Ear

Question 1

How many parts is the ear split into and what are they?

Answer 1

3

External, middle and inner

Question 2

What is the medical term for ear pain?

Answer 2

Otalgia

Question 3

What are the 2 types of hearing loss?

Answer 3

Conductive

Sensorineural

Question 4

The ear is within which bone?

Answer 4

Petrous part of the temporal bone

Question 5

The external ear runs from … to…

Answer 5

Pinna/auricle to the tympanic membrane

Question 6

What is the role of the external ear?

Answer 6

Collect, transmit and focus sound waves onto the tympanic membrane

Question 7

What do we call the fold at the very top of the outer ear?

Answer 7

Helix

Question 8

What do we call the dangly bottom part of the external ear?

Answer 8

Lobule

Question 9

Describe the composition of the pinna

Answer 9

Elastic cartilage with skin closely adhered to it

Question 10

When do you get Boxer’s/Cauliflower ear?

Answer 10

After repeated trauma to the ear

Question 11

What is Ramsay-Hunt syndrome?

Answer 11

Infection
Shingles of the facial nerve
Causes vesicles is ear and facial nerve palsy

Question 12

What is a pinna haematoma and why is it dangerous?

Answer 12

Secondary to blunt injury to pinna
Accumulation of blood between cartilage and perichondrium
Perichondrium supplies blood to cartilage therefore this can lead to loss of blood supply and/or pressure necrosis of the cartilage

Question 13

What Mx do we need for pinna haematoma?

Answer 13

Prompt drainage
Measures to prevent reaccumulation
Reapposition of the 2 layers

Question 14

Describe the structure of the external acoustic meatus

Answer 14

Skin lined curl-de-sac 
keratinised
Sigmoid shape 
Cartilaginous outer 1/3
Bony inner 2/3

Question 15

How do we straighten the ear to look inside?

Answer 15

Pull the ear up and back

Question 16

How does the EAM self clean?

Answer 16

Ear wax

Migration to outer part

Question 17

What is the length of the EAM?

Answer 17

2.5 cm

Question 18

What is otitis externa?

Answer 18

Very common
Infection and inflammation - ear canal swells, very painful
‘Swimmer’s ear’
Can be hard to tolerate the ear examination
Treat with ear drops: Abx or steroid

Question 19

Describe the tympanic membrane

Answer 19

Pearly, translucent, tightly stretched, fibrous CT

Question 20

What features can be seen looking at the tympanic membrane?

Answer 20

Long process of incus 
Handle of malleus (middle)
Pars flaccida (loose tissue above malleus) 
Pars Tessa 
Cone of light

Question 21

What compromises the middle ear?

Answer 21

Ossicles

Air filled cavity - tympanic cavity

Question 22

What is the role of the ossicles?

Answer 22

Amplify vibration from membrane to cochlea via the oval window

Question 23

What is the order that vibrations travel through the ossicles?

Answer 23

Malleus > incus > stapes

Question 24

What is the Eustachian tube?

Answer 24

Allows equilibration of pressure in middle ear with the atmosphere
Ventilation and drainage of mucus
Middle ear to nasopharynx

Question 25

Describe otitis media with effusion

Answer 25

(Glue ear) Not an actual infection Build up of fluid and negative pressure in middle ear Eustachian tube dysfunction Decreased mobility of membrane and ossicles - affects hearing Most resolve spontaneously - some need grommets

Question 26

Describe otitis media

Answer 26

``` Acute middle ear infection More common in infants/children Otalgia Temperature Red +/- bulging T membrane and loss of features of TM ```

Question 27

Why are middle ear infections more common in children?

Answer 27

Eustachian tube is shorter and more horizontal

Question 28

What are some complications of otitis media?

Answer 28

TM perforation Facial nerve palsy Rare = mastoiditis, meningitis

Question 29

What are mastoid cells?

Answer 29

Air cells of bone that communicate with the middle ear

Question 30

Describe mastoiditis

Answer 30

Red and swollen behind ear Ear pushed forward Refer straight to hospital

Question 31

Which part of the facial nerve runs through the middle ear and what does it supply?

Answer 31

Chorda tympani branch | Supplies taste to anterior 2/3 tongue

Question 32

What is a cholesteatoma?

Answer 32

Skin cells get trapped and grow - small pocket forms at top of middle ear Not malignant but slowly erodes into structures eg. Ossicles Usually secondary to recurring/chronic ear infections

Question 33

What makes up the inner ear?

Answer 33

Vestibular apparatus and cochlea

Question 34

What is the role of the vestibular apparatus?

Answer 34

Sense of position and balance

Question 35

What is the role of the cochlea?

Answer 35

Converts sound vibrations into electrical signals

Question 36

How many semicircular canals do we have?

Answer 36

3

Question 37

Where are the special sensory cells of the ear?

Answer 37

In the cochlear duct

Question 38

Where is the problem with sensorineural hearing loss?

Answer 38

Cochlear or nerve supplying it

Question 39

Where is the problem in conductive hearing loss?

Answer 39

External or middle ear

Question 40

Describe how sound moves from vibrations to the brain

Answer 40

Vibration of ossicles Movement of cochlear fluid Sensed by nerve cells of cochlear duct in spiral organ of Corti Trigger APs in the vestibulocochlear nerve (VIII) To the brain

Question 41

Why do we have 3 semicircular canals?

Answer 41

Arranged in different planes | Sense different movements

Question 42

Give some problems with the vestibular apparatus

Answer 42

Vertigo Ménière's disease Benign paroxysmal positional vertigo