Ear

Question 1

What are the 3 sections of the ear?

Answer 1

• External
• Middle
• Inner

Question 2

What structure separates the external and middle ear?

Answer 2

Tympanic membrane

Question 3

What are the parts of the external ear?

Answer 3

• Helix
• Triangular area
• Tragus
• Meatus
• Concha
• Antitragus
• Antihelix
• Lobule

Question 4

What type of cells form the skin of the pinna?

Answer 4

Stratified keratinized epithelium

Question 5

What is present that gives the pinna its structure?

Answer 5

Elastic cartilage

Question 6

How long is the external ear in adults?

Answer 6

4cm

Question 7

What is the lateral 1/3 of the external ear made from?

Answer 7

Skin and cartilage

Question 8

What does the skin of the lateral 1/3 of the external ear contain?

Answer 8

Ceruminous and sebaceous glands

Question 9

What does the lateral 1/3 of the external ear act as?

Answer 9

Protective barrier and disinfectant

Question 10

How do the hairs in the ear differ throughout?

Answer 10

Thick hairs on the outside becoming finer inside

Question 11

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

Answer 11

skin and bone

Question 12

What is not present in the medial 1/3 of the external ear but is in the lateral?

Answer 12

• Hairs

- Cilia

Question 13

What does the medial 1/3 of the external ear not produce?

Answer 13

Wax

Question 14

What constantly happens to the skin of the external ear?

Answer 14

Constantly being shed and renewed

Question 15

Where does the skin of the external ear canal grow from?

Answer 15

Umbo of the tympanic membrane outwards

Question 16

Where is skin of the external ear canal shed from?

Answer 16

Lateral 1/3rd of canal and trapped in wax as part of cleaning mechanism

Question 17

What part of the ear is not very good at sound localisation in humans?

Answer 17

Pinna

Question 18

What causes minimal hearing loss when compared with problems in other parts if the ear?

Answer 18

Wax or mechanical obstructions

Question 19

Name the parts of the tympanic membrane?

Answer 19

• Posterior fold
• Incus
• Umbo
• Annulus
• Pars tensa
• Cone of light
• Manubrium of malleus
• Short process of malleus
• Anterior fold
• Pars flaccida

Question 20

What are the 3 layers of the tympanic membrane?

Answer 20

• Outer layer that is continuous with kin of EAC
• Middle fibrous layer
• Inner layer of respiratory epithelium (ciliated columnar epithelium with goblet cells)

Question 21

How thick is the tympanic membrane?

Answer 21

1/10th of a millimeter

Question 22

What diameter is the tympanic membrane?

Answer 22

1cm

Question 23

What are the 3 bones found in the inner ear?

Answer 23

• Head of malleus
• Incus
• Stapes

Question 24

What do the ossicles do?

Answer 24

• Conduct sound waves from tympanic membrane to inner ear

- Play a very important role in sound conduction

Question 25

What can disruption of the ossicles be from?

Answer 25

Trauma or bony sclerosis (otosclerosis)

Question 26

What is the middle ear lined with?

Answer 26

Same continuous respiratory epithelium that forms inner layer of tympanic membrane

Question 27

What is the middle ear capable of producing?

Answer 27

Mucous

Question 28

What can the production of excess mucous in the middle ear lead to?

Answer 28

Glue ear

Question 29

What does the middle ear connect to the mastoid system via?

Answer 29

Aditus

Question 30

What does the middle ear connect to the nasopharynx via?

Answer 30

Eustachian tube

Question 31

What nerve foes the middle ear contain?

Answer 31

Chorda tympani branch of the facial nerve

Question 32

What are the most important relations of the middle ear?

Answer 32

- Middle cranial fossa - Internal carotid artery - Sigmoid sinus and internal jugular vein

Question 33

What are the 6 segment of the facial nerve?

Answer 33

- Intracranial - Meatal segment (internal auditory meatus) - Labyrinthine segment - Tympanic segment (Fallopian tube. 10% which are dehiscent) - Mastoid segment - Extratemporal segment

Question 34

What does the facial nerve supply motor function to?

Answer 34

Muscles of facial expression - Stapedius - Posterior belly of digastric - Stylohyoid

Question 35

Where does the anterior 2/3rds of the tongue receive taste from?

Answer 35

Chorda tympani

Question 36

What structures can be affected by complications of otitis media and cholesteatoma?

Answer 36

- Meninges - Middle cranial fossa - Facial nerve - Mastoid cavity - Inner ear - Sigmoid sinus/internal jugular vein

Question 37

Cholesteatoma

Answer 37

Keratinised squamous epithelium (skin) in the wrong place

Question 38

How does cholesteatoma cause problems?

Answer 38

They grow and are destructive

Question 39

What are the 2 types of cholesteatoma?

Answer 39

- Congenital | - Acquired

Question 40

What nerve is associated with the inner ear?

Answer 40

Vestibulocochlear nerve (CN VIII)

Question 41

What are the components of the inner ear?

Answer 41

- Bony and membranous labyrinth - Cochlear - Peripheral vestibular apparatus

Question 42

Cochlear

Answer 42

Organ of corti- hearing organ

Question 43

What are the 3 components of the peripheral vestibular apparatus?

Answer 43

- Utricle - Saccule - Semi-circular canals

Question 44

What does the membranous labyrinth of the inner ear contain?

Answer 44

Fluid - Perilymph - Endolymph

Question 45

What is the function of the middle ear?

Answer 45

Transduce vibration into nervous impulses

Question 46

What is the physiology of hearing following the transduction of vibration into nervous impulses by the middle ear?

Answer 46

- Foot of stapes vibrates in oval window - Causes pressure wave through fluid in cochlear - This is detected by hair cells in organ of corti - Transmitted to brainstem by CN VIII

Question 47

What is responsible for detecting head rotation?

Answer 47

Semi-circular canals

Question 48

Vestibulo-occular reflex

Answer 48

What makes you able to fix your vision on an object even when your head is moving

Question 49

What does the saccule detect?

Answer 49

Linear acceleration in vertical plane

Question 50

What does the utricle detect?

Answer 50

Linear acceleration in horizontal plane

Question 51

What is another name for the tympanic branch of the glossopharyngeal nerves CN IX?

Answer 51

Jacobson's nerve

Question 52

What is Jacobson's nerve responsible for?

Answer 52

Sensation to middle ear

Question 53

What is another name for the auricular branch of the vagus nerve CN X?

Answer 53

Arnold's nerve

Question 54

What is Arnold's nerve responsible for?

Answer 54

Sensation to posterior half of EAC

Question 55

What is the facial nerve responsible for?

Answer 55

Anterior half of EAC

Question 56

What is the mandibular branch of the trigeminal nerve responebile for CN V3?

Answer 56

Pinna

Question 57

When can otalgia be a worrying sign?

Answer 57

In the absence of an obvious ear cause as it could be due to head and neck cancer