ear and hearing

Question 1

function of the outer ear

Answer 1

funnel sounds into ear canal for amplification into inner ear

Question 2

pina

Answer 2

acts in directing sound further into the ear

Question 3

blind ending tube

Answer 3

closed by the tympanic membrane with funnel at open end

Question 4

resonant frequency

Answer 4

natural frequency of vibration determined by the physical parameters of the vibrating object

Question 5

what is the middle ear connected to

Answer 5

upper respiratory tract via Eustachian tube

Question 6

function of eustachian tube

Answer 6

equalisation of pressure in ears

Question 7

oval window

Answer 7

membrane covered opening that leads to vestibule of inner ear

Question 8

round window

Answer 8

vibrates with opposite phase to vibrations entering inner ear through oval window

Question 9

what does the middle ear do

Answer 9

transmits vibrational waves from the tympanic membrane into electrical impulses

Question 10

why is the middle ear succeptible to infections

Answer 10

connected to URT

Question 11

how is the tympanic membranee connected to the oval window

Answer 11

three bones connected by synovial joints

Question 12

what are the three bones

Answer 12

malleus
incus
stapes

Question 13

how to the bones transmit sound

Answer 13

physically move to transmit vibrations from the tympanic membrane to oval window to produce a nerve impulse

Question 14

where does amplification occur

Answer 14

oval window

Question 15

muscles found in the middle ear

Answer 15

tensor malleus

stapedius

Question 16

what is build up of mucus in middle ear called

Answer 16

otitis media

Question 17

what can chronic forms of otitis media lead to

Answer 17

conductive earring loss

Question 18

what is in the inner ear

Answer 18

cochlea

Question 19

what is the cochlea

Answer 19

fluid filler tube coiled

associated with auditory nerve

Question 20

what are involved in balance

Answer 20

semi circular ducts

Question 21

what structure transduces the vibrational energy from sound to action potentail

Answer 21

organ of corti (contains hair cells which have sterocilla)

Question 22

organ of corti

Answer 22

has two types of hair cells (inner and outer)
found on the bacillar membrane
stimulates influx of potassium into hair cells to generate AP

Question 23

bacillary membrane

Answer 23

becomes wider from the base to apex
narrow for high frequency
wide for low frequency
between ST and SM

Question 24

how are sound frequencies recieved

Answer 24

vibration at a point on the basilar membrane transferred to hair cells
vibrations picked up by stereo cilia

Question 25

what are found within sterocilia

Answer 25

potassium channels for depolarisation when bent

Question 26

where is the auditory cotex

Answer 26

temporal lobe

Question 27

what causes the generaation of action potentials

Answer 27

to and fro of hair cells by the tectorial memrbane

Question 28

how is the auditory cortex arranged

Answer 28

tonotopically

Question 29

4 types of hearing loss

Answer 29

auditory processing disorders
conduct hearing loss
sensorineural hearing loss
mixed hearing loss

Question 30

what causes auditory processing disorders

Answer 30

brain unable to process information contained in sound from cochlea

Question 31

cause of conductive heading loss

Answer 31

problem with outer and middle ear interferes passing sound to inner ear

Question 32

sensorineural hearing loss

Answer 32

cochlea or auditory nerve unable to accurately send electrical information to the brain

Question 33

mixed hearing loss

Answer 33

conductive and sensorineural hearing loss

Question 34

arrangement of the coclea

Answer 34

scala vestiboli - top
scala media - middle
scala tympani - bottom

Question 35

where is the organ of corti found

Answer 35

in the scala media on the bacillar membrane

Question 36

how is sound transmitted in the inner ear

steps

Answer 36

movement of oval window leads to movement of fluid
movement of fluid in waves causes bacillar membrane conduct waves (different sections relate to different frequencies/sounds)
waves of the bacillary membrane leads to movement of the inner or outer hair cells on the organ of corti (attached to the bacillary membrane)
the hair cells have steriocillla which then move, leads to action potentials due to K+ influx