chapter 53 - exam 4

Question 1

external ear parts

Answer 1

pinna, EAM, auditory canal

Question 2

external ear function

Answer 2

transmit soundwaves to middle ear

Question 3

middle ear parts

Answer 3

tympanic membrane, ossicles, auditory tube, tensor tympani muscle, stapedius muscle

Question 4

middle ear function

Answer 4

Turn sound waves into vibration. conduct sound waves through air, impendence matching, attenuation reflex, drains into nasopharynx, relieve pressure

Question 5

inner ear parts

Answer 5

bony labyrinth surrounding membranous labyrinth, semicircular canals, utricle, saccule

Question 6

inner ear function

Answer 6

Turns vibration into nerve impulses. transduction of fluid vibrations to nerve impulses

Question 7

what structures do sound waves pass through as they travel to inner ear

Answer 7

EAM, auditory canal, tympanic membrane, malleus, incus, stapes, oval window

Question 8

what is the order of the ossicle bones from external to internal

Answer 8

malleus, incus, stapes

Question 9

what does the stapes contact

Answer 9

oval window

Question 10

what sound wave characteristics determines the volume of the sound

Answer 10

amplitude of the sound wave

Question 11

what does a higher amplitude mean

Answer 11

louder

Question 12

what sound wave characteristics determines the pitch/tone of the sound

Answer 12

frequency of the sound wave

Question 13

what does a higher frequency mean

Answer 13

higher pitch

Question 14

impedance matching

Answer 14

compression of sound waves to help transition from air conduction to fluid conduction

Question 15

what 2 muscles are involved in attenuation of sound

Answer 15

stapedius + tensor tympani

Question 16

what nerves innervate the 2 muscles involved in attenuation of sound

Answer 16

CN VII + CN V3

Question 17

when is attenuation used

Answer 17

for loud sounds + background noise

Question 18

what frequencies are most affected by attenuation

Answer 18

low (background noise)

Question 19

what are the 3 inner tubes of the cochlea

Answer 19

scala vestibuli, scala media, + scala tympani

Question 20

what separates the scala vestibuli from the scala media

Answer 20

vestibular (reissner’s) membrane

Question 21

what separates the scala media from the scala tympani

Answer 21

basilar membrane + organ of corti

Question 22

what is filled within the scala vestibular

Answer 22

perilymph

Question 23

what is filled within the scala media

Answer 23

endolymph

Question 24

what is filled within the scala tympani

Answer 24

perilymph

Question 25

where is the organ corti

Answer 25

Basilar membrane

Question 26

what is the function of the organ of corti

Answer 26

Sensory receptor for hearing. transduce vibration frequency of sound waves in the fluid to a nerve impulse

Question 27

length of basilar fibers at base of ear

Answer 27

shorter + fatter

Question 28

what is the pitch when basilar fibers are short

Answer 28

higher pitch/frequency

Question 29

length of basilar fibers at apex of ear

Answer 29

longer + thinner

Question 30

what is the pitch when basilar fibers are longer

Answer 30

deeper pitch

Question 31

resonant frequency

Answer 31

the basilar fibers that match the vibrational frequency of incoming fluid wave + vibrates with the most ease to cause energy dissipation

Question 32

the place principle

Answer 32

Detection of sound wave frequency (pitch) determined by basilar membrane

Question 33

where along basilar membrane does higher frequency stimulate an action potential

Answer 33

near the base (oval window)

Question 34

where are lower frequency sounds transduced into nerve impulses

Answer 34

the apex (helicotrema)

Question 35

what hair cells are the main receptors

Answer 35

inner hair cells

Question 36

when are outer hair cells activated

Answer 36

only when sound is VERY loud

Question 37

what allows K+ channels to open and flood into ear

Answer 37

stereocilia bent towards base/tallest hairs

Question 38

what triggers the opening of Ca2+ channels in the ear

Answer 38

stereocilia bent towards apex

Question 39

endolymph

Answer 39

made by stria vascularis, similar to ICF. high in k+

Question 40

perilymph

Answer 40

continous with CSF, similar to ECF. high in Na+

Question 41

where is endolymph found

Answer 41

scala media

Question 42

where is perilymph found

Answer 42

scala vestibuli + tympani

Question 43

endocochlear potential

Answer 43

an extra sensitized environment for hair cells to respond to the quietest sound

Question 44

3 responses to high amplitude sound waves

Answer 44

attenuation reflex, temporal summation, spatial summation

Question 45

temporal summation

Answer 45

basilar fibers excite hair cells at a rapid frequency

Question 46

spatial summation

Answer 46

basilar fibers of neighboring frequencies also activated

Question 47

decibel

Answer 47

unit for measuring sound intensity

Question 48

power law

Answer 48

compression of the scale of sound intensity

Question 49

high frequency pitch detected at ___ volume

Answer 49

low

Question 50

low frequency pitch detected at ____ volume

Answer 50

high

Question 51

central auditory pathways

Answer 51

BE ABLE TO DRAW THE PICTURE

Question 52

What type of nerves are cochlear nerves

Answer 52

Bipolar

Question 53

What does an influx of Ca2+ cause in the ear

Answer 53

Glutamate to be released and trigger action potentials

Question 54

Where do cochlear nerve cell bodies reside

Answer 54

Spiral ganglia

Question 55

Where are 2 order neurons for cochlear nerves

Answer 55

Medulla

Question 56

Time lag

Answer 56

Sound enters the closer ear to sound first, then detected by medial superior olivary nucleus