PNS Exam 2

What type of information does vestibulocochlear nerve carry?

sensory

What is the apparent origin of vestibulocochlear nerve?

cerebellopontine recess

Where does vestibulocochlear nerve exit the vault?

internal acoustic meatus

What bone is vestibulocochlear nerve within?

temporal bone

How many fibers does cochlear nerve have?

30-40 K

Where does the cochlear nerve pass through?

passes through internal acoustic meatus below facial nerve

Where do fibers reach after passing though internal acoustic meatus and exiting temporal bone?

spiral ganglion in cochlea

How many fibers does the vestibular nerve contribute?

20K

What are the two branches the vestibular nerve divides into after leaving vestibular ganglion?

superior and inferior branch

How many fibers does the superior branch of vestibular nerve contribute?

12K

How many fibers does the inferior branch of vestibular nerve contribute?

8K

What branches come off of the superior branch of vestibular nerve? What do they supply?

1. Anterior ampullary→ anterior semi-circular duct

2. Lateral ampullary→ lateral semi-circular duct

3. 2 branches to utricle

4. Voit’s nerve→ saccule

Where are the two branches that supply the utricle?

1. Comes off lateral ampullary

2. Comes directly off superior branch

Where is voit’s nerve located?

directly off superior branch of vestibular nerve

supplies saccule

Where are the two nerves that supply the saccule?

1. Voit’s nerve→ off superior branch

2. Sacular nerve→ off inferior branch

What are the two branches that come off the inferior branch of vestibular nerve?

1. Sacular nerve

2. Posterior ampullary nerve

What are the two names for tumors of CN VIII?

Acoustic neuroma

Vestibular schanoma

(can’t balance and can’t hear)

What is tinnitus?

ringing in ears

What is the 1st symptom of meinere’s?

tinnitus

Cochlear implants are only effective for what?

sensory neural hearing loss

How do you differentiate between vestibular disease and cervicogenic vertigo?

Vestibular disease→ push the chair

Cervicogenic vertigo→ swivel the chair

What are the nuclei of termination for vestibular nerve?

1. Superior/Bechtaren

2. Medial/Schwalbe

3. Lateral/ Dieter

4. Inferior

What nuclei of termination is associated with vestibulospinal tract?

lateral/dieter

Where is the vestibular ganglion located?

internal acoustic meatus

Where are the cell bodies of vestibular nerve located?

vestibular ganglion

Where do vestibular nerve fibers terminate?

vestibular nuclei →majority in medial nucleus

Where do dendrites of vestibular nerve extend to?

1. Saccule

2. Utricle

3. Semi-circular ducts

Some vestibular nerve fibers go directly into__ via _

vestibulocerebellum

inferior cerebellar peduncle

What is the nuclei of termination for cochlear nerve?

cochlear nuclei→ anterior and posterior

What ganglion does the cochlear nerve use?

spiral ganglion inside the cochlea

In the cochlear nerve, cell bodies of first order sensory neurons are in _

spiral ganglion

Where do dendrites go to in the cochlear nerve?

spiral organ

Cochlear nuclei axons cross over and synapse where?

1. Trapezoid body

2. Superior olivary nucleus

What do axons from trapezoid body and superior olivary nucleus form?

lateral lemniscus→ synapses in cerebrum

What type of information does glossopharyngeal nerve carry?

mixed

motor→ stylopharyngeus

sensory→ general, special, visceral

autonomic→ parasympathetic

What is the nucleus of origin for glossopharyngeal nerve?

nucleus ambiguus

Nucleus ambiguus has LMN from what CN?

9,10,11

What is the parasympathetic nucleus for glossopharyngeal nerve?

inferior salivary nucleus

What are the nuclei of termination for glossopharyngeal nerve?

1. Spinal nucleus of trigeminal → pain and temperature

2. Solitary nucleus→ taste (superior) and visceral sensory (inferior)

What are the two peripheral ganglia for glossopharyngeal nerve?

1. Superior ganglion of CN 9→ inside skull

2. Inferior ganglion of CN 9→ outside skull

ANS fibers synapse in otic ganglion

Where is general sensory information from in glossopharyngeal?

1. nasopharynx

2. oropharynx

3. posterior tongue

4. uvula

5. palatine tonsils

6. tympanic cavity→ ear infections

Where are general sensory cell bodies located for glossopharyngeal?

inferior ganglion

What is the nucleus of termination for general sensory information of glossopharyngeal?

spinal nucleus of trigeminal

Where does taste information come from for glossopharyngeal?

lingual branch→ posterior 1/3 of tongue

Where are cell bodies of taste fibers located for glossopharyngeal?

inferior ganglion

What is the nucleus of termination for taste fibers of glossopharyngeal?

superior part of solitary nucleus

Where does visceral sensory information come from in glossopharyngeal?

carotid branch→ carotid body and carotid sinus

What is the cell body location and nucleus of termination for visceral afferent information of glossopharyngeal?

inferior ganglion

inferior part of solitary nucleus

What muscle does the glossopharyngeal nerve supply?

stylopharyngeus

What is the parasympathetic pathway for the glossopharyngeal nerve?

preganglionic fibers from inferior salivary go to otic ganglion

postganglionic fibers from otic ganglion go to parotid gland, buccal gland, and inferior labial gland

What is the apparent origin of glossopharyngeal nerve?

lateral aspect of superior medulla oblongata

Where does the glossopharyngeal nerve exit the skull?

jugular foramen

What is the tympanic nerve?

given off inferior ganglion

1. preganglionic parasympathetic info to otic ganglion

2. somatosensory info to tympanic cavity

3. postganglionic sympathetic fibers from superior cervical ganglion

Tympanic nerve enters tympanic cavity via __

tympanic canaliculus

The preganglionic parasympathetic fibers and postganglionic sympathetic fibers from tympanic nerve form ___ __

tympanic plexus

Where does tympanic plexus send somatosensory information?

