HEARING

1
THE AUDITORY SYSTEM

• HEARING EQUILIBRIUM

2
????????????? (Auditory system)

• ??????????? 2 ???
• ??????????????????????????????????(auditory
  periphery)
• stimulate --gt mechanoreceptor --gt auditory n.
• ??????????????????????????????????(central
  auditory mechanism)

3
?????????????????????????

• 1. ????????? (external ear)
• 2. ?????????? (middle ear or tympanum)
• 3. ???????? (inner ear labyrinth)
• 4. ?????????? cochlear (vestibulocochlear nerve,
  N. VIII)
• 5. ?????????????????????????????????????????(audit
  ory pathway in central nervous system)

4
???????????????????????? (Functional Anatomy of
Ear)

• ???????? 3 ????
• ????????? (External or Outer ear)
• ?????????? (Middle ear)
• ???????? (inner ear)

5
????????? (External or Outer ear)

• ???? -??????????????????????
• ??????????? (tempanic mem. or eardrum)
• ????????????? ??????????????????????????????????
  (car wax) ???????????????????
• ??????????????????????????????????????????????????
  ?? (air conduction)

6
?????????? (Middle ear)

• ?????????????????????????
• ????????? nasopharynx ??? eustachian tube ??
  valve ???, ???? ????????????????
• ???????????????? 3 ???? (earossicles) ??????
  malleus (????), incus (????) ??? stapes (????)
• ?????????????????????????????????????? (air-borne
  sound) ??????????????????? (fluid-borne sound)

7
???????? (inner ear)

• ??????????????????????????????????????????? 2 ???
• auditory apparatus
• cochlea (??????)
• vestibular apparatus
• semicircular canals, utricle???saccule
  (???????????????????????????)

8
Cochlea (????????)

• ???????????????? 35 ??.
• ??????????????? 2 2/4 ???
• ?? 3????
• ??????? 1 scala vestibuli (??????)
  ??????????????????? oval window
• ?????????????? perilymph
• ??????? 2 scala media (????????)??????????????
  endolymph

9
Cochlea (????????)

• ??????? 3 scala tympani (????????)
• ??????????????????? round window
• ?????????????? perilymph
• Reissners membrane ??? ???????????
  ?????????????????? 1 ??? 2
• Basilar membrane ??????????? ??????? 1 ??? 2
  ??????? organ of Corti

10
Organ of Corti

• ?? auditory receptor ??? ???????(hair cells)
  ??????????????
• inner hair cells 3,500 cells ?????
• outer hair cells 20,000 cells ??????
• tectorial membrane ????????????? ???????????????
• ???????????????????????? hair cell
• ????????????????? (sound transduction)
  ?????????????????? (nerve impulse)

11
???????????????????????????

• ?????????????? ?????????????????????-????????????
  ?????
• ??????????????????? Malleus, incus ??? stapes

12
???????????????

• 1. ?????? 3 ????????????????????
• ????????????????????? oval window ????????? 1.8
  ??????????????????????????????????????????
• 2. ?????????????????? (55 ??.2) gt ?????????? oval
  window (32 ??.2) 17 ????
• ??????? (???/??????????) ??????????????? stapes
• ????????? oval window gt ear drum 22 ????
• ???????? ossicular conduction

13
?????????????????????????

• oval window ????????????????????
• ????????? scala vestibuli ??????? ??? round
  window ???????
• ????????? scala vestibuli ???????????????????????
  ?????
• ????????????????????

14
?????????????????????????

• ?????
• high pitched sound ?? peak ????? ???
• low pitched sound ?? peak ????? ???
• ?????Peak ????????????????????????????????
• scala vestibuli (????????????) ---gt???scala
  media ---gt ??? basilar membrane

15
Basilar Membrane

• ??????????????????????? cochlea(???????????????
  ????? ?????????????????????????????)
• ?????????????????????? (??????????????? ?????
  ?????????????????????????????)

16
???????????

• air conduction
• bone conduction

17
???????????

• Air conduction ??????? ?????????????????????????
  -gt organ of corti
• Bone conduction ??????????????????????????????????
  ? -gt endolymph ???? -gt organ of corti
• air conduction ???????????????????? bone
  conduction ????? ??????????????? 17-22 ????

18
?????? (Deafness)

• ???????? 2 ?????????? ?
• Conduction deafness
• Nerve deafness

19
Conduction Deafness

• ??????????????????????????????????????????????????
  ???

• ??????
• ???????????? auditory canal ??? ear wax ????
  ????????????
• auditory ossicles ????????
• ???????????? ear drum

• ?????
• ??????????????
• ???????????????????????????? ????????????????
• -gt cochlea

20
Nerve deafness

• ?????????????? auditory neural pathway

• ??????
• ??????????????????????????????????????
  streptomycin, ?????????????? ??????????????????

• ?????
• ?????? ????????????? ??????????????????????

21
????????????? (Neural pathway)

• spiral ganglion --gt auditory division ???
  acoustic nerve --gt medulla oblongata (cochlea
  nuclei) --gt geniculate body ?? thalamus --gt
  cerebral cortex
• cerebral cortex ?? 2 ??????
• 1o auditory cortex ?????? Brodmanns area ??? 41
  (???????????????)
• auditory association cortex ?????? Brodmanns
  area ??? 42 (?????)

22
Vestibular Apparatus

• ?????????
• ??????????????????????, ????
• ?????????????????????????????

23
Vestibular Apparatus

• ??????????
• ????????? (utricle)
• ?????? (saccule)
• ???????????????? (semicircular canal)

24
semicircular canal

• ?????????? 3 ????????????????
• ?? (superior)
• ???? (posterior)
• ??? (horizontal)
• ?????????????????????????????????? ???????
  (ampulla)

25
??????? (ampulla)

• ????????????????? crista ampullaris
• ??????????
• hair cell
• cilia ???????? (stercocilia) ???cilia ????????
  (kinocilium) ??????? hair cell
• cupula (?????????????)

26
?????????? Crista Ampullaris

• ?????????????????????????????
• endolymph ????????????
• cupula ???????
• hair cell ???
• depolarization (????--gt kinocilium)
• hyperpolarization (???????--gt stercocilia)

27
Crista Ampullaris

• ???????????????????????
• ??? kinocilium ???????????????????????????
• ????????

28
Utricle ??? Saccule

• ???????? semicircular canal
• ?????????????? ????????? (macula)

29
Macula

• ????????? Gelatinous Layer
• Otoconia (?????????????????????)
• ?? Hair Cell ???
• ?? Cilia ??????? Hair Cell
• ???? Hair Cell ??????????????????? ???
• Sensory Axon
• Vestibular Nerve

30
?????????? Macula

• ????????????????????
• hair cell ?????
• ??????? ?????????????????????????????????????????

31
????????????? (Neural pathway)

• impulse --gt vestibular n. (??? cochlea n. --gt CN
  8) --gt auditory n. --gt vestibular nuclei (brain
  stem) --gt cerebellum

?????????