chapter 12: the ear

Question 1

ear is involved in ___ and ___

Answer 1

hearing and balance ( equilibrium)

both mechanoreceptors

Question 2

2 parts of outer ear & descriptions

Answer 2

1. Pinna: outer flap: acts as a sound funnel, directing it to the auditory canal
2. Auditory canal: canal carrying sound waves to eardrum
   - has specialized sweat glands that produce ear wax to trap invading particles

Question 3

4 parts of middle ear

Answer 3

1. tympatic membrane ( ear drum)
2. ossicles
3. oval window
   4, eustachian tube

Question 4

tympatic membrane

Answer 4

ear drum (in middle ear)

Question 5

ossicles

Answer 5

(middle ear)
aplifies/ passes sound waves from ear drum to oval window by 3 small bones:
1. malleus (hammer)
2. incus (anvil)
3. stapes (stirrup)

Question 6

oval window is..

Answer 6

smaller than eardrum & amplifies sound

Question 7

eustachian tube

Answer 7

air filled tube that equalizes pressure between internal and external ear. also drains excessive fluid to nasal cavity

Question 8

vestibule

Answer 8

(inner ear)
connected to middle ear by oval window, houses 2 small sacs (utricle and saccule) which are involved in head balance ( static equilibrium)

Question 9

semicircular canals

Answer 9

(inner ear)

- 3 fluid filled canals help body balance (dynamic equilibrium)

Question 10

cochlea

Answer 10

(inner ear)
- coiled snail shell, lined with hair cells that respond to different sound waves & frequencies convert them to nerve impule

Question 11

auditory nerve

Answer 11

inner ear

- transmits signal to CNS

Question 12

organ of corti

Answer 12

primary sound receptor in cochlea. composed of 1 inner row and 3 outer rows of hair cells

• basilar membrane
• tectorial membrane
• stereocilia

Question 13

basilar membrane

Answer 13

in organ or corti
- anchors receptor hair cells to the organ or corti. fluid vibrations move the basilar membrane and hair cells bend, which stimulates the sensory nerves that send the auditory signal to the brain (temporal lobe)

Question 14

tectorial membrane

Answer 14

non- mobile top layer (of organ of corti)

Question 15

stereocilia

Answer 15

differ in width and lengths for pitch and volume reception

in organ of corti

Question 16

conductive hearing loss caused by…

Answer 16

was build up, middle ear infection, or punctured ear drum

Question 17

sensorineural hearing loss

Answer 17

auditory nerve severed, or cochlear hair cells damaged

Question 18

balance (rotational equilibrium) maintained by…

Answer 18

the 3 fluid filled semicircular canals

• in each canal, a pocket (ampulla) contains cilia that moves with the gel-like cupula (pulled by forces)
• movement causes the fluid to bend the cilia, initiating a nerve impulse which is carried to the CNS

Question 19

body movement = ____ equilibrium

Answer 19

rotational

Question 20

head position = ____ equilibrium

Answer 20

gravitational

Question 21

gravitational equilibrium maintained by..

Answer 21

2 fluid sacs in vestibule (saccule and utricle)

- in each sac: hair like receptors suspended in a jelly-like material that contains tiny stones called otoliths \

Question 22

what happens when the head bends?

Answer 22

gravity pulls otoliths and gelanous material causing hairs to bend, which stimulate sensory receptors to send messages to the brain

Question 23

otoliths

Answer 23

calcium carbonate granules (tiny stones)

- inside of the saccule and utricle ( 2 fluid filled sacs in vestibule)

Question 24

cochlea

Answer 24

contains the organ or corti

- converts sound waves to electrochemical impulse

Question 25

auditory nerve transmits info (balance and sound) to where in the brain?

Answer 25

balance: cerebellum & parietal lobe
sound: temporal lobe