontine (Abducens) Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What presents first if CN III is compressed by an aneurysm?

A

Problems with parasympathetic division

Horner’s syndrome symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the general tract of CN VII?

A
  1. Emerges from the pontine-medullary jxn
  2. Cross posterior cranial fossa to exit skull via internal acoustic meatus
  3. Run in facial canal and exit via stylomastoid foramen
  4. Pass through the parotid gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What opening does the CN V2 exit from?

A

Foramen rotundum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What CN is affected in Bell’s Palsy?

What occurs as a result?

A

CN VII

Inability to use facial muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cranial Nerve I

What is this nerve?

What is its CNS origin?

What is its distribution?

A

Olfactory Nerve

Telencephalon

Olfactory mucosa of nose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens if CN III is damaged?

A
  • Ptosis (upper eleyid droop)
  • Paralysis of eye muscles leading to strabismus
    • eyes are not parallel and deviated properly
  • Diplopia (double vision)
  • Difficulty with focus
    • Dilated pupil

Gaze will be down and out!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the general tract of CN XII?

A
  1. Emerges from the medulla
  2. Exits skull via hypoglossal canal
  3. Travels with cervical plexus
  4. Cross occipital A.
  5. Enter oral cavity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the function of CN V2?

A

Sensory Afferent

Skin of face, lower eyelid, cheek, upper lip, maxillary teeth, mucosa of nose, maxillary sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the divisions of CN V?

A

CN V1: Ophthalmic Branch of the Trigeminal Nerve

CN V2: Maxillary Branch of the Trigeminal Nerve

CN V3: Mandibular Branch of the Trigeminal Nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the function of CN XII?

What happens if this nerve is damaged?

A

Somatic Efferent: Supplies all intrinsic and extrensic muscles of the tongue except Palaoglossus Muscle.

If damaged, can lead to difficulty swallowing and speaking.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Cranial Nerve III

What is this nerve?

What is its CNS origin?

A

Oculomotor Nerve

Midbrain/Mesencephalon: Oculumotor and Edinger Westphal nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cranial Nerve IX

What is this nerve?

What is its CNS origin?

A

Glossopharyngeal Nerve

Medulla

Derivatives of 3rd pharyngeal arch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of CN I?

What happens if this nerve is damaged?

A

Special Sensory: smell/olfaction

If damaged, can cause anosmia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Simply put, where are the 12 cranial nerves located?

Use Rule of 4s

A

Cranial Nerves 1-4 are above the pons

Cranial Nerves 5-8 in the pons

Cranial Nerves 9-12 in the medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of CN VII?

A

Special Visceral Efferent (Branchial Motor)

  • Innervates Stapedius muscle (in ear)
  • Innervates Stylohyoid, Posterior belly of Digastric Muscle
  • Innervates muscles of facial expression

General Visceral Efferent

  • Innervates lacrimal, submandibular, and sublingual glands
  • Innervates mucous membrane of nose
  • Innervates hard and soft palates

General Sensory Afferent

  • Skin of concha of auricle, small patch behind ear
  • Helps CN V3 with acoutsti meatus and external tympanic membrane

Special Sensory Afferent

  • Senses taste from anterior ⅔ of tongue
    • CN V3 does sensation!
  • Senses taste from hard and soft palates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the function of CN VIII?

What happens if this nerve is damaged?

A

Special Sensory:

  • Cochlea: Auditory Information
  • Semicircular Canals: Balance Information

If there is damage, can lead to loss balance, nausea, vomitting, dizziness, and deafness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What direction will the tongue deviate if there is a lesion of the hypoglossal nerve on one side?

A

Towards the lesion

May atrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Cranial Nerve V

What is this nerve?

What is its CNS origin?

A

Trigeminal Nerve

Pons

Derivatives of 1st pharyngeal arch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Cranial Nerve VIII

What is this nerve?

What is its CNS origin?

What is its distribution?

A

Vestibulocochlear Nerve

Pontine Medullary Junction

Internal ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cranial Nerve VII

What is this nerve?

What is its CNS origin?

A

Facial Nerve

Pons

Derivatives of 2nd Pharyngeal Arch

25
Q

What are the four parasympathetic ganglion?

A

Cilliary

Pterygopalatine

Otic

Submandibular

26
Q

What CN is involved in closing the eye?

A

CN VII - Facial N.

27
Q

What is the general tract of CN VI?

A
  1. Emerge from brainstem at pontine-medullary junction
  2. Traverse pontine cistern and pierce dura covering the clivus
  3. Run in cavernous sinus near Internal Carotid A.
  4. Enters orbit via superior orbital fissure
28
Q

What is the tract of the CN V1 division?

A

Trigeminal cave => Cavernous sinus => Superior orbital fissure => orbit

29
Q

What is the general tract of CNII from the brain?

A
  1. Optic nerve fibers arise from ganglion cells in retina
  2. Enters cranium via optic foramen
  3. Nerves unite at optic chiasm
  4. Synapse onto lateral geniculate bodies of thalamus
30
Q

What does the parasympathetic motor function of CN VII?

A

Facial Nerve

-Innervates lacrimal gland of the eye, submandibular and sublingual salivary gland

31
Q

If CN X is damaged, what conditions can occur?

A
  • Larnyx issues: hoarseness or loss of voice
  • Difficulty Swallowing
32
Q

What does the parasympathetic motor function of CN X?

A

Vagus Nerve

-Innervates smooth muscles and glands of heart, lungs, larynx, trachea, and most abdominal organs

33
Q

What does the parasympathetic motor function of CN IX?

A

Glossopharyngeal Nerve

-Innervates parotid salivary gland

34
Q

Where is CN I located?

