Anatomy Of The Ear

Front 1

Endolymph

Back 1

Fluid that fills the cochlear duct

Front 2

Annular ligament

Back 2

Fastens footpath of stapes to bony wall of oval window

Front 3

Approximately how many hair cells in the organ of corti?

Back 3

5,000 inner hair cells and 10,000 outer hair cells

Front 4

What is the normal condition of the eustatian tube?

Back 4

Usually closed

Front 5

The ear is most accurately considered to be what?

Back 5

The organ of hearing and equillibrium

Front 6

What is the ratio of difference in the size between the tympanic membrane and the oval window?

Back 6

17:1

Front 7

Ceruman has its origin where?

Back 7

External auditory meatus

Front 8

The most protruding landmark on the tympanic membrane is what?

Back 8

The lateral process of the malleolus

Front 9

The essential parts of the organ of hearing and balance is located where?

Back 9

Temporal bone

Front 10

Epitympanic recess

Back 10

Also called the attic, filled by head of malleus and much of the incus

Front 11

Perilymph

Back 11

A

Front 12

Basilar membrane

Back 12

A

Front 13

Ossicular chain

Back 13

Made up of the 3 small bones of the inner ear. They serve as a mechanical link between the tympanic membrane and the inner ear

Front 14

A

Back 14

Superior

Front 15

B

Back 15

Anterior

Front 16

C

Back 16

Posterior

Front 17

D

Back 17

Medial

Front 18

E

Back 18

Lateral

Front 19

F

Back 19

Proximal

Front 20

G

Back 20

Distal

Front 21

H

Back 21

Inferior

Front 22

Blue

Back 22

Coronal plane

Front 23

Green

Back 23

Transverse plane

Front 24

Pink

Back 24

Saggittal plane

Front 25

A

Back 25

Reissner's membrane

Front 26

B

Back 26

Stria vascularis

Front 27

C

Back 27

Scala media

Front 28

D

Back 28

Tectonics membrane

Front 29

E

Back 29

Organ of corti

Front 30

F

Back 30

Basilar membrane

Front 31

F

Back 31

Basilar membrane

Front 32

G

Back 32

Scala tympani

Front 33

H

Back 33

Spiral limbus

Front 34

I

Back 34

Scala vestibulli

Front 35

A, B, C

Back 35

A- head or shoulder of malleus

B- anterior process of the malleus

C- lateral process of the malleus

Front 36

D, E, F

Back 36

D- mannerism of malleus

E- footplate of stapes

Front 37

F, G, h, i

Back 37

F - head or neck of stapes

G - incudostapedial joint or junction

H- long process of the incus

Ì short process of the incus

Front 38

A

Back 38

Pars tensa

Front 39

B

Back 39

Pars flaccid a or sharpness membrane

Front 40

D

Back 40

Shadow of the malleus or manubrium of the malleus

Front 41

E

Back 41

Cone of light

Front 42

1, 2, 3, 4, 5

Back 42

1-external auditory meatus or canal

2-tympanic membrane or eardrum

3-malleus

4-incus

5-stapes

Front 43

6, 7, 8, 9, 10

Back 43

6- ligament

7-eustaciah tube

8-oval window

9-round window

10-cochlea

Front 44

11, 12, 13, 14, 15

Back 44

10-cochlea nerve

12-semicircular canals

13-utricle

14-balance/vestibular nerve

15-balance/vestibular nerve

Front 45

16, 17, 18, 18, 20

Back 45

16-facial nerve17-temporal bone18-muscle19-cartilage20-internal auditory meatus or canal

Front 46

21, 22, 23

Back 46

21-earlobe or lobule

22-external ear, pinna, auricle

23-pinna or helix

Front 47

1, 2, 3

Back 47

1-helix

2-scaphoid fossa

3-antihelix

Front 48

4, 5, 6

Back 48

4-darwin's turbercle

5-triangular fossa

6-crus

Front 49

7, 8, 9

Back 49

7-cymba of concha

8-cavum of concha

9-aperature

Front 50

10, 11, 12, 13

Back 50

10-tragus

11-anti-tragus

12-lobule

13-pinna

Front 51

What is the shape of the ear canal?

