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Flashcards in the ear, hearing & balance Deck (13)
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1

outer ear

pinna- visible part, funnel
ear canal

2

middle ear

ear drum- sound waves to vibrations
ossicles- 3 types: malleus(hammer), incas(anvil|), stapes(stirup)

3

inner ear

cochlea- vibrations into electrical signals, filled with liquid, wider part senses higher pitches
auditory nerve- transports electrical signal to brain
eustation tube- brings in air from nose

4

average hearing frequency

20-20000Hz

5

decibels

measurement of intensity of noise

6

noise induced hearing loss (NIHL)

temporary
depends on intensity, frequency and duration of exposure
over exposure to 8hrs+ at >85-90dB
sudden exposure to >120dB
could even burst ear drums

7

conductive hearing loss

hearing works on conduction
can be blocked: wax, ear infection, hole in ear drums, damaged cochlea
temporary
perforation
clear wax with drops

8

presbycusis

gradual hearing loss with age
higher tones affected more/ first

9

3 sources for balance

proprioceptive system
visual system
vestibular system

10

vestibular system

inner ear
filled with liquid
2 parts: semicircular canals & otolith

11

vestibular system: semicircular canals

3 canals at right angles to each other (orthogonal)
measure angular accelerations(roll, yaw, pitch)
small hairs detect movement and convert to electrical impulses which are sent to vestibular nerve

12

vestibular system: otolith

uricle and saccule
measure linear acceleration
uricle measures horizontal acceleration
saccule measure vertical acceleration
also liquid filled
has hairs with chalk on the end(ear rocks) that convert movement to electrical impulses that are sent to vestibular nerve

13

cerebellum

area of the brain for balance