Ear

Question 1

What structures do sound waves pass through before reaching the auditory receptors?

Answer 1

External auditory canal - timpani membrane - malleus - incus - stapes - oval window - fluid of inner ear - fluid filled cochlear - sensory hair cells in membrane of spinal organ

Question 2

What is the tympanic membrane?

Answer 2

Fibrous membrane separating the auditory canal from the middle ear

Question 3

Which three bones make up the ossicles?

Answer 3

Malleus
Incus
Stapes

Question 4

What is the function of the ossicles?

Answer 4

To transmit sound from the ear drum to oval window

Question 5

What structure connect ossicles to scala vestibule?

Answer 5

Oval window

Question 6

As stapes footplate moves into oval window the membrane of what moves out?

Answer 6

The round window

Question 7

What does the auditory tube connect?

Answer 7

The nasopharynx to middle ear - equalises pressure between atmosphere and middle ear - drains mucus from inner ear

Question 8

What lines the external auditory canal?

Answer 8

Ear wax

Question 9

what is ear wax made from?

Answer 9

Viscous secretions from sebaceous glands, less viscous from apocrine sweat glands, shed layers of skin, fatty acids, alcohol, squalene and cholesterol

Question 10

What is chorda tympani and what does it innervate?

Answer 10

It is a branch of the facial nerve
It provides taste to the anterior 2/3 of the tongue
parasympathetic supply to submandibular and sublingual glands

Question 11

What forms the lateral wall of the middle ear (air filled chamber)?

Answer 11

Tympanic membrane

Question 12

What is the middle ear connected to posteriorly?

Answer 12

The mastoid air cells

Question 13

Where are the tensor tympani and stapedius muscles located?

Answer 13

The middle ear

Question 14

What is the function and innervation of tensor tympani?

Answer 14

Contraction = pulls handle of malleus medially
Innervation = Trigeminal nerve v3

Question 15

What is the function and innervation of stapedius?

Answer 15

Contraction = pulls stapedius posteriorly
Innervation = facial nerve branch

Question 16

What is the inner ear?

Answer 16

A bony labyrinth - filled with perilymph

Question 17

How many types of receptors are in the membranous labrinth?

Answer 17

3 - maculae

• Christae ampullaris
• Spiral organ

Question 18

Which receptors of the membranous labrinth are vestibular receptors?

Answer 18

Maculae and Christae ampullaris

Question 19

Where are the maculae located?

Answer 19

Utricle and saccule

Question 20

What type of receptor is the spiral organ?

Answer 20

Auditory receptor

Question 21

Which type of receptor is concerned with balance (providing sensory info about the static position of head in space)

Answer 21

Maculae

Question 22

What is the function of Christae ampullaris?

Answer 22

Involved in change in direction and rate of movement

Question 23

What are the similarities between Christae ampullaris and Maculae?

Answer 23

Hair cells have the same morphological forms
Hair cells are supported by single layer of columnar cells
Hair cells have numerous sterocilia

Question 24

What can nystagmus and vertigo be a result of?

Answer 24

Injury to the peripheral vestibulocochlear

Question 25

What is nystagmus?

Answer 25

Rapid involuntary eye movements

Question 26

What is the organ of corti?

Answer 26

Specialised region in the cell wall of the cochlear duct

Question 27

Where does the basilar membrane vibrate if its high frequency noise?

Answer 27

Near end - base (oval window)

Question 28

Where does the basilar membrane vibrate if its low frequency noise?

Answer 28

Far end - apical end (helicotrema)

Question 29

What fibres of the sensory bodies contact the hair cells?

Answer 29

Spiral ganglia