Back 51

S shaped, backward and upward, then slightly forward and downward

Front 52

Where is the ear canal the most narrow?

Back 52

At the isthmus

Front 53

What are the dimensions of the adult ear?

Back 53

28-30mm in length 6-8mm in diameter

Front 54

What is Arnolds branch?

Back 54

A branch of the vagus nerve along the floor of the ear canal, can cause reflex such as cough, sneeze, pain, ill feeling.

Front 55

How much of the external ear is cartilage?

Back 55

1/2-2/3

Front 56

How much of the external ear is the Osseous (boney) portion?

Back 56

1/2-1/3

Front 57

What 3 things are found in the ear canal?

Back 57

Sebaceous glads, ceruman glands, and hair cells.

Front 58

What purpose does the cartilaginous portion of the ear serve? (3 things)

Back 58

-protects ear canal from drying out

-secretions and hairs act as a bug repellant

-hairs, jaw movement, and lateral migration of skin move dry particles towards entrace

Front 59

What purpose does the Osseous (boney) portion of the ear canal serve? (2 things)

Back 59

-Keeps canal from collapsing

-helps protect internal ear strucures

Front 60

What purpose does the EAC serve? (3 things)

Back 60

-directs sound

-protects

-natural amplification

Front 61

Most adult EAC'S resonate between

Back 61

2000-3000Hz

Front 62

The pinna naturally resonates between

Back 62

2000-5000Hz

Front 63

On average, the EAC and pinna together, have a natural resonance of what? It will provide a boost in sound up to what?

Back 63

2700Hz

15dB

Front 64

Middle ear consists of (4 things)

Back 64

Tympanic membrane

Ossicular chain

Tensor tympani muscle

Stapedius muscle

Front 65

Where is the Ossicular chain housed?

Back 65

Epitympanic recess / attic

Front 66

Characteristics of the tympanic membrane (list 6)

Back 66

Oval shape

Slightly convex

Separates ear canal from middle ear

About .1mm thick

45-55 degree angle

Made up of 3-4 layers

Front 67

Describe the outer layer of the tympanic membrane

Back 67

Thick cutaneous layer continuous with skin of ear canal

Front 68

Describe the 2 middle layers of the tympanic membrane

Back 68

Both are fiberous

Inner layer is concentric rings

Outer layer fibers radiate from center out

Front 69

What are the four quadrants of the tympanic membrane

Back 69

Posterior superior

Anterior superior

Posterior inferior

Anterior inferior

Front 70

Cone of light

Back 70

Light reflect on the tympanic membrane during otoscopy

Front 71

Annulus

Back 71

Incomplete ring of bone holding the tympanic membrane in place

Front 72

Umbo

Back 72

Manubrium of the malleus

Front 73

Pars flaccida

Back 73

Small flaccid triangular shaped area at the top edge of the tympanic membrane

Front 74

Pars tensa

Back 74

The tense greater part of the eardrum

Front 75

When performing otoscopy what things do you need to look for on the tympanic membrane? (List 5)

Back 75

-grayish or pinkish in color

-more concave than convex

-a shadow of manubrium of malleus

-umbo

-cone of light

Front 76

Malleus

Back 76

Largest of the three bones in the middle ear, I'm bedded in the fiberous layer of the eardrum

Front 77

Incus

Back 77

One of the bones of the middle ear, joins the malleus to the stapes

Front 78

Stapes

Back 78

Smallest bones in the human body, connects to the incus in the Ossicular xhair. The footpath of the stapes is fixed in the oval window of the inner ear

Front 79

Ossicular vibration

Back 79

The vibration of the eardrum is transmitted to the oval window of the inner ear by means of the ossicles

Front 80

What is the primary function of the ossicles?

