Final Exam- Unit VIII-- Ears Flashcards Preview

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Flashcards in Final Exam- Unit VIII-- Ears Deck (69)
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1
Q

What does the ear embryologically develop from?

A

ectodermal thickening on later “head” called the placode

2
Q

What is the ectodermal thickening on the lateral “head” that the ear develops from called?

A

placode

3
Q

What will the placode do and what will it give rise to?

A

it invaginates–> gives rise to auditory pit, and then the auditory vesicle

4
Q

What does the Auditory Vesicle give rise to most of?

A

the membranous inner ear

5
Q

What are the auditory tube and tympanic cavity derived from?

A

first pharyngeal pouch

6
Q

What is the malleus derived from?

A

the dorsal end of the ventral mandibular carilage

7
Q

What is the incus derived from?

A

dorsal end of the first pharyngeal arch

8
Q

What is the stapes derived from?

A

dorsal end of the second pharyngeal arch

9
Q

What does the tympanic membrane develop from?

A

interstitial mesoderm

10
Q

What does the external acoustic canal develop from?

A

first pharyngeal groove

11
Q

What does the auricle develop from?

A

a groove next to the first pharyngeal groove

12
Q

What three areas does the ear consists of?

A
  1. external portion
  2. middle portion
  3. inner portion
13
Q

What two things does the external ear include?

A
  1. auricle

2. external acoustic meatus

14
Q

What is another name for auricle? What does it serve to do?

A

pinna

a horn-like structure that serves to funnel sound waves into the external acoustic meatus

15
Q

What is the auricle composed of?

A

cartilage

16
Q

What are the landmarks of the Auricle?

A
  1. helix
  2. antihelix
  3. scaphoid fossa
  4. triangular fossa
  5. concha of the auricle
  6. tragus
  7. antitragus
  8. intertragic notch
  9. lobule
17
Q

What are the three extrinsic muscles that position the auricle? Which is the smallest? Which is the largest?

A
  1. anterior auricular muscle–> smallest
  2. superior auricular muscle–> largest
  3. posterior auricular muscle

(if have “auricular” in name = extrinsic muscle)

18
Q

Is the anterior auricular muscle an extrinsic or intrinsic muscle?

A

extrinsic muscle

19
Q

Is the superior auricular muscle an extrinsic or intrinsic muscle?

A

extrinsic muscle

20
Q

Is the posterior auricular muscle an extrinsic or intrinsic muscle?

A

extrinsic muscle

21
Q

What are the 6 intrinsic muscle of the ear?

A
  1. helicis major
  2. helicis minor
  3. tragicus
  4. antitragicus
  5. transverse muscle of the auricle
  6. oblique muscle of the auricle
22
Q

How long is the external acoustic meatus? What is it shaped like? What is the medial 2/3 within?

A

about 1 inch in length; “S” shaped; medial 2/3 is w/in temporal bone

23
Q

What is the external acoustic meatus covered in? What type of glands does it contain and what do they produce?

A

covered by skin

contains Modified sweat glands that produce cerumen (ear wax) = ceruminous glands

24
Q

Where does the external acoustic meatus terminate?

A

at the tympanic membrane

25
Q

Since the external acoustic canal is not straight (it is shaped like an “S”) how is otoscopic examination made possible?

A

gently pulling out, down, and forward on the lobule

26
Q

What three vessels provide the blood supply to the external ear? What are they branches of?

A
  1. Posterior auricular branch of the external carotid artery
  2. Anterior auricular branch of the superficial temporal artery
  3. Auricular branch from the occipital artery
27
Q

What types of nerve supply does the external ear receive?

A
  1. Sensory
  2. Motor
  3. Sympathetic

(no parasympathetic)

28
Q

What is the sensory nerve supply to the external ear?

A
  1. Auriculotemporal nerve of V3
  2. Auricular branch of vagus
  3. Great auricular nerve (C2 and C3– cervical plexus)
29
Q

What is the motor nerve supply to the external ear?

A

Temporal and Posterior auricular branches of the facial nerve (CN VII) – (from parotid plexus)

30
Q

Where does the external ear receive sympathetic supply from?

A

the superior cervical ganglion

31
Q

What is the small space between the tympanic membrane and the inner ear?

A

Middle ear

32
Q

What two parts does the middle ear consist of?

A
  1. Tympanic cavity

2. epitympanic recess (superior to tympanic cavity)

33
Q

What three small bones are found in the inner ear and can you list them lateral to medial?

A

Malleus, Incus, Stapes

34
Q

What two muscles are located in the tympanic cavity?

A
  1. Stapedius

2. Tensor Tympani

35
Q

What are the 6 boundaries of the middle ear called?

A
  1. Roof or tegmental wall
  2. Floor or jugular wall
  3. Lateral or membranous wall
  4. Posterior or mastoid wall
  5. Carotid wall
  6. Labyrinthine or medial wall
36
Q

What forms the Roof or Tegmental wall of the middle ear?

A

petrous part of the temporal bone

37
Q

What forms the Floor or Jugular wall?

A

a thin layer of bone separating the cavity from the internal jugular vein

38
Q

What opening does the Floor or Jugular wall contain and what is it for?