Where does it synapse onto?

A

Olfactory organ through cribiform plate to synapse onto Olfactory bulb

35
Q

What is the function of CN VI?

What happens if this nerve is damaged?

A

Somatic Motor: Lateral Rectus Muscle (abducts eye)

If damaged, can lead to paralysis of lateral eye movements and diplopia

36
Q

What nucleus do the parasympathetic fibers of CN IX arise from?

A

Inferior Salivatory nucleus

37
Q

What cranial nerves go through the superior orbital fissure?

A

CN III, IV, V1, VI

38
Q

Cranial Nerve VI

What is this nerve?

What is its CNS origin?

A

Abducens Nerve

Pontine Medullary Junction

39
Q

What is the function of CN XI?

What happens if this nerve is damaged?

A

Special Visceral Efferent (Branchial Motor): Supplies SCM and Trapezius muscles

If damaged, can lead to difficulty elevation shoulder or turning head to opposite side

40
Q

Cranial Nerve X

What is this nerve?

What is its CNS origin?

What is its distribution?

A

Vagus Nerve

Medulla/Myelencephalon

Derivatives of the 4th pharyngeal arch

41
Q

What is the function of CN IV?

What happens if this nerve is damaged?

A

Somatic Motor: Innervates Superior Oblique Muscle (depresses, internally rotates, and abducts the eye)

If damaged, can lead to limited downard movement of eye, strabismus, and diplopia

42
Q

What is the function of CN II?

What happens if this nerve is damaged?

A

Special Sensory: vision

If damaged, can cause anopsia (visual defects)

43
Q

What is the sympathetic motor function of CN III?

(What muscles is it innervating?)

A

Somatic Motor Functions

  • Innervates intrinsic eye muscle: Elevates eyelid
    • Levator Palpebrae Superioris Muscle
  • Innervates extrinsic eye muscle: Move eyeball
    • Superior Rectus Muscle
    • Medial Rectus Muscle
    • Inferior Rectus Muscle
    • Inferior Oblique Muscle
44
Q

What is the function of CN X?

A

Special Visceral Efferent (Branchial Motor)

  • Innervates most of the striated muscles of pharynx, tongue, and larnyx

General Visceral Efferent

  • Innervates smooth muscles and glands of pharynx, larynx, thoracic and abdominal viscera

Visceral Sensory Afferent

  • Carries sensation from larynx, pharynx, esophagus, thoracic and abdominal viscera
  • Sensation from stretch receptors and chemoreceptors of aortic arch

General Sensory Afferent

  • Sensation from skin at back of ear and external acoustic meatus
  • Sensation from external surface of tympanic membrane and pharyx
    *
45
Q

What is the general tract of CN XI?

A
  1. Emerges from the spinal cord
  2. Enters cranium through foramen magnum
  3. Exit skull through jugular foramen
46
Q

What is the general tract of CN IX?

A
  1. Emerges from medulla
  2. Exit cranium through jugular foramen
  3. Pass b/w superior and middle pharyngeal constrictors
  4. Enter oral cavity
47
Q

What is the function of CN V1?

A

Sensory Afferent

Sensation to cornea, skin of forehead and scalp, upper eyelid, the bridge to the point of nose, and nasal cavity

48
Q

What is the only nerve that exits on the dorsal surface of the brainstem?

A

Trochlear Nerve (CN IV)

49
Q

What is the function of CN V3?

A

Sensory Afferent

  • Anterior 2/3 of the tongue
  • Skin of mandible, lower lip, mandibular teeth, TMJ joint, part of oral mucosa

Visceral Efferent (Branchial Motor)

  • Innervates muscles of mastiation
  • Innervates mylohyoid, anterior belly of digastric muscle, tensor tympani, and tensor veli palatini
50
Q

Which direction does the uvula deviate if there is a lesion on CN X?

A

Away from the side of the lesion

51
Q

What opening does the CN V3 Mandibular exit from?

A

Foramen Ovale

52
Q

What is the parasympathetic motor function of CN III?

(What muscles is it innervating?)

A

Visceral Motor Functions

  • Innervates sphincter pupillae muscle (constrictor)
  • Contracts cilliary muscle to make muscle more round and relaxed (good with near vision)
53
Q

What is the function of CN IX?

A

Special Visceral Efferent (Branchial Motor)

  • Innervates stylopharyngeus muscle

General Visceral Efferent

  • Innervates otic ganglion: stimulates parotid gland

Visceral Sensory Afferent

  • Carries sensation from carotid body and sinus

General Sensory Afferent

  • Sensation to posterior third of tongue
  • Sensation to skin of external ear and internal surface of tympanic membrane

Special Sensory Afferent

  • Senses taste from posterior third of tongue
54
Q

Cranial Nerve XI

What is this nerve?

What is its CNS origin?

What is its distribution?

A

Spinal Accessory Nerve

Superior Spinal Cord

Superficial layer of neck

55
Q

What nucleus do the parasympathetic fibers of CN VII travel with?

A

Superior salivatory nucleus

56
Q

What is the general tract of CN VIII?

A
  1. Enter skull via interal acoustic meatus
  2. Enter brainstem on pontine-medullary jxn
  3. Vestibular - innervate utricle and saccule; Cochlear innervates cochlea
57
Q

Cranial Nerve XII

What is this nerve?

What is its CNS origin?

What is its distribution?

A

Hypoglossal Nerve

Medulla/Myelencephalon

Muscles of tongue

58
Q

What is the general tract of CN III from the brain?

A
  1. Exits midbrain through dura lateral to diaphragma sellae
  2. Runs in lateral wall of cavernous sinus
  3. Enters through superior orbital fissure into orbit