15b. Inner Ear, Hearing, Vestibular Function Flashcards Preview

NSB > 15b. Inner Ear, Hearing, Vestibular Function > Flashcards

Flashcards in 15b. Inner Ear, Hearing, Vestibular Function Deck (48)
Loading flashcards...
1

What is presbycusis?

Age-related bilateral hearing impairment
Unable to hear frequencies below 1500 Hz

2

What are the risk factors for presbycusis?

Noise exposure
Ototoxins
Infections
Smoking, hypertension, vascular disease, diabetes
Immunological disorders
Genetics (mtDNA)

3

What is sensorineural presbycusis?

Degeneration of the cilia on hair cells of organ of Corti or loss of cochlear nerve fibres

4

What is conductive presbycusis?

Stiffening of the basilar membrane of the cochlea or ossicles

5

What is metabolic presbycusis?

Atrophy of the stria vascularis
Loss of resting potential of endolymph

6

What is the treatment for presbycusis?

Ear protection, avoid loud noises
Assistive devices
Lip reading
Amplification devices and cochlear implants

7

What is the function of hearing aids?

Amplify waves in the outer ear and auditory canal

8

What are the parts of a hearing aid?

Microphone, amplifier, speaker

9

What is the use of both a hearing aid and a cochlear implant called?

Electric Acoustic Stimulation

10

What is the function of a cochlear implant?

Capture and convert sound to electrical signals
Goes to electrode array in cochlea via a stimulator

11

What type of energy does the vestibular system rely on?

Hydraulic

12

What is the name of the sensory epithelium of the ampulla of the semi-circular canals?

Crista ampullaris

13

What does the crista ampullaris detect?

Angular acceleration (rotation)

14

What are the utricle and saccule collectively known as?

Otolith organs

15

What do the otolith organs detect?

Position of the head with respect to gravity (linear acceleration)

16

What does the superior semi-circular canal detect?

Up and down movements

17

What does the posterior semi-circular canal detect?

Head tilting to one shoulder

18

What does the horizontal semi-circular canal detect?

Head turning side to side

19

What is the name of the gelatinous mass that surrounds the crista ampullaris?

Cupula

20

What happens to the endolymph when the semi-circular canals rotate?

Endolymph stays still
Pushes against cupula which bends stereocilia of hair cells

21

What happens when the stereocilia are pushed against the kinocilium?

Influx of K+ and Ca+ via mechanoceptors causes depolarisation
Release of glutamate activates the vestibular nerve

22

What happens in the opposite ear to the one with the activated vestibular nerve?

Stereocilia bend away from the kinocilium
Hair cells hyperpolarise

23

What are the Otolith Organs?

Membranous labyrinths within the vestibule

24

What is the saccule connected to?

Scala media

25

What is the utricle connected to?

Semi-circular ducts

26

What is the name of the sensory epithelium in the otolith organs?

Macula

27

What is the macula composed of?

Supporting cells, sensory hair cells, vestibular dark cells

28

What surrounds the macula?

Otolithic membrane

29

Describe the make-up of the otolithic membrane

Gelatinous
Contains calcium carbonate crystals (otoliths, otoconia)

30

What plane do the macular hair cells project into in the utricle?

Vertical