Exam 2 CN VIII Flashcards
Is the vestibulocochlear nerve sensory or motor?
It is purely sensory
T/F the vestibulocochlear nerve is made up of two nerves the vestibular nerve and the cochlear nerve
True
Where does the vestibular nerve terminate (non-specific)
In the vestibular nuclear complex
What parts make up the vestibular nuclear complex
Superior, medial, lateral, and inferior
Fibers carried in the vestibular nerve arise from cell bodies located where?
In the vestibular ganglion
What two parts make up the vestibular ganglion
Inferior and superior parts
Where does the cochlear nerve terminate
Terminates in two nuclei; anterior and posterior
What is the cochlear nerve composed of primarily
Composed of axons from spiral ganglion
What is the cochlear nerve made up of
Bipolar neurons
Where are the cell bodies located for the bipolar neurons of the cochlear nerve
Located in the spiral ganglion
What extends from the spiral ganglion to the spiral organ?
Peripheral processes (dendrites)
What is another name for the spiral organ
Organ of Corti
Axons from the cell bodies of the cochlear nerve are carried to where
They are carried to two cochlear nuclei, located in the posterior, superior M.O. , lateral to vestibular nuclei where they terminate
From the cochlear nuclei, axons cross to where and then synapse where?
The other side of the brainstem and synapse in the trapezoid nuclei
After axons from the cochlear nerve synapse in the trapezoid nuclei what do they then form
The axons form the lateral lemniscus
What 3 inner ear structures do the peripheral processes of the vestibular ganglion extend to
The saccule, utricle, and semicircular canals
What convey information to the vestibular nuclei and where are they from?
Central processes from the vestibular ganglion
Where is the vestibular nuclei located?
In the MO on the floor of the rhomboid fossa
Where do most vestibular nerve fibers terminate (specific)
In the medial vestibular nucleus or Schwalbe
Some vestibular fibers travel directly to the cerebellum by way of what
The inferior cerebellar peduncle
What way does information of the vestibulocochlear travel
Distal to proximal
What is the apparent origin of the vestibulocochlear nerve
The cerebellopontine angle
Where does the vestibulocochlear nerve travel within on its way to the internal acoustic meatus
Posterior cranial fossa where it enters along with the facial nerve
How many fibers does the cochlear nerve carry within the temporal bone
30-40,000
How many fibers does the vestibular nerve carry in the temporal bone
About 20,000
As the vestibular nerve travels within the temporal bone what happens as it approaches the ear
It divides into superior and inferior branches
How many fibers makeup the smaller inferior branch of the vestibular nerve
About 8,000
What nerves make up the smaller inferior branch of the vestibular nerve
The saccular nerve and the posterior ampullary nerve
What do the saccule and posterior ampullary nerve supply
The saccule and posterior ampullary nerve crest
How many fibers make up the larger superior branch of the vestibular nerve
About 12,000 fibers
What forms the larger superior branch of the vestibular nerve after it splits and what do they supply
Lateral and ampullar nerves which supply the lateral and anterior semicircular ducts
How is the utricle supplied
By a branch from the lateral ampullary nerve and a branch directly off the superior branch
Where does the superior branch of the vestibular nerve send a branch directly to and what is the name of that nerve
The saccule, named Voit’s nerve
What two branches make up the inferior branch of the vestibular nerve after it splits
The saccular nerve and the posterior ampullary nerve
What is an acoustic neuroma
Vestibular Schwannoma
What is tinnitus
Ringing in the ears
Tinnitus is the first sign of what disease and what are the other symptoms
Mire’s disease which is vertigo, tinnitus, and hearing loss
What is vestibular disease
You experience a lot of vertigo
How do you tell the difference between vestibular disease vertigo and cervicogenic vertigo?
Do the spinning in the chair test. If it reproduces vertigo then it is a good indication it is cervicogenic vertigo
