Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro Exam 3 > Physiology of the Auditory and Vestibular Systems > Flashcards

Physiology of the Auditory and Vestibular Systems Flashcards

1
Q
  • What are the key features of endolymph?
  • Where is it found?
A
  • K+ rich, Na+ poor
  • Scala media
  • Apical ends of hair cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • What are the key features of perilymph?
  • Where is it found?
A
  • K+ poor, Na+ rich
  • Basal end of cochlear hair cells
  • Scala vestibuli and scala tympani
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  • How does sound travel along the cochlea?
  • What types of sounds does each area detect?
A
  • From base to apex
  • Base=high frequency sounds
  • Apex=low frequency sounds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  • Hair cells are what type of receptor?
    • What is found on the apical side?
    • What is found on the basal side?
A
  • Mechanoreceptors
  • Apical side-stereocilia with kinocillium(king cilia)
  • Basal side has neural synapses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • What type of structural protein is found in stereocilia to make them stiff?
A
  • Actin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  • What creates the large electrochemical gradient for K+ to enter a hair cell following appropriate deflection direction?
A
  • Large endolymphatic potential (K+ concentration gradient)
    • ​Apical end in endolymph with high K+
    • Basal end in perilymph with low K+
  • Large electrical gradient
    • ​Scala media has highly positive charge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  • Deflection towards the kinocilium results in _
  • Deflection away from the kinocilium results in _
    *
A
  • Depolarization
  • Hyperopolarization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  • Deflection of the hair cells towards the kinocilium results in _ and opening of _ channels on the apical surface of the cell, leading to an influx of _
  • This then opens _ channels and leads to the release of _ from the synaptic vesicles (which then diffuses to the postsynaptic afferent neuron)
A
  • Depolarization
  • TRPA1
  • K+
  • Voltage gated Ca2+ channels
  • Glutamate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  • What structure is responsible for maintaining the distinct properties of the endolymph and perilymph?
  • How does it accomplish this?
A
  • Stria vascularis
  • Specialized epithelial cells that pump K+ into the endolymph (they kind of work like the ependymal cells of the blood-csf barrier)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  • On the basilar membrane
    • There is _ row/s of outer hair cells
    • There is _ row/s of inner hair cells
A
  • 3 rows of outer hair cells
  • One row of inner hair cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  • Function of:
    • Outer hair cells
    • Inner hair cells
  • Innervation of
    • Outer hair cells
    • Inner hair cells
A
  • Outer hair cells
    • Innervated by Type II afferents
    • Afferent innervation from spiral ganglia and efferent information from superior olivary complex
    • Function to amplify sound
  • Inner hair cells
    • Innervated by Type I afferents
    • Afferent innervation from spiral ganglia and efferent innervation from superior olivary complex
    • Function as primary source of auditory information
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  • Good summary slide on how uprward bowing of the basilar membrane leads to sound transduction
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  • Function of the DCN
  • Part of what auditory tract (from anatomy lecture)
A
  • Integrates acoustic information with somatosensory information
  • Localization of sound
  • Monaural
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  • Function of the VCN
  • Part of what auditory tract pathway (anatomy lecture)
A
  • Temporal and spectral features of sound (Timing)
  • Binaural pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  • Where is the first site in the brainstem where information in both ears converge?
A
  • Superior olivary complex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  • What is the primary nuclei of the superior olivary complex?
  • Receives _ projections
  • Function of this nucleus
A
  • MSO (Medial superior olivary nucleus) and LSO (Lateral superior olivary nucleus)
  • Excitatory (Glutamate/Aspartate)
  • MSO-interaural time differences (helps with location of sound)
  • LSO-interaural intensity differences (helps with location of sound)

ASIDE:

MSO neuron responds strongest when 2 inputs arrive simultaneously, which occurs when two sides compensate for microsecond differences in the time of arrival of the sound at two ears

The side of a sound localization excites that sides LSO and receives inhibition from contralateral side, but net excitation > net inhibition

