Anatomy and physiology of hearing

Question 1

What is the pinna?

Answer 1

The visible part of the ear

Question 2

What is the epithelium of the pinna?

Answer 2

Stratified keratinised squamous

Question 3

What is the pinna not good at?

Answer 3

Sound localisation

Question 4

What is the lateral 2/3 of the external ear made of?

Answer 4

Skin, containing ceruminous and sebaceous glands and hairs, and cartilage

Question 5

What is the medial 1/3 of the external ear made of?

Answer 5

Skin and bone

No hairs of cilia

Question 6

What happens to the skin on the external ear?

Answer 6

IS constantly being shed in the lateral 1/3 of the canal and trapped in wax as part of the cleaning mechanism

Question 7

How many layers does the tympanic membrane have?

Answer 7

3

Question 8

What is the outer layer of the tympanic membrane?

Answer 8

Skin continuous with the external auditory canal

Question 9

What is the middle ayer of the tympanic membrane?

Answer 9

Fibrous layer

Question 10

What is the inner layer of the tympanic membrane?

Answer 10

Resp epithelium- ciliated columnar with goblet cells

Question 11

What is the size of the tympanic membrane?

Answer 11

1cm diameter and 1/10th mm thick

Question 12

What is the tympanic membrane the division between?

Answer 12

External and middle ear

Question 13

What is the function of the ossicles?

Answer 13

Conduct sound waves from tympanic membrane to inner ear

Play a very important role in sound conduction

Question 14

What can cause disruption of the ossicles?

Answer 14

Trauma

Bony sclerosis- otosclerosis

Question 15

What is the middle ear lines with

Answer 15

Respiratory epithelium

Question 16

What does the middle ear connect with?

Answer 16

Mastoid system

Nasopharynx

Question 17

How does the middle ear connect with the mastoid system?

Answer 17

Via audits

Question 18

How does the middle ear connect with the nasopharynx?

Answer 18

Via Eustachian tube

Question 19

What does the middle ear contain?

Answer 19

Facial nerve CN VII

Question 20

What are the 6 segments of the facial nerve?

Answer 20

Intracranial
Meatal
Labyrinthine
Tympanic
Mastoid
Extratemporal

Question 21

Where is the metal segment of the facial nerve?

Answer 21

Internal auditory meatus

Question 22

Where is the tympanic segment of the facial nerve?

Answer 22

Runs through fallopian tube

Question 23

What does the facial nerve supply?

Answer 23

Muscles of facial expression

Taste to the anterior 2/3 of the tongue via chord tympani

Question 24

What are the most important relations of the middle ear?

Answer 24

Middle cranial fossa
Internal carotid
Sigmoid sinus and internal jugular

Question 25

What is the internal ear?

Answer 25

Bony and membranous laryrinth

Question 26

What does the membranous labyrinth contain?

Answer 26

Fluid- perilymph and endolymph

Question 27

What is the cochlea?

Answer 27

Spiral shaped cavity in the bony labyrinth

Question 28

What is contained in the peripheral vestibular apparatus?

Answer 28

Itricle Saccule Semicircular canals

Question 29

What is the function of the middle ear?

Answer 29

Transduce vibration into nervous impulses

Question 30

How is hearing transduced?

Answer 30

Foot of stapes vibrates in oval window, causing pressure wave through fluid in cochlea detected by hair cells in the organ of corti This is transmitted to brainstem via CN VIII

Question 31

What parts of the ear are involve in balance?

Answer 31

Semicircular canal

Question 32

What is the vestibule-ocular reflex?

Answer 32

What makes ou able to fix your eyes on an object even when your head is moving

Question 33

What does the saccule do?

Answer 33

Detects linear acceleration in the vertical plane

Question 34

What does the utricle do?

Answer 34

Detects linear acceleration in the horizontal plane

Question 35

What provides sensation to the middle ear?

Answer 35

Tympanic branch of the glossopharyngeal nerve

Question 36

What provides sensation to the posterior half of the external auditory canal?

Answer 36

Auricular branch of the vagus nerve

Question 37

What provides sensation to the anterior half of the external auditory canal?

Answer 37

Facial nerve

Question 38

What gives sensation to the pinna?

Answer 38

Mandibular branch of trigeminal nerve