Anatomy/Physiology of Ear

Question 1

What is the epithelium of the external ear?

Answer 1

Stratified keratinising squamous epithelium

Question 2

What is the lateral 1/3rd of the external auditory meatus composed of?

Answer 2

Skin and cartilage

Question 3

What does the skin of the external auditory meatus contain for producing wax?

Answer 3

Ceruminous and sebaceous glands

Question 4

Hairs of the external auditory meatus provide

Answer 4

a barrier and source of disinfectant

Question 5

Medial 1/3rd of external auditory meatus is composed of

Answer 5

skin and bone

Question 6

Where does the skin of the external auditory meatus grow from?

Answer 6

From the jumbo of the tympanic membrane outwards

Question 7

Where is the skin of the external auditory meatus shed?

Answer 7

Lateral 1/3rd of the canal, trapped in the wax as part of cleaning

Question 8

What is the epithelial lining of the external ear canal?

Answer 8

Simple squamous epithelium

Question 9

Components of the middle ear

Answer 9

Eustachian tube
Tympanic membrane
Mastoid bone
Ossicles - malleus, incus and stapes

Question 10

What is the epithelial lining of the eustachian tube?

Answer 10

Respiratory epithelium that becomes pseudostratified as it approaches the nasopharynx

Question 11

Layers of the tympanic membrane

Answer 11

Outer squamous epithelial layer
Middle fibrous connective tissue
Inner columnar ciliated mucous membrane

Question 12

Function of the ossicles

Answer 12

Sound conduction

Question 13

What might occur as a result of trauma to the ossicles?

Answer 13

Chronic suppuration

Bony sclerosis

Question 14

What is the epithelial lining of the middle ear?

Answer 14

Columnar ciliated epithelium

Question 15

Contents of the middle ear

Answer 15

Ossicles
Facial nerve
Chorda tympani

Question 16

Connections of the middle ear

Answer 16

To the mastoid system via the aditus, to post-nasal space via Eustachian tube

Question 17

Important relations of the middle ear

Answer 17

Middle fossa
Internal jugular vein
Internal carotid artery

Question 18

What are the possible consequences of damage to the ear/facial nerve in surgical treatment of the ear

Answer 18

Infection 
Trauma 
Intracranial sepsis
Facial nerve damage 
Deafness 
Dizziness

Question 19

What are the contents of the bony labyrinth of the inner ear?

Answer 19

Cochlea
Vestibule
Semi-circular canal

Question 20

What fluids are contained within the membranous labyrinth?

Answer 20

Perilymph

Endolymph

Question 21

Audiometry measures

Answer 21

hearing acuity for changes in amplitude/intensity and frequency of sound

Question 22

Tympanometry measures

Answer 22

tympanic membrane compliance

Question 23

Children born deaf will not be able to develop normal speech unless hearing is restored by what age?

Answer 23

4

Question 24

Where does the cochlear nerve join the brainstem?

Answer 24

At the junction of the pons and medulla

Question 25

What nerves supply innervation to the ear?

Answer 25

Cervical nerve root branches Trigeminal Glossopharyngeal Vagus

Question 26

What is the basic pathway affected in conductive hearing loss?

Answer 26

Ear canal -> tympanic membrane -> ossicles

Question 27

What is the basic pathway affected in sensorineural hearing loss?

Answer 27

Cochlea -> cochlear nerve -> auditory cortex