1. Tympanic cavity

2. Pharyngotympanic tube

3. Mastoid air cells

Preganglionic parasympathetic fibers travel through tympanic plexus and form ___

lesser petrosal nerve

Where do fibers that travel through tympanic plexus and form lesser petrosal nerve synapse?

otic ganglion

What do postganglionic parasympathetic fibers from otic ganglion supply?

1. Parotid gland

2. Buccal gland

3. Inferior labial gland

What are the branches of glossopharyngeal?

1. Muscular→ stylopharyngeus

2. Carotid branch→ carotid body and carotid sinus

3. Pharyngeal branch → pharyngeal mucosa

   Terminal branches

4. Tonsillar branch → palatine tonsils and oral mucosa

5. Lingual branch→ taste from posterior 1/3 of tongue

Pharyngeal branch of glossopharyngeal nerve combines wiith CN __ to form _ __

CN X

pharyngeal plexus

What damaged nerve could cause loss of taste?

Glossopharyngeal

test using bitter and sour

What is a good test for glossopharyngeal nerve?

gag reflex

What is the longest and most important parasympathetic nerve?

Vagus nerve

What type of information does vagus carry?

mixed

What is the nuclei of origin for vagus?

nucleus ambiguus→ recieves info from both cerebral hemispheres

What is the parasympathetic nucleus for vagus nerve?

posterior nucleus of vagus→ information indirectly from carotid sinus and hypothalamus

What are the nuclei of termination for vagus nerve?

1. spinal nucleus of trigeminal

2. solitary nucleus

What are the peripheral ganglia of CN X?

1. Superior (jugular) ganglion→ neurons synapse in spinal nucleus

2. Inferior (nodose) ganglion→ neurons synapse in solitary nucleus

What is the general sensory pathway of CN X?

info from infratentorial dura

cell bodies in superior ganglion

nuclei of termination→ spinal nucleus

What is the taste pathway of vagus nerve?

info from epiglottis

cell bodies in inferior ganglion

nuclei of termination→ superior part of solitary nucleus

What is the visceral pathway of vagus?

info from larynx, thoracic and abdominal viscera, baroreceptors, and chemoreceptors

cell bodies in inferior ganglion

nuclei of termination→ inferior part of solitary nucleus

What is the apparent origin of vagus nerve?

lateral aspect of medulla oblongata

Where does vagus exit the skull?

jugular foramen

How is the jugular foramen compartmentalized?

CN 9→ travels posterior to septum

CN 10-11→ travel anterior to septum

What branch of vagus is given off before exiting jugular foramen?

meningeal branch

What does the meningeal branch supply?

infratentorial dura

What is the auricular branch of vagus?

given off in superior ganglion

supplies EAM and auricle

The auricular branch of CN 10 travels through ___ and ____ to external acoustic meatus

mastoid canaliculus

tympanomastoid fissure

Once vagus exits jugular foramen, where to next?

inside carotid sheath between internal carotid and internal jugular

inferior to carotid bifurcation→ between common carotid and internal jugular

What are the contents of carotid sheath with vagus?

1. internal jugular

2. internal common carotid

vagus branches given off the neck are found where?

between jugular foramen and thorax

The pharyngeal branch of vagus contributes to pharyngeal plexus along with __

1. Pharyngeal branch of Glossopharyngeal nerve

2. Sympathetic fibers

What is the motor supply of the pharyngeal branches/plexus?

1. pharyngeal constrictors

2. levator veli palatini

For laryngeal innervation, which way does the uvula deviate?

deviates towards good side

What are the branches to carotid artery of vagus ?

given off at inferior ganglion

carry viscerosensory fibers→ chemoreceptors in carotid body

synapse in inferior pat of solitary nucleus

What is the superior laryngeal nerve of vagus?

comes off inferior to inferior ganglion

1. External laryngeal nerve→ cricothyroid

2. Internal laryngeal nerve→ laryngeal mucosa up to vocal fold

   synapse in spinal nucleus of trigeminal

What is the recurrent laryngeal nerve of vagus?

motor to all muscles of larynx except cricothyroid

sensory info from larynx inferior to vocal folds

left recurrent laryngeal nerve comes off vagus after vagus passes anterior to ___ ___

aortic arch

Right recurrent laryngeal comes off vagus after vagus passes anterior to ___ ___

subclavian artery

What contributes to cardiac plexus of vagus?

1. superior cardiac branches→ from vagus

2. inferior cardiac branches→ from recurrent laryngeal

In thoracic cavity, nerve pass ___

posterior to root of lung

L/R vagus nerves enter __ __

esophageal hiatus

Is the left vagus anterior or posterior to esophagus?

anterior to esophagus

The left vagus forms the __

anterior vagal trunk

supplies, stomach, liver, pancreas, superior part of duodenum

The R vagus forms the ___

posterior vagal trunk

supplies posterior stomach

What is the terminal branch of posterior vagal trunk?

celiac branch

What branch suppplies the rest of duodenum, jejunum, ileum, liver, kidneys, and proximal 2/3 of large intestine?

celiac branch

Organs are supplied via plexuses:

1. Celiac plexus

2. superior mesenteric plexus

3. Renal plexus

What nerve is bilateral transaction associated with? (Associated with death)

vagus