Vestibulocochlear nerve

Question 1

Vestibulocochlear nerve type of nerve and what does it consist of

Answer 1

• sensory afferent nerve innervating receptor cells of membranous labyrinth
• central connections are:
• vestibular nerve: organ of balance
• cochlear nerve: organ of hearing

Question 2

nuclei of the Vestibulocochlear nerve

Answer 2

• cochlear nuclei (2 on each side dorsal and ventral)
• vestibular nuclei (4 on each side)
• medial
• lateral
• inferior
• ventral

Question 3

function and location of the cochlear nuclei

Answer 3

• dorsal and ventral to inferior cerebellar peduncle at level junction of pons with medulla
• special somatosensory

Question 4

function and location of the vestibular nuclei

Answer 4

• in grey matter underlying the lateral part of the 4th ventricle + ponto medullary junction
• special somatosensory

Question 5

brain exit of Vestibulocochlear nerve

Answer 5

between pons and brachium pontis, posterior in the cerebello - pontine angle

Question 6

sub arachnoidal course of Vestibulocochlear nerve

Answer 6

lateral pontine cistern

Question 7

dura penetration of Vestibulocochlear nerve

Answer 7

fundus of the internal acoustic meatus

Question 8

skull exit of Vestibulocochlear nerve

Answer 8

fundus of the internal acoustic meatus

Question 9

ganglia of Vestibulocochlear nerve

Answer 9

• spiral (cochlear ganglia of corti)

- vestibular ganglion of scarpa

Question 10

spiral (cochlear) ganglion of corti

Answer 10

elongated ggl of bipolar sensory nerve cell bodies on the cochlear part of the vestibulocochlear nerve in the spiral canal of modiolus

• each ggl cell gives rise to peripheral process that passes between layers of the bony spiral lamina to the organ of corti
• central axon that enters hindbrain as a component of the inferior root of Vestibulocochlear nerve conveying auditory sensation

Question 11

vestibular ggl of scarpa

Answer 11

• bipolar sensory nerve cell bodies concerned with equilibration and forming a swelling on vestibular part of Vestibulocochlear nerve in the fundus of internal acoustic meatus
• consists of a superior and inferior part connectus by a narrow isthmus

Question 12

cochlear nerve

Answer 12

• composed of central nerve processes of bipolar neurons of the spiral ggl
• > spiral ggl ->spiral tract->cochlear nerve->cochlear nerve root of Vestibulocochlear nerve
• have their peripheral process on the four rows of neuroepithelial cell / hair cells of the spiral organ of corti

Question 13

where do the fibers of the cochlear root project and terminate into

Answer 13

dorsal and ventral cochlear nuclei

Question 14

from ventral nucleus

Answer 14

fibers cross to opposite side to the superior olivary nucleus and after partial synapse in the trapezoid nuclei they ascend as the lateral lemniscus

Question 15

from the dorsal medial nucleus

Answer 15

fibers cross partly as the medullary stria bellow rhomboid fossa -> superior olivary nucleus -> ascends in the lateral lemniscus as well

Question 16

vestibular nerve

Answer 16

part of Vestibulocochlear nerve peripheral to the vestibular root

• composted of central process of bipolar neurons that have their terminals of their peripheral process on the hair cells in the ampullae of the semicircular duckts and the maculae of the saccule and utricle, cell bodies of the vestibular ggl
• central processes unite to give vestibular nerve and root which terminates after bifurcation in the 4 vestibular nuclei of the medulla oblongata and a small portion reaches the cerebellum via the inferior cerebellar peduncle to the flocculonodule lobe