Vestibular

Question 1

Vestibular-Cochlear systems (what brings them together)

Answer 1

Two separate systems housed in thesameend organ, with the sameperipheral innervation

Question 2

Vestibular-Cochlear systems are innervated by what

Answer 2

CN 8 - vestibulocochlear

Question 3

what is the difference between hearing and listening

Answer 3

hearing - accidental, involuntary, effortless

listening - focused, voluntary, intentional

Question 4

where is the Vestibular cochlear systemanatomically

Answer 4

structures of inner ear - the petrous portion of the temporal bone

Question 5

how may membrane does the inner ear have

Answer 5

two
out and inner membrane

Question 6

outer membrane of the inner ear

Answer 6

osseouslabyrinthfilled with perilymphfluid

Question 7

inner membrane of the inner ear

Answer 7

membranous labyrinthfilled with endolymph

Vestibular apparatus

Cochlea

Question 8

what is the overall role of the Vestibular system

Answer 8

‘Sense of self-motion’, kinesthesis

Question 9

vestibular system function

Answer 9

Contributes to our sense of self-motion bydetection of head motion

this info is used tostabilize the eyes for vision

Information about self-motion used for maintenance and recovery of balance (via descendingoutput to spinal cord centers)

Question 10

Vestibular system’s has a an effect on what systems

Answer 10

visual andproprioceptive

Question 11

Vestibular system’s impact on vision

Answer 11

Stabilize gaze for accurate vision

Question 12

Vestibular system’s impact on proprioceptive

Answer 12

Generate limb and neck movements to maintain balance duringvoluntary and externally triggered movements

Expectations/predictions of self-motion related to complexvoluntary actions such as reaching and navigation

Question 13

Neurosensory hair cells have what projecting from their apical surface

Answer 13

cilia
Multiple stereocilia; one kinocilia

Question 14

where is the NT release form in a Neurosensory hair cell

Answer 14

base

Question 15

what causes depolarization in a Neurosensory hair cell

Answer 15

Cilia deflected toward the kinocilia

Depolarize hair cell – increase release ofneurotransmitter, increase firing in afferent

Question 16

what hyperpolorizes a Neurosensory hair cell

Answer 16

Cilia deflected away from the kinocilia

hyperpolarize hair cell – decreased release oftransmitter, decrease firing in afferent

Question 17

firing rate of a Neurosensory hair cell

Answer 17

baseline firing rate (always firing this is just subject to change)

Question 18

what are the otolith organs

Answer 18

Utricle and saccule

membranous sacs within the vestibular apparatus

Question 19

function of the otolith organs

Answer 19

Static equilibrium, theposition of the headinspace with respect to gravity (head tilt)

Linear acceleration

Question 20

Linear accelerationof saccule

Answer 20

Vertical direction = saccule

Question 21

Linear accelerationof utricle

Answer 21

Horizontal direction = utricle

Question 22

what is a macula

Answer 22

found inside each utricle and saccule

hair cells are enclosed in a gelatinous mass topped by calcium carbonate crystals called otoconia

Question 23

what happens to the otoconia when you tilt your head

Answer 23

When you tilt you head the rocks move and reflect the gelatinous mass

This will deflect the cilia towards or away from the kino-cilia - effecting the firing rate

Question 24

how do we get directional sensitivity in the vestibular system

Answer 24

Orientationof thekinocilia

Question 25

What enables sensitivity in all directions 

Answer 25

Position of hair cells about the striola  For any tilt or linear acceleration, some cells depolarize, some hyperpolarize, some no change

Question 26

what information do semicircular canals provide

Answer 26

(three canals) provide information on head turning (angular acceleration)

Question 27

ampulla

Answer 27

is a dilatation located at one end of the semicircular canal

Question 28

Hair cells on the ampulla; project cilia into what?

Answer 28

gelatinous mass called the cupula

Question 29

what is the function of the semicircular canals

Answer 29

angular acceleration, a rate of change

Question 30

what happens to the cilia when we accelerate

Answer 30

cilia deflected toward kinocilia, and hair cell depolarized; firing in afferent increases

Question 31

with deceleration what happens to the cilia

Answer 31

cilia deflected away from kinocilia and hair cell hyperpolarized; firing in afferent reduced

Question 32

with constant velocity what happens to the cilia

Answer 32

no change

Question 33

the Semicircular canals to sends input to

Answer 33

Medial and superior vestibular nuclei, (output of nuclei neurons)

Question 34

Medial and superior vestibular nuclei send input to where

Answer 34

output of nuclei neurons to medial longitudinal fasiculus (MLF)

Question 35

Vestibulo-ocular reflexes aim

Answer 35

aim to keep the visual image stable on the retina stabilize eyes

Question 36

Rotational vestibulo-ocular reflex

Answer 36

with head rotation, eyes move opposite to head (slow phase); quick reset (fast phase)

Question 37

Translational vestibulo-ocular reflex

Answer 37

close objects moving fast, far objects moving slower (train window) otoliths stabilize eyes for far object 

Question 38

Ocular counter-rolling response reflexes

Answer 38

with head tilt, otoliths stabilize eyes to correct for vertical offset When you put your head down you eye will roll upward – automatic response

Question 39

Position-vestibular pause (PVP) 

Answer 39

 Vestibular nucleus neurons neurons are primary for reflex receive regular afferent inputs transmit information about passive head movement

Question 40

Floccular target (FTN) 

Answer 40

Vestibular nucleus neurons neurons important to modulate or calibrate the reflex.  Receive irregular afferent inputs and inputs from flocculus of cerebellum

Question 41

Vestibulospinal reflex's function

Answer 41

aim to integrate vestibular with proprioceptive input for accurate spatial orientation to assure upright

Question 42

Vestibular only (VO) neurons

Answer 42

contribute to vestibulospinal tracts  Less involved with head movement and gaze

Question 43

Cerebellar role in Vestibulo-ocular reflexes

Answer 43

to adapt the reflex; both usual vestibular inputs to cerebellum and special visual error signal from climbing fiber input to Purkinje cell, resets vestibular nuclei neuron to be less sensitive to vestibular input - adapts reflex eye movement. 

Question 44

role of the outer ear

Answer 44

‘catches’ and transfers sound waves

Question 45

loud sound protection

Answer 45

Tensor tympani muscle tightens tympanic membrane for loud sound protection

Question 46

role of the middle ear

Answer 46

sound transformed to vibration Stapedius muscle pulls stapes out of oval window for sound power protection

Question 47

inner ear role

Answer 47

pressure waves Neurosensory unit activated for sound reception and representation in afferent firing pattern to central targets for hearing

Question 48

what is the Organ of Corti

Answer 48

a structure in the cochlea of the inner ear which produces nerve impulses in response to sound vibrations.

Question 49

Organ of Corti location

Answer 49

Located in the cochlea of the inner ear

Question 50

Located in the cochlea of the inner ear

Answer 50

perilympyh