7. External ear (lecture)

Question 1

function of ear?

Answer 1

organ of hearing and balance (equilibrium)

Question 2

what are the different parts of the ear?

Answer 2

external, middle and inner ear

Question 3

what can symptoms of ear disease include?

Answer 3

pain (otalgia)
discharge
hearing loss (conductive VS sensorineural)
tinnitus
vertigo
facial palsy

Question 4

which bone of the skull is the ear in?

Answer 4

temporal

Question 5

what does the external ear consist of?

Answer 5

pinna (auricle)
external auditory (acoustic) meatus
lateral surface of tympanic membrane

Question 6

what happens if the antihelix is damaged?

Answer 6

the ear becomes more protrude (ears stick out more)

Question 7

what is the lobule of the ear?

Answer 7

no cartilage, full of fat

Question 8

which sections of the ear contains least fat?

Answer 8

sections of most curvature - skin closest to cartilage

Question 9

why is the auricle shaped the way it is?

Answer 9

to help funnel sound to EAM

Question 10

what are the different types of abnormalities of the pinna?

Answer 10

congenital
inflammatory
traumatic
infective

Question 11

what is an infective cause of abnormality of pinna of ear?

Answer 11

virus affecting sensory ganglion of the facial nerve - gives rise to vesicles around the external ear
(facial nerve palsy)

Question 12

aside from facial nerve palsy, what is another infective cause of abnormality of pinna of ear?

Answer 12

Ramsay-Hunt syndrome

shingles of the facial nerve (VII)

Question 13

how does pinna haematoma arise?

Answer 13

secondary to blunt injury to the pinna

common in contact sports

Question 14

what happens during pinna haematoma?

Answer 14

accumulation of blood between cartilage and perichondrium

Question 15

what does accumulation of blood between cartilage and perichondrium lead to?

Answer 15

deprives cartilage of its blood supply –> pressure necrosis of tissue

Question 16

what is the treatment for pinna haematoma?

Answer 16

prompt drainage,

measures to prevent re-accumulation and re-apposition of two layers

Question 17

what happens in pinna haematoma? (pathophysiology)

Answer 17

shearing of skin over elastic cartilage
skin pulls with it the perichondrium (away from underlying cartilage)
blood accumulates between perichondrium and cartilage

Question 18

what does untreated or poorly treated pinna haematoma lead to?

Answer 18

fibrosis and new asymmetrical cartilage development - ‘cauliflower ear’

Question 19

what is the external acoustic meatus?

Answer 19

ear canal

a skin-lined cul-de-sac

Question 20

what shape is the external acoustic meatus?

Answer 20

sigmoid shape

need to pull ear up and back to straighten EAM when examining

Question 21

what is the composition of the EAM?

Answer 21

cartilaginous (outer 1/3)
bony part (inner 2/3)

Question 22

what function does the EAM have?

Answer 22

self-cleaning function, to keep ‘pathway’ clear

Question 23

how does EAM carry out self-cleaning function?

Answer 23

the arrangement of hairs and production of wax (within cartilaginous part):

• prevents objects entering deeper into ear canal
• aid in desquamation (shed skin) and skin migration out of canal

Question 24

what is wax?

Answer 24

old and dying epithelial cells that have shed (desquamation) with the sticky secretions from skin cells within EAM

Question 25

how long is the EAM?

Answer 25

2.5cm

Question 26

what are common conditions involving the EAM?

Answer 26

wax

otitis externa

Question 27

what is otitis externa?

Answer 27

infection / inflammation of the ear canal

Question 28

who is prone to otitis externa? why?

Answer 28

swimmers

moist environment - prone to infection

Question 29

what happens in otitis externa?

Answer 29

EAM starts to swell up - cover up tympanic membrane at bottom

Question 30

how does otitis externa present upon examination?

Answer 30

painful

may get discharge from ear

Question 31

how do you treat otitis externa?

Answer 31

antibiotics and or steroid ear drops