A

small opening for entrance of the Tympanic Branch of the glossopharyngeal nerve (CN IX)

39
Q

What part of the middle ear contains a small opening for the Tympanic Branch of the glossopharyngeal nerve?

A

the Floor or Jugular wall

40
Q

What forms the Lateral or membranous wall of the middle ear?

A

almost entirely by the tympanic membrane; also a bony part adjacent to the epitympanic recess

41
Q

What wall of the middle ear is incomplete?

A

the Posterior or Mastoid wall

42
Q

What wall of the middle ear contains an opening between the tympanic cavity and the mastoid air cells and what is this opening called?

A

the Posterior or Mastoid wall, called the Aditus of the Mastoid Antrum

43
Q

What openings does the Posterior or Mastoid wall of the middle ear contain?

A

(3)
1. Aditus of the Mastoid Antrum
2. Pyramidal eminence
3. Chorda Tympani entering

44
Q

What is the opening called for the tendon of the stapedius muscle and what wall is it located in in the middle ear?

A

Pyramidal eminence on the Posterior or Mastoid wall

45
Q

What wall of the middle ear contains the opening for the Chorda Tympani where it enters? What about where it exits?

A

enters–> Posterior or Mastoid wall

extis–> Carotid Wall (more ant. wall)

46
Q

What is the Aditus of the Mastoid Antrum an opening between and what wall of the middle ear contains it?

A

b/w tympanic cavity and mastoid air cells on the Posterior or Mastoid wall

47
Q

What does the Carotid wall of the middle ear separate?

A

the tympanic cavity from the internal carotid artery

48
Q

What openings does the Carotid wall contain?

A

3 openings for:

  1. Pharyngotympatic tube
  2. Tensor tympani passes
  3. Chorda tympanic exiting
49
Q

What wall of the middle ear contains the large opening for the Pharyngotympatic tube?

A

Carotid wall

50
Q

What wall of the middle ear separates the tympanic cavity from the internal carotid artery?

A

Carotid wall

51
Q

What wall of the middle ear contains the opening through which the tensor tympani passes?

A

Carotid wall

52
Q

What wall of the middle ear is the boundary b/w the middle ear and the inner ear?

A

Labyrinthine or medial wall

53
Q

What is the Labyrinthine or Medial Wall the boundary b/w? What landmarks are found on this wall?

A

the middle ear and the inner ear

Landmarks:

  1. Promontory
  2. Oval window (where stapes is attached)
  3. Round window
  4. Prominence of the facial canal
  5. Lateral semicircular canal
54
Q

What is the impression made by the cochlea on the Medial/Labyrinthine wall called? What covers this?

A

the Promontory–> covered by Tympanic Plexus

55
Q

What forms the Tympanic Plexus, which covers the promontory on the Medial/Labyrinthine wall?

A

Typmanic branch of CN IX and branches from internal carotid plexus

56
Q

What does the Tympanic plexus supply?

A

mucus membranes of middle ear, mastoid area, and pharyngotympanic tube

57
Q

What nerve travels right through the Tympanic plexus that is traveling to the otic ganglion? What type of fibers is it carrying?

A

lesser petrosal nerve (name change from the Tympanic nerve from CN IX)

travels right through the Tympanic plexus and is carrying preganglionic parasympathetic fibers

58
Q

Where does the stapes articulate with the cochlea?

A

oval window where it attaches on the Medial/Labyrinthine wall

59
Q

What is an impression of bone formed by a canal conducting the facial nerve called and what wall of the middle ear is it on?

A

Prominence of the facial canal on the Medial/Labyrinthine wall

60
Q

What wall of the middle ear do we find the lateral semicircular canal?

A

on the Medial/Labyrinthine wall forming a small impression

61
Q

What three very small bones are located in the tympanic cavity? Which is largest? Which is most lateral?

A
Largest/most lateral   "MIS"
1. Malleus
2. Incus
3. Stapes 
smallest/most medial
62
Q

What is the largest of the three small bones in the tympanic cavity? What is it in contact with?

A

Malleus; in contact with the tympanic membrane

63
Q

What of the three small bones in the tympanic cavity transmits vibration form the malleus to the stapes?

A

incus

64
Q

What of the three small bones in the tympanic cavity has its base sitting against the oval window?

A

stapes

65
Q

What is the blood supply to the middle ear and what are they branches off of?

A
  1. Anterior tympanic branch of the internal maxillary artery

2. Tympanic branch of the internal carotid artery

66
Q

What type of nerve supply goes to the middle ear?

A
  1. Sensory
  2. Motor
  3. Sympathetic

(no parasympathetic)

67
Q

What is the sensory nerve supply to the middle ear?

A

Tympanic Nerve of CN IX

68
Q

What is the motor supply to the middle ear and what muscles do they supply?

A
  1. Nerve to the Stapedius of the Facial Nerve (VII)–> supplying Stapedius muscle
  2. Medial Pterygoid nerve of the mandibular division (V3) –> supplying Tensor Tympani muscle
69
Q

What is the sympathetic nerve supply to the middle ear? What type of fibers does it carry? Where are they fibers from and how did they get there?

A

Caroticotympatnic nerves carrying:

  • vasomotor
  • secretomotor fibers

–> from the superior cervical ganglion via the internal carotid plexus