Anatomy of the Inner Ear Flashcards

1
Q

What imaging modality is the best for assessing disease in middle ear?

A

CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 parts of the ear?

A

External, Middle, Inner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What’s the function of the external ear?

A

Collects sound waves at the eardrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What’s the function of the middle ear?

A

Air filled space where vibrations of tympanic membrane are transmitted by 3 ossicles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What’s the function of the inner ear?

A

Membranous filled sac containing receptor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What type of slices are required for imaging of the ear? And what 2 planes are used?

A

Thin

Axial & coronal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The petrous bone is positioned in an _____ orientation from posterolateral to ______

A

oblique

anteromedial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What direction would structures be sectioned on coronal images?

A

obliquely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What plane is useful to visualise the length of the ear canal?

A

Off coronal plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What 2 structures does the external ear have?

A

Auricle & External auditory meatus (EAM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Does the EAM extend inwards or outwards to the tympanic membrane?

A

Inwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How long is the EAM and what shape course does it follow?

A

3.7cm long

S-shaped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The EAM outer lateral portion is ______

A

Cartilaginous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What 2 types of glands does the overlying skin of the EAM contain? (C__ & S__)

A

Ceruminous & sebaceous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the tympanic membrane do?

A

Separates middle ear from the EAM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Less than __mm in greatest diameter, the tympanic membrane faces laterally _____ & _____

A

12

downwards & forwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What’s the name of the bony spur formed by the lateral wall of the tympanic cavity & superior wall of EAM.

A

Scutum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Cholesteatoma is formed by the ____ retraction of the pars _____ of the tympanic membrane into the epitympanum

A

medial

flaccida

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What part of the temporal bone is the tympanic cavity/ middle ear located?

A

Petrous part

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Whats the name of the 3 auditory ossicles the tympanic cavity contains?

A

Malleus, incus, stapes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The lateral wall of the tympanic cavity is formed by the ______ _____ and above this by the ____ part of temporal bone

A

tympanic membrane

squamous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the name of the part of the cavity above the tympanic membrane and what 2 ossicles does it contain?

A

epitympanic recess/ attic

incus & head of malleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the medial wall of the middle ear?

A

Round window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The round window is closed by the second tympanic membrane: _____ ______ or ___ window occupied by the base of the _____, the _____ formed by the first part of the cochlea & the prominence caused by the underlying canal for the _____ nerve

A
fenestra vestibuli
oval
stapes
promontory
facial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What structure is attached to the base of the cochlea in the oval window?

A

Stapes footplate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the boundaries of the middle ear?
Lateral
Medial
Superior

A

Lateral: tympanic membrane
Medial: Round window
Superior: epitympanic recess/ attic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which is the largest of the 3 ossicles?

A

Malleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The malleus has a handle attached to the _____ membrane, a rounded head which articulates with the ___ & a lateral process

A

tympanic

incus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What 3 parts does the malleus have?

A

Head, neck & 3 processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

List the 3 processes of the malleus

A
  1. manubrium (handle)
  2. anterior process
  3. lateral process
31
Q

Which 2 of the 3 processes of the malleus are attached to the tympanic membrane?

A

manubrium & lateral process

32
Q

What appearance does the malleus give in axial CT?

A

Ball of ice cream on a cone

33
Q

How many parts does the incus have?

A

3 - body & 2 processes

34
Q

What does the base of the stapes do?

A

Seals the oval window and conducts vibrations to the cochlea.

35
Q

The base of the stapes is attached to the neck via what 2 structures?

A

Anterior & posterior arches

36
Q

What’s the name given to the concave head of the stapes?

A

Capitulum

37
Q

The concave head of the stapes articulates with the ______ nodule of the incus

A

lentiform

38
Q

The malleus articulates to what 2 structures?

A

Tympanic membrane & incus

39
Q

The round window Is closed off from the middle ear by what?

A

The round window membrane

40
Q

What’s the function of the round window?

A

It allows fluid from the cochlea to move so that hair cells of the basilar membrane are stimulated and audition can occur.

41
Q

How does the round window serve as a release valve?

A

It dissipates the pressure generated by the fluid vibrations in the cochlea

42
Q

Where is the round window situated?

A

Below and behind the oval window .

43
Q

Whats another name for the attic/upper portion of tympanic cavity?

A

Epitympanum

44
Q

What does the epitympanum contain?

A

Head of malleus & body of incus

45
Q

Whats the best plane to view the epitympanum?

A

Coronal CT

46
Q

What do you call the portion of the middle ear cavity below the floor of the EAM?

A

Hypotympanum

47
Q

Where do the mastoid air cells lie and open into?

A

Within the mastoid processes & open into mastoid anthrum

48
Q

What does the inner ear consist of?

A

vestibule, cochlea, semicircular ducts

49
Q

The vestibule and semicircular canals are responsible for what?

A

Balance

50
Q

What’s the cochlea responsible for?

A

Hearing

51
Q

Where is the vestibule located?

A

Medial to the oval window

52
Q

What 2 structures is the vestibule composed of?

A

Utricle (posterosuperiorly) & Saccule (inferiorly)

53
Q

What does the utricle communicate with?

A

Semicircular canals

54
Q

What does the saccule communicate with? and via what? (D____ R____)

A

Cochlear duct

via ductus reuniones

55
Q

What shape is the cochlea?

A

Snail-shaped

56
Q

The base corresponds with the bottom of the _____ _____ meatus & is perforated by a number apertures for the passage of the cochlear division of the ______ nerve.

A

Internal acoustic

Acoustic

57
Q

What’s the central axis of the cochlea called?

A

modiolus

58
Q

The o_____ s_____ l____ subdivides the canal into 2 passages.

A

osseous spiral lamina

59
Q

What’s another name for cochlear aqueduct?

A

Cochlea canaliculus

60
Q

What lymphatic duct does the cochlear aqueduct contain?

A

Perilymphatic duct

61
Q

The perilymphatic duct connects with what part of the cochlea with the subarachnoid space? (S____ T____)

A

Scala tympani

62
Q

Where does the cochlear aqueduct open into the subarachnoid space? (something of the jugular foramen? (p__ n____)

A

Beside the pars nervosa of the jugular foramen

63
Q

Where does the cochlear nerve lie In the internal acoustic canal?

A

Anteroinferior portion

64
Q

Where does the cochlear nerve enter prior the spiral ganglia? (m____)

A

Modiolus

65
Q

The upper portion of the posterior semicircular canal forms a common canal ( c____ c___) with the s____ s____ c____ before opening into vestibule

A

Common crus

Superior semicircular canal

66
Q

The eustachian cavity is a communication between what 2 structures?

A

Middle ear cavity & nasopharynx

67
Q

What’s the purpose of the eustachian canal?

A

Allows for aeration & drainage

68
Q

What’s the purpose of the Eustachian tube?

A

Allows the middle ear to normalise with atmospheric pressure

69
Q

What directions does the eustachian canal extend from the tympanic cavity?

A

Downwards, forwards & medially

70
Q

The carotid canal is a passageway in the ____ bone through which the ____ ___ ___ enters the middle cranial fossa from the neck.

A

Temporal

Internal carotid artery

71
Q

Whats the facial nerve responsible for?

A

Motor function of muscles of facial expression
Stapedius muscle
sensation of the skin of ear
taste for ant. 2/3 tongue

72
Q

What are the contents of the Internal auditory canal/ meatus

A
Facial nerve (CN VII|)
Segments of vestibulocochlear nerve  (CN VIII)
73
Q

What canal does the facial nerve leave the IAM?

A

Fallopian canal