Midterm III: Cranial Nerves III, IV, VI, IX (Ben) Flashcards Preview

Y Anatomy, Histo, Embryo III > Midterm III: Cranial Nerves III, IV, VI, IX (Ben) > Flashcards

Flashcards in Midterm III: Cranial Nerves III, IV, VI, IX (Ben) Deck (26):

What are CN III's two nuclei?

What type of nuclei are they?

Where are they?


  1. Edinger-Westphal (GVM)
  2. Oculomotor Nucleus (SM)

Both in the midbrain, superior collicle level.


What is the brain exit of CN III?

Dural exit?

Skull exit?

brain - interpeduncular fossa

dural - cavernous sinus wall

skull - superior orbital fissure


What are the 2 branches of the oculomotor nerve?

  1. Superior
    • ​​superior rectus
    • levator palpebrae superioris
  2. Inferior
    • ​​inferior/medial rectus
    • inf. oblique
    • pre-synaptic GVM fibers


Where do CN III's general visceromotor fibers end?

  • GVM fibers end in the Ciliary Ganglion (on multi-polar neurons)


What does the superior branch of CN III supply?

  • levator palpebrae superioris
  • superior rectus


What does the inferior branch of CN III supply?

  • medial rectus
  • inferior rectus
  • inferior oblique
  • presynaptic GVM fibers to ciliary ganglion


What are the postganglionic parasympathetic fibers originating from CN III called?

What do they innervate?

E-W Nucleus fibers synapse in ciliary ganglion and go on to form...

Short Ciliary Nerve

which innervates...

  • Ciliaris Muscle
  • Sphincter Pupillae


What is the nucleus for CN IV?

Where is it?

Trochlear Nucleus 

(SM, crossed)

- in the midbrain, inferior collicle level


What is the brain exit of CN IV?

Dural exit?

Skull exit?

brain - below inferior colliculi

dural - lateral wall cavernous sinus

skull - superior orbital fissure


What muscle is innervated by CN IV?

superior oblique


What is the nucleus of CN VI?

Where is it?

Abducens Nucleus


- in the pons


What is the brain exit of CN VI?

Dural exit?

Skull exit?

brain - ponto-medullary junction, both sides foramen caecum

dural - cavernous sinus (via Dorello's canal)

skull - Superior Orbital Fissure


What muscle does CN VI innervate?

lateral rectus


What are the 5 nuclei of the glossopharyngeal nerve (CN IX)?

What types of nuclei are they?

(Extra: where are they?)

  1. Inferior Salivatory Nucleus - GVM
    • (P-M junction)
  2. Nucleus of Lateral Ala Cinerea - GVS
  3. Solitary Nucleus - SVS
  4. Nucleus Ambiguus - BM
  5. Spinal Trigeminal Tract - GSS

(2-5 in open medulla)




What is the brain exit of CN IX?

Dural exit?

Skull exit?

brain - lateral parolivary sulcus

dural - jugular foramen

skull - jugular foramen


Which branchial arch is the glossopharyngeal nerve associated with?

3rd branchial (pharyngeal) arch


What branchial arch-related muscle does CN IX innervate?



What are the 4 main branches of the glossopharyngeal nerve?

(3 branches + 1 plexus)

  1. Tympanic Nerve (of Jacobson)
  2. Communicating Branch to Auricular Branch of Vagus (Arnold's Nerve)
  3. Carotid Branch (Hering's Nerve)
  4. Pharyngeal Plexus





Where does the tympanic nerve (of Jacobson) start and end?

and how does it get there?

Start - Inferior Ganglion of CN IX, just outside of jugular foramen

...hooks back into skull via Tympanic Canaliculus

End - Tympanic Plexus, within tympanic cavity, giving 3 branches




What 3 branches does the tympanic nerve give after its tympanic plexus within the tympanic cavity?

  1. Lesser Petrosal Nerve
  2. Deep Petrosal Nerve
  3. Tympanic Branches (---> tymp. cavity mucosa)


How do the inferior salivatory nucleus' fibers reach their target?

And what is the target?

GVM fibers from the inf. salivatory nucleus travel...

  1. via CN IX to its inferior ganglion
  2. as tympanic nerve to tympanic plexus
  3. as lesser petrosal nerve to otic ganglion
  4. as postsynaptic parasympathetic fibers to the parotid gland


Where does the carotid branch of CN IX begin?



(in the direction of transmission)

Begin - baro-/chemoreceptors of carotid body

Ganglion - Inferior Ganglion of CN IX (pseudounipolar, not synapse)

End - Lateral Ala Cinerea Nucleus (GVS)


What is the branchiomotor nucleus of CN IX and what does it innervate?

Where do its fibers synapse?


Nucleus Ambiguus

- innervates pharyngeal muscles via pharyngeal plexus

- directly innervates stylopharyngeus via its own branch

- its fibers pass through both sup/inf glossopharyngeal ganglia without synapsing


What is the general somatosensory nucleus of CN IX?

Where do its fibers synapse?

Spinal Trigeminal Nucleus

- synapse in the superior ganglion of CN IX

(just inside the jugular foramen)


What does the spinal trigeminal tract innervate via the glossopharyngeal nerve?

GSS innervation to...

  • Oropharynx
  • Pharyngeal Tonsil
  • Tongue, Post. 1/3
  • Tympanic Cavity




To where does CN IX give taste sensation?

Via what ganglion?

And to what nucleus?

Posterior 1/3 Tongue

- Inferior Ganglion of CN IX

- Solitary Nucleus