hearing and balance

Question 1

what connects the vestibular system to the cortex and what is its function

Answer 1

meidal lemniscus through thalamus
conscious awareness of position and movements of head

Question 2

what are the rows of hair cells in the organ of corti

Answer 2

includes three rows of outer hair cells and one row of inner hair cells.

Question 3

what is the function of the superior olivary nucleus

Answer 3

This nucleus is the site of origin of olivary cochlear fibres which leave the brain stem in the vestibulocochlear nerve and end in the organ of corti.

Question 4

where are the vestibular nuclei

Answer 4

pons and medulla

Question 5

where do utricle nerve fibres terminate

Answer 5

lateral vestibular nucleus

Question 6

describe the path of the ventral cranial nerve of the cochlear nerve

Answer 6

superior olivary nucleus to lateral lemniscus which runs through the pontine tegmentum to end in the inferior colliculus of the midbrain.

The inferior colliculus in turn sends axons to the medial geniculate nucleus of the thalamus.
Axons that originate in the medial geniculate nucleus and pass through the internal capsule to the primary auditory cortex of the temporal lobe
(SLIM -Superior olivary nucleus, Lateral lemniscus, inferior colliculus, Medial geniculate nucleus)

Question 7

where do saccule nerve fibres terminate

Answer 7

lateral and inferior vestibular nucleus

Question 8

where do vestibular nerve fibres bifurcate

Answer 8

in the vestibular nuclear cortex

Question 9

where do cochlear nuclei second order neurons ascend

Answer 9

into the pons, some of them crossing to the other side of the pontine tegmentum as the trapezoid body.

Question 10

what creates vestibular nerve action potenials

Answer 10

endolymph passing the crista ampularis which contains hair cells

Question 11

what is the nerve supply of the hair cells in the inner ear

Answer 11

the peripheral process of bipolar spiral ganglion cells

Question 12

what is the function of the crista

Answer 12

organ that senses movements of endolymph in the ampulla
senses rotaion and rotational acceleration

Question 13

what are the spiral ganglion

Answer 13

the cell bodies of the cochlear nerve fibres which lie within the cochlea

Question 14

what is the receptor for sound in the organ of corti

Answer 14

is the neuroepithelial cell

Question 15

what is the function of the utriculosaccule duct

Answer 15

gives rise to the endolymphatic duct

Question 16

where do semicircular canal nerve fibres terminate

Answer 16

superior vestibular nucleus and medial vestibular nucleus

Question 17

what connects the vestibular system to the spinal cord and what is its function

Answer 17

vestibulospinal tract
to control posture in balance

Question 18

describe the path of the cochlear nerve

Answer 18

1. The cochlear nerve fibres make dendritic contact with hair cells of the organ of corti within the cochlear duct
2. Its fibres bifurcate and end in the dorsal and ventral cochlear nuclei which lie close to the inferior cerebellar peduncle.

Question 19

where do the vestibular and cochlear nerves attach to the brainstem

Answer 19

at the junction of the medulla and pons in the cerebellopontine angle.

Question 20

what connects the vestibular system to the CN nuclei in brainstem and what is its function

Answer 20

medial longitundinal fisciculus to abducens, trochlear and oculomotor nerve
visual fixation

Question 21

what connects the vestibular system to the cerebellum and what is its function

Answer 21

the vestibulocerebellar pathway
maintaining equilibrium

Question 22

fibres connected at the base of the cochlea will respond best to ______

Answer 22

high frequency sound

Question 23

what is in the static labyrinth

Answer 23

utricle and saccule

Question 24

where does the vestibular nuclei enter the brain stem

Answer 24

at the junction of the medulla and pons

Question 25

what is the membranous labyrinth

Answer 25

a group of ducts (cochlear and semicircular ducts) and chambers (utricle and saccule) filled with endolymphatic fluid.

Question 26

what neural pathways are associated with the vestibular system

Answer 26

those that respond to afferent input from the peripheral vestibular system in the inner ear and provide efferent signals that make these reflexes possible. 

Question 27

where is the primary auditory coretx

Answer 27

in Heschl’s gyri which are situated on the dorsal surface of the superior temporal gyrus

Question 28

what is the function of hair cells in organ of corti

Answer 28

Vibrations caused by sound waves bend the stereocilia on these hair cells via an electromechanical force. The hair cells convert mechanical energy into electrical energy that is transmitted to the central nervous system via the cochlear nerve

Question 29

what is the auditory association cortex

Answer 29

The region of the temporal lobes surrounding the primary auditory cortex and contains the Wernicke’s area.

Question 30

fibres connected at the apex of the cochlea will respond best to ______

Answer 30

low frequency sounds

Question 31

what is a clinical perspective for vestibular nerve

Answer 31

vestibular neuronitis

Question 32

what is the function of the auditory association cortex

Answer 32

is concerned with the memory and classification of sound

Question 33

what is in the kinetic labyrinth

Answer 33

semicircular canals

Question 34

what is the function of the macula

Answer 34

specialised otolyth organs that respond to gravity -head tilting The macula of the saccule detects linear acceleration in the vertical/sagittal plane (up and down). The macula of the utricle detects linear acceleration in the horizontal plane

Question 35

what is the function of the vestibular system

Answer 35

sense of proprioception and equilibrium

Question 36

what parts of the ear are controlled by the vestibular system

Answer 36

semicircular canals utricle and saccule