Back 80

Compensate for the impedance mismatch between the low impedance of acoustic energy (air pressure waves) and the high impedance of the hydraulic, fluid filled system of the cochlea.

Front 81

How does the middle ear overcome impedance mismatch? (List 3)

Back 81

-Funneling action from eardrum to oval window provides a 15-20dB boost to sound as it travels through the inner ear

-the malleus provides a fulcrum like action, which magnifies sound about 5dB

-the buckling effect of the tympanic membrane, as a result of not being completely attached to the malleus, creating a 10dB boost

Front 82

Basilar membranr

Back 82

Separates cochlear duct from the scala tympani

Front 83

Organ of corti (list 3)

Back 83

-Sits on the basilar membrane in the scala media

-contains 4-6 rows of hair cells

-above the hair cells is the tectonics membrane

Front 84

The Ossicular chain is supported by

Back 84

Ligaments and two muscles; the stapedius, and the tensor tympani.

Front 85

Stapedius

Back 85

Muscle that attaches to the stapes and draws the stapes in a posterior direction when it contracts

Front 86

Tensor tympani

Back 86

Muscle that atravges to the malleus, when contracted it pulls in opposition to the stapedius muscle, thereby tightening the tympanic membrane

Front 87

What is impedance mismatch?

Back 87

Resistance to flow due to the difference of air and fluid

Front 88

What would happen if we did not have a middle ear?

Back 88

Everyone would have a 30-40dB hearing loss

Front 89

Because of the delicate nature of the suspension within the middle ear cavity, it is vulnerable to

Back 89

Trauma and disease

Front 90

Acoustic reflex

Back 90

provides some protection to the ear from loud sounds, only occurs for signals around 85dB or louder.

Front 91

Explain the eustachian tube

Back 91

-The middle ears air pressure equalization system

-runs from middle ear cavity down to the josopharynx (upper part of the throat, behind the nose)

-is normally closed, but opens about every 2-3 you swallow

Front 92

What happens If the eustachian tube does not function properly (list 4)

Back 92

-the middle ear remains in a state of negative pressure or a partial vacuum

-the TV retracts

-Ossicular chain doesn't work as well

-the negative pressure draws fluid from the mucous membrane lining from middle ear cavity

Front 93

What is the bony labyrinth?

Back 93

A series if channels and chambers embedded within the temporal bone

Front 94

The cochlea changes mechanical sound energy into what?

Back 94

A sequence of electrical discharges that is the language of the auditory nervous system.

Front 95

The cochlea is divided lengthwise into three channels by what two membranes?

Back 95

Basilar membrane and reissner's membrane

Front 96

What are the three channels of the cochlea?

Back 96

Scala vestibule

Scala tympani

Cochlear duct

Front 97

Scala vestibule

Back 97

-The channel formed by the upper bony wall of the cochlea

-filled with perilymph

Front 98

Scala tympani

Back 98

-The channel between the basilar membrane and the lower bony wall

-filled with perilymph

Front 99

Scala media {Cochlear duct} (list 3)

Back 99

-The third channel which separates the Scala tympani and the scala vestibule

-lies between the basilar membrane and the reissner's membrane

- filled with endolymph

Front 100

The oval window leads from where, to where?

Back 100

From the missile ear directly into the scala vestibuli

Front 101

Round window

Back 101

Leads directly into the scala tympani, on the other side of the cochlear duct, opposite the oval window

Front 102

Membraneous labyrinth (2 parts)

Back 102

Fluid filled membrane that sits inside the bony labyrinth, which houses the functional part of the cochlea

Front 103

What is known to be true about otosclerosis? (List 3)

Back 103

It is more common in women than men

Reduced ability to understand children

Difficulty hearing in noisy and quiet environments

Front 104

What is the isthmus?

Back 104

Where the canal narrows to enter the temporal bone