Anatomy and physiology of hearing

Question 1

3 main divisions of the ear and how you look in the ear

Answer 1

external, middle and inner

otoscope, microscope and speculum

Question 2

pinna/auricle

Answer 2

Visible part of the ear from the outside

Question 3

Name the outer visible parts of the ear

Answer 3

helix, triangular area, antihelix, lobule, tragus, concha, meatus and antitragus

Question 4

Skin epithelium

Answer 4

stratified keratinised epithelium

Question 5

What underlies the skin to give the pinna its structure?

Answer 5

elastic cartilage

Question 6

External ear canal length

Answer 6

4cm long in adult

Question 7

Lateral 1/3 of ear

Answer 7

cartilage and skin with ceruminous and sebaceous glands

Question 8

Hair changes through the ear

Answer 8

thick on outside and finer inside

Question 9

Hair purpose in ear

Answer 9

disinfectant and barrier

Question 10

Medial 1/3 of ear

Answer 10

no hairs, cilia or wax

made of skin and bone

Question 11

Where does skin grow from in the ear?

Answer 11

umbo in the tympanic membrane outwards

Question 12

Where is the skin in ear shed?

Answer 12

lateral 1/3 and trapped in wax

Question 13

Pinna haematoma

Answer 13

rugby ear

trauma separates cartilage and tears blood vessels

Question 14

Outer, middle and inner layers of tympanic membrane

Answer 14

continuous with skin of EAC
fibrous layer
respiratory epithelium

Question 15

dimensions of the tympanic membrane

Answer 15

1cm in diameter, 1/10 mm thick

Question 16

ossicles part

Answer 16

head of malleus, incus and stapes

Question 17

What is the clinical condition related to the respiratory epithelium of the middle ear?

Answer 17

glue ear due to mucous

Question 18

How is the middle ear connected to a) mastoid system and b) nasopharynx

Answer 18

a) aditus

b) Eustachian tube

Question 19

purpose of middle ear

Answer 19

conduct sound from tympanic membrane to the inner ear - SOUND CONDUCTION

Question 20

How can the middle ear be disrupted?

Answer 20

otosclerosis or trauma

Question 21

contents of the middle ear - nerve

Answer 21

facial nerve –> chorda tympani

Question 22

most important relations of the middle ear

Answer 22

middle cranial fossa, internal carotid artery, sigmoid sinus + internal jugular vein

Question 23

how many segments of the facial nerve?

Answer 23

6

Question 24

Which facial nerve segment has a fallopian tube which is 10% dehiscent?

Answer 24

tympanic

Question 25

Where does the facial nerve exit through the skull?

Answer 25

stylomastoid foramen

Question 26

What does the facial nerve supply?

Answer 26

motor supply of muscles of facial expression | taste anterior 2/3 tongue from chorda tympani

Question 27

Anatomical relations - complications of otitis media and cholesteatoma

Answer 27

meninges, middle cranial fossa, facial nerve, mastoid cavity, inner ear and sigmoid sinus/IJV

Question 28

What is cholesteatoma?

Answer 28

skin in wrong place - keratinised squamous epithelium in middle ear

Question 29

Cholesteatoma congenital or acquired?

Answer 29

both

Question 30

Inner ear parts

Answer 30

bony and membranous labyrinth cochlear peripheral vestibular apparatus vestibulocochlear nerve

Question 31

Membranous labyrinth fluid

Answer 31

perilymph and endolymph

Question 32

hearing organ and balance organ

Answer 32

cochlear | peripheral vestibular apparatus

Question 33

Parts of peripheral vestibular apparatus

Answer 33

utricle, saccule and semicircular canal

Question 34

Briefly describe hearing

Answer 34

middle ear vibration --> nerve impulses foot of stapes vibrates in oval window pressure wave through fluid in cochlear detected by hair cells in organ of corti transmitted by brainstem by vestibulocochlear nerve

Question 35

Explain the importance of each part of the peripheral vestibular apparatus in balance

Answer 35

semi circular canals - head rotation saccule - vertical plane utricle - horizontal plane

Question 36

sensation to middle ear nerve

Answer 36

jacobsons nerve - glossopharyngeal tympanic branch

Question 37

sensation to posterior half of EAC nerve

Answer 37

Arnold's nerve - auricular branch of vagus nerve

Question 38

anterior half of EAC sensation nerve

Answer 38

facial nerve

Question 39

pinna nerve supply

Answer 39

CN V3

Question 40

Why is shared innervation of the nerve supply important?

Answer 40

otalgia worrying if no ear cause | head and neck cancer