HEARING PT. 2

Question 1

what communicates volume and pitch of sound

Answer 1

frequency of APs being sent tells how loud and
location of activation on basilar membrane tells what pitch

Question 2

where is the cochlear hair located

Answer 2

on top of basilar membrane

Question 3

what do the outer hair cells protect and increase

Answer 3

» Protect inner hair cells from damage
» Increase responsiveness of inner hair cells

Question 4

what do the inner hair cells participate in

Answer 4

sound transduction

Question 5

how do the inner hairs protrude

Answer 5

protrude from top (arranged from longest to shortest)

Question 6

describe tip links of basillalr hairs

Answer 6

inner hair cells are Bound together by tip links, which are connected to mechanically gated ion channels
 Pulling tip links opens ion channels

Question 7

how does sound transduction work

Answer 7

basilar membrane deflected
covers of tip links on hair cell open
hair cells depolarized
send signal to brain

Question 8

how are pitch and volume determined by sound wave itself

Answer 8

pitch determined by frequency of wavelength and volume is determined by amplitude
of waves.

Question 9

how are pitch and volume interpreted in brain

Answer 9

our brain gets pitch info from where basilar membrane was vibrated
and volume info from frequency of action potential to brain

Question 10

why do loud sounds cause damage to eardrum

Answer 10

ouder sound = more deflection of basal membrane

causes damage because deflection can be so great that it rips hair off hair cells

Question 11

how do we localize sounds

Answer 11

depends on relative intensity and relative timing of sound waves reaching both ears

Question 12

whats conduction deafness

Answer 12

when something hampers sound conduction to the fluids of the internal ear
» Impaction of ear wax, perforated eardrum

Question 13

whats sensorineural deafness

Answer 13

results from damage to the neural structures at any point
» Usually gradual loss of hair cells from single very loud noise or prolonged loud noise
» Tears hair off hair cells

Question 14

whats tinnitus

Answer 14

ringing, buzzing, or clicking sound in ears in absence of auditory stimuli » Destruction of some neurons of the auditory pathway

Question 15

whats menrie’s syndrome

Answer 15

labyrinth disorder affecting all of the internal ear » Equilibrium is off, finding balance is hard, vertigo, nausea

Question 16

what are the two regions in the vestibular appartus

Answer 16

vestibule and semicircular canals

Question 17

what does the vestibule contain and what receptors does it house

Answer 17

Contains saccule (extends to cochlea) and utricle (extends to semicircular canals)
Houses equilibrium receptors: respond to gravity pull and head position change

Question 18

what do the semicircular canals contain and what receptors do they house

Answer 18

Contain semicircular duct (communicates with utricle)
House equilibrium receptors in ampulla (swelling): respond to rotational head movement

Question 19

what does the maculae monitor, play a key role in, and respond to

Answer 19

Monitors static equilibrium
» Plays key role in control of posture
» Responds to linear acceleration forces (not rotational)

Question 20

what are the two maculaes called

Answer 20

utricle and saccule

Question 21

what does the utricle maculae respond to and what is it stimulated by

Answer 21

Respond to change along a horizontal plane, such as tilting your head
 Stimulated by forward/backward movements

Question 22

what does the saccule maculae respond to and what it is stimulated by

Answer 22

Respond to changes along a vertical plane
 Stimulated by up/down movements

Question 23

does the maculae have hair cellls

Answer 23

yes, stereo cilia that are embedded in a otolith (stone) membrane

Question 24

what do the hair cells do for membrane

Answer 24

give it weight and increases inertia

Question 25

what happens if the stones fall out of otolith membrane

Answer 25

causes inertia

Question 26

what does the Cristae Ampullares monitor and respond to

Answer 26

Monitors dynamic equilibrium
» Responds to rotational forces

Question 27

how is the crust ampullares activated

Answer 27

Endolymph (inside membrane of the labyrinth) articulates with the Crista receptors
Bends hairs causing depolarization and increases afferent impulses to the brain

BASICALLLY, WHEN YOU ROTATE, HAIRS FLOP IN A CERTAIN DIRECTION