17
Q
  • Function of the SC
A
  • Location data from IC and adds vertical height
  • Creates spatial map of sound location
18
Q
  • Function of the IC
A
  • Suppresses information related to echoes
  • Estimates localization of sound along horizontal plane
19
Q
  • Function of MGN of the thalamus
A
  • Relay station in auditory pathway
  • Tonotopic map maintained
  • Lots of convergence from distinct spectral and temporal pathways, allowing for processing features of speech inflections
20
Q
  • A1 function
A
  • Conscious perception of sound
  • Higher order processing of sound
  • Tonotopic map is maintained
  • More rostral areas activated by low frequencies (corresponds to apex of cochlea)
  • More caudal areas activated by high frequencies (corresponds to base of cochlea)
21
Q
  • Auditory (secondary) association cortex functions
A
  • Less tonotopically organized
  • Responds to more complex sounds (music, identifying a sound, speech)
22
Q
  • Summary of various anatomical functons in auditory pathway
A
23
Q
  • Efferent input to the auditory system
A
  • Olivocochlear efferents
  • Middle ear muscle motorneurons
  • Autonomic innervation of the inner ear
24
Q
  • Olivocochlear efferents (OC)
    • Originate in _
    • Medial neurons innervate _
    • Lateral neurons innervate _
A
  • SOC (Superior olivary complex)
  • Medial neurons innervate the outer hair cells
  • Lateral neurons innervate inner hair cells
25
Q
  • Function of olivocochlear efferents
A
  • Shifts responses to higher sound levels
  • Decreases adaptation
  • Reduces response to noise
  • May protect hair cells from damage to intense sounds
26
Q
  • Middle ear efferents
    • ​Where are they located
    • What is their function
A
  • Located in
    • Tensor tympani to malleus (from CN V)
    • Stapedius to stapes (from CN VIII)
  • Function
    • b/l response to high sound levels
    • Contractions decrease transmission of sound
    • Act at low frequencies
    • May prevent damage
    • Prevent low frequency masking (improving speech discrimination)
27
Q

What are the two types of otoacoustic emissions

What is important about them

A
  • Two types
    • Spontaneus (1/3 normal people, usually pure tones produced by motile outer hair cells)
    • Evoked (used to test for hearing loss, no emissions are evoked if damage is present)
  • Clinically important
    • Newborn hearing screen
    • Tinnitus
    • Ototoxicity (drugs can damage stria vascularis and other important structures)
28
Q
  • Sensorineural hearing loss
A
  • Caused by damage to hair cells, nerve fibers, or both
  • Noise damage, ototoxic drugs, age
  • OHCs more susceptible to injury than IHC
  • Base of cochlea more susceptible to damage than apex
  • Injury to outer hair cells causes decrease in sensitivity (higher thresholds) and broader tuning
  • Injury to inner hair cells cuts off auditoru input to CNS
  • Some hearing may be restored with cochlear prosthesis
29
Q
  • Describe angular acceleration and what areas of the vestibular system are responsible for sensing changes in angular acceleration
A
  • Angular acceleration
    • Motion w/ rotation in one or more planes
    • EX: Spinning and turning, falling forwards, falling backwards
  • Semicircular canals
    • ​Anterior -rotation in the vertical plane forwards
    • Posterior-rotation in vertical plane backwards
    • Horizontal-rotation in horizontal plane
30
Q
  • Describe linear acceleration
  • What areas of the brain are responsible for detecting linear acceleration
A
  • Movement in horizontal or vertical plane
    • Moving along a line
    • Horizontally walking
    • Vertically jumping
  • Utricle
    • ​Horizontal/linear acceleration
    • Forward and backward
  • Saccule
    • ​Vertical linear acceleration
    • Up and down
31
Q
  • Vestibule-optic reflex that occurs when you are spinning
A
  • Medial rectus m activated
  • Lateral rectus inhibited (in eye ipsilateral to rotation)
  • Contralateral eye does the opposite
32
Q
  • Vestibule-optic reflex that occurs when you are falling backwards
A
  • Posterior semicircular canal active to backward falling motion
  • Superior oblique activated
  • Inferior oblique inhibited
  • Eyes move down to continue to focus on a point as you fall backwards
33
Q
  • Vestibule-optic reflex that occurs when you are falling forwards
A
  • Anterior semicircular canals are active
  • Superior rectus muscle is activated
  • Inferior rectus muscle is inhibited
  • Eyes move up to keep focus as you fall forwards
34
Q
  • What type of lymph is located in the vestibular apparatus?/What are its features?
  • What type of lymph is located around the vestibular apparatus/what are its features?
A
  • WIthin vestibular apparatus
    • Endolymph (K+ rich)
  • Surrounding vestibular apparatus
    • Perilymph (Na+ rich)
35
Q
  • Function of cortical and cerebellar involvement in the vestibulooptic reflexes
A
  • Suppresses reflex to allow for voluntary motion

Neuro Exam 3 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions