Midterm III: Facial Nerve, CN VII (Ben) Flashcards Preview

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Flashcards in Midterm III: Facial Nerve, CN VII (Ben) Deck (23):
1

What are the 4 nuclei of the facial nerve (VII) ?

What type is each?

Where are they?

  1. Facial Nerve Nucleus
    • BM + SVM ... lower pons
  2. Superior Salivatory Nucleus
    • GVM ... lower pons
  3. Solitary Tract Nucleus
    • SVS (taste) ... medulla
  4. Spinal Trigeminal Nucleus
    • GSS (protopathic) ... from pons to C1-2

2

What is the brain exit of the CN VII (Facial N.)?

What is the dural exit?

What is the skull exit?

brain - btwn pons + brachium pontisposteriorly

dural - internal acoustic meatus (fundus)

 skull - internal acoustic meatus, facial canal, stylomastoid foramen

3

What is the ganglion within the facial canal?

Many fibers pass through it but only 2 types synapse here.
 

What type and from which nerves?

Geniculate Ganglion

  1. SVS - from chorda tympani (ant 2/3 tongue, taste)
  2. GSS - from posterior auricular branch (protopathic, external ear)

4

What is the first branch of the facial nerve?

What type of nerve is it + what does it innervate?

Where does it arise from?

Greater Petrosal Nerve

- GVM innervating lacrimal gland

- from the geniculate ganglion

(but just from fibers passing through, no synapse there)

5

Describe the course of the greater petrosal nerve from its origin to the organ it innervates.

  1. Exits petrous part of temporal bone via hiatus for greater petrosal nerve
  2. Exits middle cranial fossa via foramen lacerum
  3. Joins with deep petrosal nerve (sympathetic) to form Vidian nerve
  4. Travels through Pterygoid Canal (of Vidius)
  5. Synapses in Pterygopalatine Ganglion (GVM)
  6. Joins Zygomatic Nerve (V/2) through Inferior Orbital Fissure
  7. Joins lacrimal nerve to innervate the lacrimal gland

6

How does the greater petrosal nerve leave the petrous part of the temporal bone?

And then how does it exit the middle cranial fossa of the skull?

temporal bone - via hiatus for greater petrosal nerve

skull - via foramen lacerum

7

What nerve does the greater petrosal nerve join with as it exits the skull?

What nerve does this combination create?

Deep Petrosal Nerve (sympathetic, from int. carotid plexus)

- creates the Vidian Nerve or Nerve of the Pterygoid Canal

8

Where does the Vidian nerve end?

And what kind of neurons are there?

Pterygopalatine Ganglion

multi-polar neurons carrying parasympathetic info

9

How do parasympathetic fibers originating from the greater petrosal nerve eventually enter the orbit?

inferior orbital fissure

10

What are the 4 intra-cranial branches of the facial nerve?

  1. Greater Petrosal N.
  2. Stapedius N.
  3. Chorda Tympani N.
  4. Sensory Auricular Branch

11

What kind of nerve is the stapedial nerve and why?

Branchiomotor

- it innervates the stapedius muscle which is a muscle of the 2nd pharyngeal arch

12

How does the chorda tympani exit the skull?

Petrotympanic Fissure

or

Glaserian Fissure

13

How does the facial nerve exit the skull to give its extra-cranial branches?

via the stylomastoid foramen

14

What are the extra-cranial branches of CN VII?

  1. Posterior Auricular N.
  2. Digastric Branch
  3. Stylohyoid Branch
  4. Parotid Plexus (w/in parotid gland)

15

What are the nerves of the parotid plexus?

(5 nerves/branches in 2 groups)

Temporofacial:

  • Temporal Branches
  • Zygomatic Branches
  • Buccal Branches

Cervicofacial:

  • Marginal Mandibular Branch
  • Cervical Branch

16

Which branch of CN VII innervates the peri-auricular muscles + occipital belly of occipitofrontalis?

Posterior Auricular Nerve

17

What does the digastric branch of the extra-cranial facial nerve innervate?

ONLY the posterior belly of the digastric

18

What is the general visceromotor nucleus of CN VII?

Superior Salivatory Nucleus

19

What is the branchiomotor nucleus of CN VII?

What branchial structures does it innervate?

Facial Nucleus

Muscles of the 2nd Pharyngeal Arch:

  • Mimetic muscles
  • Platysma
  • Stapedius
  • Stylohoid
  • Auricular muscles
  • Digastric, posterior belly

    MPS SAD

20

What is the general visceromotor nucleus of CN VII?

Superior Salivatory Nucleus

- taste innervation to ant. 2/3 tongue via chorda tympani

21

What is the general somatosensory nucleus of CN VII?

Spinal Trigeminal Nucleus

- protopathic sensibility via sensory auricular branch

22

What part of CN VII innervates the platysma?

Cervical Branch

- connecting with Transverse Cervical Nerve to create Superficial Cervical Ansa

23

Fibers from what two types of nuclei make up the intermediate nerve which is associated with CN VII?

And what are the nuclei?

GVM - superior salivatory nucleus

SVS - solitary nucleus

 

(extra: nervus intermedius enters facial canal with facial nerve as the facial trunk)