exam one (audio & vestibular)

Question 1

passage of sound

Answer 1

auditory receptors in cochlea, brain stem neurons, MGN, auditory cortex

Question 2

audible variations in air pressure

Answer 2

sound

Question 3

what is the audible range in humans

Answer 3

20-20,000 Hz

Question 4

perception of sound frequency (low pitch = low frequency, high pitch = higher frequency)

Answer 4

pitch

Question 5

higher intensity is perceived as _____ than low intensity

Answer 5

louder

Question 6

a high amplitude is a ___ sound and low amplitude is ___ sound

Answer 6

loud, soft

Question 7

by age 65 ___ of hair cells are gone

Answer 7

40%

Question 8

sound waves move through the ear in what order

Answer 8

sound waves, tympanic membrane, ossicles, oval window, cochlear fluid, and sensory neuron response

Question 9

what is the function of the ossicles and what are they called

Answer 9

sound amplification by putting pressure on oval window; malleus, incus, stapes

Question 10

reflexive response where onset of loud sound causes two middle ear muscles to contract (these rigid muscles diminish amplification of ossicles)

Answer 10

attenuation reflex

Question 11

fluid in outer tubes of cochlea (scala vestibuli and scala tympani), ion concentrations?

Answer 11

perilymph; low K+ and high Na+

Question 12

fluid in inner ear tube of cochlea (scala media); ion concentration?

Answer 12

endolymph; high K+ and low Na+

Question 13

response of the ____ ____ to sound establishes a place code in different locations of membrane are maximally deformed by different sound frequencies

Answer 13

basilar membrane

Question 14

higher frequencies ____ faster; low frequencies make it further along the basilar membrane

Answer 14

dissipate

Question 15

on the basilar membrane, there are stereocilia extending into tectorial membrane (because basilar membrane moves)

Answer 15

outer hair cells

Question 16

just below the tectorial membrane the __ ____ ___ have stereocilia extending into the endolymph

Answer 16

inner hair cells

Question 17

bending of the basilar membrane moves hair cells relative to ___ ____ bending the ____

Answer 17

tectorial membrane, stereocilia

Question 18

sound bends the basilar membrane upward which results in the stereocilia bending _____; this is the final step of the mechanical message

Answer 18

outward

Question 19

there are more outer or inner hair cells

Answer 19

outer

Question 26

once the mechanically gated channels are open the K+ ions move in which ____ the hair cell membrane

Answer 26

depolarize

Question 27

the bending of the basilar membrane opens mechanicaly gated ___ channels

Answer 27

K+

Question 28

Once the hair cell membrane is depolarized ____ has an influx and GLU is released onto ___ ___ ___

Answer 28

Ca2+ , spiral ganglion cells

Question 29

one spiral ganglion cell then synapses with ____ ____ hair cells but it synapses with only one ____ hair cell

Answer 29

numerous outer; inner

Question 30

one inner hair cells synaposes with only one spiral ganglion cell, true or false?

Answer 30

false

Question 31

sound amplification done the outer hair cells is known as ____ ___

Answer 31

cochlear amplifier

Question 32

outer hair cells have a motor protein called ___ which allows the hair cell to compress and expand; it is driven by acetylcholine neurons (brain stem)

Answer 32

prestin

Question 33

prestin essentially helps the outer hair cell to exaggerate the bending of the ___ ___

Answer 33

basilar membrane

Question 34

without prestin the "wave" will go the same distance down basilar membrane but loses its ___ ___

Answer 34

loud frequency

Question 35

electrode placement of cochlear implants serves to

Answer 35

reserve tonotopic map

Question 36

each cochlear nucleus receives input from ___ ear (medulla)

Answer 36

one

Question 37

neurons are first present in the ___ ___ (medulla)

Answer 37

superior olive

Question 38

what is the pathway after the spiral ganglion cells from the inner ear

Answer 38

auditory nerve takes it to the cochlear nucleus to the superior olive

Question 39

from the medulla where does sound travel as an action potential

Answer 39

it is taken by the lateral lemniscus to the inferior colliculus (mid brain)

Question 40

the superior olive is ____

Answer 40

binaural (sound sharing)

Question 41

from the inferior colliculus sound goes to what structure in the thalamus

Answer 41

MGN to the auditory cortex

Question 42

everything after the medulla (superior olive) is information from both ears, true or false

Answer 42

true

Question 43

encoding sound intensity (loudness) can be done by the ___ ___ of individual neurons

Answer 43

firing rate

Question 44

as intensity increases so does amplitude of basilar membrane movement, this causes the membrane potential to more rapidly become _____ and ______

Answer 44

depolarized and hyperpolarized

Question 45

the membrane becoming hypoerpolarized and depolarized rapidly increases number of action potentials by the ___ ____ ___

Answer 45

spiral ganglion cells

Question 46

another approach encoding loudness is to look at the total number of ____ ____; the more hair cells activated by larger area of basilar membrane vibrating, the broader the frequency range (to which spiral ganglion cells still respond)

Answer 46

active neurons

Question 47

frequency at which neuron is most responsiveness

Answer 47

characteristic frequency

Question 48

firing of auditory nerved correspond to a particular ____ of the sounds wave, which is called phase locking

Answer 48

phase

Question 49

the pinna allows us to have ____ sound localization

Answer 49

vertical

Question 50

interaural time delay (time taken for a sound to reach second ear) is most effective localization strategy for ____ frequency

Answer 50

low

Question 51

interaural intensity difference (head casts a sound shadow, reducing sound intensity) is the most effective localization strategy for ____ frequency sounds

Answer 51

high

Question 52

the impulses of sound reach olivary neuron at the same time and ____ to produce an action potential that indicated perception of sound

Answer 52

summate

Question 53

axons leaving the MGN project to A1 of the primary auditory cortex where organization called ____ is maintained by Hz

Answer 53

tonotopy

Question 54

if there was a uniltateral lesion of the A1 compared to V1 what would happen and why?

Answer 54

The ability to hear would be mostly unaffected (except precise localization) because cross talk happens sooner and both ears get the same stimuli

Question 55

what are the otolith organs and what do they do

Answer 55

utricle and saccule; movement (acceleration and tilt of head)

Question 56

the semicircular canals function to maintain

Answer 56

position

Question 57

hair cells of the otolith organs are embedded in the _____ (sensory epithelium)

Answer 57

macula

Question 58

the cilia which project out of the epithelium are capped by ____ crystals

Answer 58

otoconia

Question 59

the macula hairs respond to ___ ___ through the bending of the cillia

Answer 59

head tilt

Question 60

what benefit is there to have three semicircular canals

Answer 60

they are three different directions and sense all possible head-rotation angles

Question 61

head rotation causes _____ of hair cells in semicircular canal on one side and ____ of hair cells on the other side, this is called?

Answer 61

excitation, inhibition and push-pull arrangement

Question 62

the auditory/vestibular nerve goes from the cochlea to the ____ then the limb and neck motor neurons

Answer 62

medulla

Question 63

reflex that keeps line of sight fixed on visual target when head is in motion

Answer 63

the vestibulo-ocular reflex

Question 64

how does the vestibulo-ocular reflex work

Answer 64

senses rotation of head and rapidly commands movement of eyes in opposite direction