Module 22 - Special Senses: Hearing and Balance

Question 1

define sound

Answer 1

sound – the interpretation
of vibrations

Question 2

define volume

Answer 2

Volume – wave amplitude

Question 3

define pitch

Answer 3

Pitch – wave frequency

Question 4

what collects sound in the external ear

Answer 4

auricle

Question 5

what is the anatomical word for ear drum

Answer 5

tympanic membrane

Question 6

what are the 3 components of the auditory ossicles of the middle ear

Answer 6

malleus, incus, stapes

Question 7

what are the two components of the inner ear that separate the middle and inner ear

Answer 7

oval and round windows

Question 8

what connects the hear to the throat

Answer 8

auditory tube

Question 9

what are the 3 main parts of the inner ear

Answer 9

cochlea - hearing
vestibule - static balance
semicircular canals - dynamic balance

Question 10

the endolymph has more what? Na or K

Answer 10

more K, less Na

Question 11

the perilymph has more what? Na or K

Answer 11

more Na, less K

Question 12

what’s on the outside of the inner ear, the bony labyrinth or the membranous labyrinth

Answer 12

bony labyrinth is on the outside

Question 13

what is the end of the tube in inner ear called

Answer 13

helicotrema

Question 14

where are the hair cells in the cochlea

Answer 14

in the spiral organ

Question 15

what is attached to the round window in the cochlea

Answer 15

scala tympani

Question 16

what is attached to the oval window in the cochlea

Answer 16

scala vestibuli

Question 17

where are the specialized cells in the cochlea

Answer 17

in the basilar membrane

Question 18

what makes up the spiral organ in the cochlear duct

Answer 18

supporting cells, outer hair cells, inner hair cells

Question 19

what is stereocilia

Answer 19

Hair cells have bundles of microvilli at their
apex called stereocilia

Question 20

what is tip-link

Answer 20

tip-link – connects tip of each stereocilium in a hair bundle to the side of the next longer stereocilium

Question 21

Explain depolarization of inner ear

Answer 21

1. Unstimulated – gating
   spring relaxed
2. Stereocilia bend toward
   taller stereocilia – gating
   spring stretches
3. K+ enters the cell

Question 22

lower pitch goes through blank while higher goes through blank

Answer 22

helicotrema, oval window

Question 23

describe the effect of sound waves on the cochlear structures

Answer 23

1. Sound waves enter external auditory canal and strike the tympanic
   membrane causing it to vibrate
2. Vibration is transferred to the middle ear
3. Foot plate of the stapes vibrates in the oval window
4. Vibration of the foot plate causes the perilymph in the scala vestibuli to
   vibrate.
5. Vibration of the perilymph causes the vestibular membrane to vibrate 
   vibrations in the endolymph  displacement of the basilar membrane 
   Movement of the basilar membrane is detected in the hair cells.
6. Vibrations from the perilymph in the scala vestibuli and vibrations in the
   basilar membrane are transferred to the perilymph of the scala tympani.
7. Vibrations in the perilymph of the scala tympani are transferred to the
   round window

Question 24

whats the neural pathway of hearing

Answer 24

Question 25

the utricle deals with blank motion while the saccule deals with blank motion

Answer 25

horizontal, vertical

Question 26

explain static equilibrium

Answer 26

Question 27

the blank dictates head direction in dynamic equilibrium

Answer 27

cupula

Question 28

the cupula moves with or against direction of head?

Answer 28

opposite direction

Question 29

stimulation in dynamic equilibrium stops when…

Answer 29

stimulation stops when fluid in canals catches up with
the cupula

Question 30

what happens when the movement of the head stops in dynamic equilibrium

Answer 30

movement of the head ceases – endolymph continues
to move in the same direction as the head was – cupula
will also

Question 31

explain neural pathway of balance

Answer 31