Auditory System

Question 1

2 functions of auditory system?

Answer 1

hearing, balance

Question 2

3 parts of middle ear?

Answer 2

malleus, incus, stapes

Question 3

function of stapedius mucle?

Answer 3

prevents excess movement of stapes, controls amplitude of sound waves that arrive to middle ear

Question 4

4 parts of inner ear?

Answer 4

vestibule, cochlea, semicircular canals, utricle and saccule (otolith organs)

Question 5

function of vestibule?

Answer 5

contains vestibular window which stapes vibrates against

Question 6

function of cochlea?

Answer 6

transduction of sound, contains organ of Corti

Question 7

function of malleus?

Answer 7

attaches to internal surface of tympanic membrane

Question 8

function of incus?

Answer 8

connects malleus to stapes

Question 9

function of stapes?

Answer 9

attaches to vestibular window (oval/cochlear)

Question 10

function of semicircular canals?

Answer 10

sense rotation of head

Question 11

function of utricle and saccule?

Answer 11

sensitivity to gravity and linear movements of head

Question 12

function of hair cells in semicircular canals?

Answer 12

respond to angular acceleration

Question 13

function of hair cells in cochlea?

Answer 13

sensitive to sound waves travelling through endolymph

Question 14

function of hair cells in otolith organs?

Answer 14

sensitivity to linear acceleration

Question 15

function of mechanoreceptors?

Answer 15

transforms mechanical stimulus of hair cells into sensory potential

Question 16

function of inner hair cells of cochlea?

Answer 16

primary sensory input, activates 8th nerve

Question 17

function of outer hair cells of cochlea?

Answer 17

inc. amplitude and clarity of sound

Question 18

how is pitch determined?

Answer 18

by where a sound wave maximally activates membrane of cochlea

Question 19

how does sound travel to brain from ear?

Answer 19

8th nerve afferent fibers->cochlea -> inferior coliculi (midbrain) -> thalamus -> temporal lobe

Question 20

function of vestibular apparatus?

Answer 20

detects head motion

Question 21

vestibular nuclei function?

Answer 21

maintains body position in space

Question 22

8th nerve function?

Answer 22

supplies semicircular canals & maculae synapse with neuron in vestibular nuclei and cerebellum

Question 23

cerebellum and cortex function?

Answer 23

provide control over sensory integration and motor process

Question 24

what effect does head rotation have on hair cells?

Answer 24

activates hair cells in semicircular canal

Question 25

what’s nystagmus?

Answer 25

characteristic eye movement at the beginning & end of head rotation

Question 26

what does utricular macula respond to?

Answer 26

horizontal acceleration

Question 27

what does saccular macula respond to?

Answer 27

vertical acceleration

Question 28

function of nystagmus?

Answer 28

maintains visual fixation by moving eyes in opposite direction of rotation

Question 29

how do mechanoreceptors work?

Answer 29

mechanically sensitive K ion channels open and let K into cell when short hair leans on long hair -> depolorization -> Glu release -> activates cochlea nerve

Question 30

what do hair cells in otolith organs contain?

Answer 30

crystals of CaCO3 (calcium carbonate)

Question 31

what are hair cells bathed in?

Answer 31

endolymph (high in K)

Question 32

what’s organ of Corti?

Answer 32

receptor organ of hearing located in cochlea