B7-096 Auditory and Vestibular Structure

Question 1

auditory and vestibular hair cells transduce energy via […] movement

Answer 1

stereociliated

Question 2

describe how stereociliated cells transduce sound

Answer 2

endolymph moves stereociliated toward tallest –> opens K+ channels –> depolarizes membrane –> activates voltage dependent Ca+ –> Ca+ enters cells –>release of neurotransmitter –> action potential –> CN VIII

Question 3

deflection of the hair bundle toward the tall side causes

Answer 3

depolarization

(increased impulse frequency, activation)

Question 4

deflection of the hair bundle toward the short side causes

Answer 4

hyperpolarization

(decreased impulse frequency, inhibition)

Question 5

first step in the transduction of hearing to inner ear

Answer 5

vibration of tympanic membrane

Question 6

[…] transmits sound to the vestibule via the oval window

Answer 6

stapes

Question 7

typically, the middle ear is filled with […]

Answer 7

air

(otitis media will change conduction)

Question 8

order of ossicles

Answer 8

malleus
incus
stapes

Question 9

functions of the ossicles [3]

Answer 9

impedance matching
pressure equalization with ET and nasopharynx
gain control via tensor tympani and stapedius (dampen loud sounds)

Question 10

tensor tympani is innervated by

Answer 10

CN V

Question 11

stapedius is innervated by

Answer 11

CN VII

Question 12

compartment of the middle cochlea

Answer 12

membranous labyrinth

Question 13

the membranous labyrinth is filled with […], and surrounded by […] on either side

Answer 13

endolymph
perilymph

Question 14

as sounds enter the cochlea, what sections does it go through in the Organ of Corti? [3]

Answer 14

scala vestibulae (perilymph)
scala media (endolymph)
scala tympani (perilymph)

Question 15

hair cells closer to the middle of the cochlea

main sensory transducers sending info to CNS

Answer 15

inner hair cells

Question 16

hair cells further from the middle of the cochlea

alter movement of basilar membrane to sharpen tuning properties

Answer 16

outer hair cells

Question 17

[inner/outer hair cell]

lots of afferent fibers

Answer 17

inner

Question 18

[inner/outer hair cell]

efferent fibers

Answer 18

outer

(help control how active they are in moving the basilar membrane)

Question 19

releases energy via round window

Answer 19

scala tympani

Question 20

as the basilar membrane moves, the tops of the hair cells in the cochlea shear along the […] to move one way or another

Answer 20

tectorial membrane

Question 21

cochlea is organized according to

Answer 21

pitch/frequency

Question 22

how does tonotopic organization get set up?

Answer 22

sounds of a specific frequency maximally stimulate movement of a specific part of the basilar membrane

Question 23

high frequency sounds stimulate the […] of cochlea

Answer 23

base

Question 24

low frequency sounds stimulate the […] of cochlea

Answer 24

apex

Question 25

properties of the apex of the cochlea that allow for transmission of low frequency sound

Answer 25

wide and loose

Question 26

properties of the base of the cochlea that allow for transmission of high frequency sound

Answer 26

narrow/tight

Question 27

sharpen and increase "acuity" of sound

Answer 27

outer hair cells

Question 28

because outer hair cells can move the basilar membrane, they can

Answer 28

create sounds that originate in the ear (otoacoustic emissions)

Question 29

all other nuclei above the level of the cochlear nucleus receive input from

Answer 29

both ears (hard to have ipsilateral hearing loss from damage to CNS)

Question 30

[...] hair cells are primarily responsible for sending auditory information to the CNS

Answer 30

inner

Question 31

[...] hair cells modify the movement of the basilar membrane

Answer 31

outer

Question 32

can hair cells regenerate?

Answer 32

no

Question 33

there are 3 rows of [...] hair cells

Answer 33

outer

Question 34

high frequencies at the [...]

Answer 34

base

Question 35

low frequencies at the [...]

Answer 35

apex

Question 36

specific frequencies of sound excite hair cells at a specific location because of the properties of the [...]

Answer 36

basilar membrane

Question 37

differences in [...] along the basilar membrane dictate frequencies at which hair cells respond

Answer 37

stiffness and width

Question 38

fluid movement in the scala vestibuli transmits pressure wave to the [...] which creates movement of the basilar membrane

Answer 38

scala media

Question 39

[...] hair cells change the stiffness of the basilar membrane to sharpen frequency tuning

Answer 39

outer

Question 40

the [...] scrapes across the tops of the stereocilia to activate them

Answer 40

tectorial membrane

Question 41

middle ear ossicles stimulate [...] at the oval window

Answer 41

scala vestbuli

Question 42

movement toward the long stereocilia [...] neurotransmitter release, movement away [...] it

Answer 42

movement toward the long stereocilia increases neurotransmitter release, movement away decreases it

Question 43

structures of the CNS auditory pathway leading to the primary auditory cortex in the temporal lobe [4]

Answer 43

superior olivary nucleus dorsal cochlear nucleus medial geniculate nucleus inferior colliculus

Question 44

the [...] surrounds stereocilia of vestibular hair cells in the semicircular canal

Answer 44

cupula (bends them in direction of endolymph)