Audition

Question 1

Transduction of sound in the ear happens

Answer 1

mechanically

Question 2

Steps in transduction of sound: 1. sound waves vibrate the

Answer 2

tympanic membrane

Question 3

Steps in transduction of sound: 2. vibrating of the tympanic membrane moves

Answer 3

ossicle bones

Question 4

Steps in transduction of sound: 3. stapes transfers force to the perilymph in the

Answer 4

scala vestibule via the oval window

Question 5

Steps in transduction of sound: 4. fluid in scala vestibule

Answer 5

vibrates

Question 6

Steps in transduction of sound: 5. vibrating fluid causes basilar membrane to vibrate

Answer 6

net result is displacement of basilar membrane relative to tectorial membrane

Question 7

Steps in transduction of sound: 6. displacement causes bending back and forth of stereocilia of hair cells in organ of Corti

Answer 7

when bent one direction they depolarize when bent the other direction they hyperpolarize

Question 8

Steps in transduction of sound: 7. when depolarized the hair cells release

Answer 8

neurotransmitter on spiral ganglion cells

Question 9

Steps in transduction of sound: 8. spiral ganglion cells conduct action potentials in cranial nerve

Answer 9

VIII in response to neurotransmitters

Question 10

Steps in transduction of sound: 9. sound waves are converted into trains of action potentials by

Answer 10

organ of Corti

Question 11

perilymph is like

Answer 11

CSF, it’s extracellular fluid

has high Na+ and low K+ concentrations

Question 12

perilymph fills the

Answer 12

scala vestibule and scala tympani in the cochlea

Question 13

in the bony labyrinth perilymph fills the space between the

Answer 13

bone tissue and the outer surface of the membranous labyrinth

Question 14

endolymph is special

Answer 14

only found in the auditory and vestibular systems

has high K+ concentrations and pretty much no Na+

Question 15

endolymph is present in side the

Answer 15

inner membranes of the membranous labyrinth

Question 16

endolymph is in the

Answer 16

scala media/cochlear duct in the auditory system

Question 17

frequency and amplitude coding in the cochlea

Answer 17

basilar membrane increases its width along its length

Question 18

base of basilar membrane responds to

Answer 18

high frequencies

in humans we can hear up to 20,000 Hz

Question 19

apex of the basilar membrane responds to

Answer 19

low frequencies

in humans we can hear down to 100 Hz

Question 20

at a given frequency there is maximum displacement at some point of the basilar membrane; at that width the

Answer 20

spiral ganglion cells at the location send the maximum number of action potentials into the CNS

Question 21

the region of the basilar membrane with the maximum vibration determines the frequency of the perceived sound

Answer 21

this is know as tonotopic

Question 22

greater number of action potentials from the region determines the

Answer 22

loudness