CN VIII

Question 1

What is the name given to CN VIII?

Answer 1

Vestibulocochlear nerve

Question 2

What kind of information is carried by CN VII?

Answer 2

special sensory only

Question 3

How many nerves make up CN VIII and what are they?

Answer 3

2; vestibular and cochlear

Question 4

Where does the vestibular nerve terminate?

Answer 4

vestibular nuclear complex

Question 5

What are the 4 parts of the vestibular nuclear complex?

Answer 5

superior (bechterew), medial (schwalbe), lateral (deiter), and inferior

Question 6

Which part of the vestibular nuclear complex gives rise to most of the fibers of the vestibulospinal tract?

Answer 6

lateral (deiter)

Question 7

Where do fibers in the vestibular nerve originate?

Answer 7

cell bodies in the vestibular ganglion

Question 8

Where is the vestibular ganglion?

Answer 8

internal acoustic meatus

Question 9

T/F: the vestibular ganglion has 2 parts, inferior and superior.

Answer 9

true

Question 10

Where does the cochlear nerve terminate?

Answer 10

in the two cochlear nuclei (anterior and posterior)

Question 11

Where do the axons composing the cochlear nerve originate?

Answer 11

spinal ganglion

Question 12

What kind of neurons make up the cochlear nerve?

Answer 12

bipolar neurons

Question 13

Where are the cell bodies of the neurons that make up the cochlear nerve?

Answer 13

in the spiral ganglion of the cochlea

Question 14

What is the route of peripheral processes of the cochlear nerve?

Answer 14

from spiral ganglion to spiral organ

Question 15

What is the other name for the spiral organ?

Answer 15

organ of Corti

Question 16

Where are the nuclei of termination for the cochlear nerve (cochlear nuclei) located?

Answer 16

in the posterior, superior MO, lateral to the vestibular nuclei

Question 17

From the cochlear nuclei, axons cross to the other side of the brainstem and synapse in what nuclei?

Answer 17

trapezoid nuclei

Question 18

What do axons from the trapezoid nucleus form?

Answer 18

lateral lemniscus

Question 19

Where do fibers from the lateral lemniscus travel?

Answer 19

to medial geniculate body of thalamus (with a few fibers dropping off in the inferior colliculus)

Question 20

What 3 inner ear structures are innervated by peripheral processes from the vestibular ganglion?

Answer 20

saccule, utricle, and semicircular canals

Question 21

Where are the vestibular nuclei?

Answer 21

in the MO on the floor of the rhomboid fossa

Question 22

Where do central processes from the vestibular ganglion convey info to?

Answer 22

vestibular nuclei

Question 23

Where do most vestibular nerve fibers terminate?

Answer 23

in the medial vestibular nucleus (Schwalbe)

Question 24

How do some fibers of the vestibular nerve travel directly to the cerebellum?

Answer 24

by way of the inferior cerebellar peduncle

Question 25

Which direction does info in CN VIII travel?

Answer 25

from distal to proximal

Question 26

Where is the apparent origin of CN VIII?

Answer 26

cerebellopontine angle

Question 27

T/F: CN VIII has no branches to structures outside of the ear.

Answer 27

True

Question 28

From its apparent origin, what fossa does CN VIII travel in to get to the internal acoustic meatus?

Answer 28

posterior cranial fossa

Question 29

What other cranial nerve enters the internal acoustic meatus along with CN VIII

Answer 29

Facial (VII)

Question 30

T/F: The cochlear nerve carries about 60,000 fibers.

Answer 30

False; 30-40k

Question 31

After traversing the internal acoustic meatus inferior to the facial nerve, the cochlear nerve leaves the temporal bone to reach what structure?

Answer 31

spiral ganglion of the cochlea

Question 32

How many fibers are carried by the vestibular nerve?

Answer 32

about 20k

Question 33

Which branch of the vestibular nerve is bigger, the superior or the inferior branch?

Answer 33

superior branch is bigger

Question 34

What does the inferior branch of the vestibular nerve supply?

Answer 34

saccule and posterior ampullary crest

Question 35

what two nerves compose the inferior branch of the vestibular nerve?

Answer 35

saccular nerve and the posterior ampullary nerve

Question 36

What is supplied by the superior branch of the vestibular nerve?

Answer 36

lateral and anterior semicircular canals

Question 37

What two nerves form the superior branch of the vestibular nerve?

Answer 37

lateral and anterior ampullary nerves

Question 38

What branch(es) supply the utricle?

Answer 38

a branch from the lateral ampullary nerve and a branch directly off the superior branch of the vestibular nerve

Question 39

In addition to the semicircular canals and the utricle, what else is supplied by the superior branch of the vestibular nerve?

Answer 39

saccule

Question 40

What is the name of the branch from the superior branch of the vestibular nerve which innervates the saccule?

Answer 40

Voit's nerve

Question 41

T/F: all of the nerve fibers that innervate the utricle ultimately come from the superior branch of the vestibular nerve.

Answer 41

True

Question 42

What ganglion does the cochlear nerve travel to?

Answer 42

spiral ganglion

Question 43

What ganglion does the vestibular nerve travel to?

Answer 43

vestibular ganglion

Question 44

What clinical consideration of CN VIII can cause hearing problems and perhaps get large enough to increase pressure on the brain stem/cranium?

Answer 44

Acoustic neuroma

Question 45

What is the other name for an acoustic neuroma?

Answer 45

vestibular schwanoma

Question 46

What is tinnitus?

Answer 46

ringing in the ears

Question 47

What disease mentioned in class can tinnitus be the 1st sign of?

Answer 47

Manier's Disease

Question 48

Other than ringing in the ears, what other symptoms are associated with tinnitis?

Answer 48

hearing deficits and vertigo

Question 49

Are cochlear implants more or less common modernly?

Answer 49

more common

Question 50

Patients with severe hearing loss, specifically sensorineural hearing loss with a functioning cochlear nerve, are candidates for what?

Answer 50

cochlear implants

Question 51

Sit a patient in a swivel chair, hold the head stationary, and swivel the chair to identify a cervical spine issue (if this causes vertigo). What is this a test for?

Answer 51

vestibular disease

Question 52

T/F: vestibular disease has a differential diagnosis from cervicogenic vertigo.

Answer 52

true