Midterm III: CNs X-XII (Ben) Flashcards Preview

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Flashcards in Midterm III: CNs X-XII (Ben) Deck (25):

What 5 nuclei are associated with the vagus nerve (CN X)?

What kind fibers does each contribute to CN X?

  1. Ambiguus - BM, SVM
  2. Dorsal Vagal - GVM
  3. Solitary - SVS
  4. Lateral Ala Cinerea - GVS
  5. Spinal Trigeminal - GSS


What is the brain exit of CN X?

Dural exit?

Skull exit?

brain - lateral parolivary sulcus

dural - jugular foramen

skull - jugular foramen


Where do the vagus nerve's general visceromotor (parasympathetic) fibers originate?

And end?

Dorsal Vagal Nucleus (GVM)

End in:

  • Meissner's/Auerbach's Plexuses - intramural ganglia of GI tract
  • Prevertebral Ganglia - for thoracic organs


Where do CN X's branchiomotor (AKA special visceromotor) fibers originate?

Where do they synapse (generally)?

Nucleus Ambiguus

- synapse directly on target muscles... no ganglion


Where do CN X's general somatosensory fibers originate?

Where is their ganglion/cell body?

On what nucleus do they end?


Origin - Outer ear + Posterior Dura

Ganglion - Superior (Jugular) Ganglion of CN X

Termination - Spinal Trigeminal Tract


Where do CN X's special viscerosensory fibers originate?

What is their ganglion/cell body?

On what nucleus do they end?

Origin - Epiglottis Taste Buds

Ganglion - Inferior (Nodose) Ganglion of CN X

End - Solitary Nucleus


On what nucleus do CN X's general viscerosensory fibers terminate?

What is their ganglion/cell body?



Lateral Ala Cinerea

Inferior (Nodose) Ganglion of CN X


What organs receive general viscerosensory innervation from CN X?

  • Lower Pharyngeal Mucosa
  • Laryngeal Mucosa
  • Baro-/Chemoreceptors of Aorta + Carotid
  • Thoracic + Abdominal Viscera


What are the 2 sensory ganglia of the vagus nerve near its exit from the skull?

What fiber types have their perikarya in these ganglia?

  1. Superior (Jugular) Ganglion
    • ​​​​GSS fibers
    • protopathic from posterior dura + external ear to spinal trigeminal nucleus
  2. Inferior (Nodose) Ganglion
    • ​​SVS + GVS fibers
    • taste to solitary nucleus
    • visceral sensation to lateral ala cinerea


What 2 branches does the vagus nerve give off to innervate structures of the head?

  1. Meningeal Branch - posterior dura
  2. Auricular Branch - external acoustic meatus + parts of pinna (joined by CN VII + IX)


What 4 sets of branches does the vagus give off in the neck?

  1. Pharyngeal Branches​​
  2. Superior Laryngeal Nerve
  3. Recurrent Laryngeal Nerve
  4. Cardiac Branches
    • ​​Superior + Inferior Cervical Cardiac Branches


What do the pharyngeal branches of the vagus innervate?

  • Sensory - lower pharynx + epiglottis
  • Taste - epiglottis
  • Motor - soft palate + pharyngeal muscles


What specific muscles are innervated by pharyngeal branches of the vagus?

(maybe not so important for midterm III, but for semi-final)

  • Lower 1/2 Middle Pharyngeal Constrictors
  • Inferior Pharyngeal Constrictors
  • Palatopharyngeus
  • Salpingopharyngeus
  • Palatoglossus
  • Levator Veli Palatini




What are the 2 branches of the superior laryngeal nerve (and their innervated organs)?

  1. Internal Laryngeal Nerve
    • mucus membrane of larynx above vocal folds
  2. External Laryngeal Nerve
    • cricothyroid muscle


What are the 3 branches of the recurrent laryngeal nerve?

(What do they innervate?)

  1. Esophageal Branches
  2. Tracheal Branches
  3. Inferior Laryngeal Nerve
    • mucosa of larynx below vocal fold
    • all laryngeal muscles except cricothyroid


What are the 3 important sets of thoracic branches of the vagus?

  1. Thoracic Cardiac Branches
  2. Esophageal Branches
  3. Pulmonary Branches


How do the positions of the vagal nerves change as they descend along the "rotated" stomach?

Anterior Vagal Trunk - comes from left vagus

Posterior Vagal Trunk - comes from right vagus


What are the important 4 abdominal branches/groups of nerves coming from the vagal trunks?

  1. Gastric Branches
  2. Celiac Branches - celiac plexus
  3. Hepatic/Pyloric/Gall Bladder Branches - hepatic plexus in lesser omentum
  4. Nerves for Small and Large Intestines - up to left colic flexure


What are the 2 nuclei associated with the accessory nerve?

What type of nuclei are they?

  1. Nucleus Ambiguus - BM
  2. Spinal Accessory Nucleus - SM


Where is the spinal accessory nucleus of the accessory nerve?

in the lateral anterior horn of the spinal cord from C1-C5


What are the two roots of the accessory nerve?

Where do they unite?

Where do they separate?

  1. Cranial Root
  2. Spinal Root

- unite in the posterior cranial fossa

- separate upon entering the jugular foramen



What does the spinal root of the accessory nerve innervate?

  1. Sternocleidomastoid
  2. Trapezius


What does the cranial root of the accessory nerve innervate?

Via joining the vagus nerve...

  1. All laryngeal muscles except cricothyroid
  2. Pharyngeal muscles


What is the nucleus of CN XII?

What type of nucleus is it?

Where is it?

Hypoglossal Nucleus

- somatomotor

- in the hypoglossal trigone of the medulla


What does the hypoglossal nerve innervate?

Two things it innervates are supplied by a special nerve structure to which CN XII contributes.

What is this structure?

  • Intrinsic Muscles of the Tongue
  • Extrinsic Muscles of the Tongue (except palatoglossus)
  • Geniohyoid + Thyrohyoid
    • via deep cervical ansa