The Ear

Question 1

What substances are in the inner, middle, outer ear respectively?

Answer 1

Fluid
Air
Air

Question 2

Which 2 structures make us the outer ear?

Answer 2

Pinna

Auditory canal

Question 3

Function of the pinna?

Answer 3

Cartilaginous flap

Direct sound waves to opening

Question 4

Function of auditory canal?

Answer 4

Passes through bone to eardrum

Conducts sound waves from pinna to eardrum

Question 5

Which 6 structures make up the middle ear?

Answer 5

Tympanum 
Hammer 
Anvil 
Stirrup 
Eustachian tube 
Oval window

Question 6

Function of tympanum?

Answer 6

Thin membrane, cover opening

Vibrates when sound hits

Question 7

Function of hammer?

Answer 7

Malleus

Articulate to transmit

Question 8

Function of anvil?

Answer 8

Ineus

Amplify vibrations to oval window

Question 9

Function of stirrup?

Answer 9

Stapes

Amplify vibrations to oval window

Question 10

Function of Eustachian tube?

Answer 10

Connect middle ear to throat

Equalizes pressure so membranes vibrate freely

Question 11

Function of oval window?

Answer 11

Separate middle and inner ear

Pass vibrations therefore waves in perilymph

Question 12

Which 6 structures make up inner ear?

Answer 12

Bony labyrinth 
Membranous labyrinth 
Scalas 
Membranes 
Organ of corti 
Auditory nerve

Question 13

What is the function of the bony labyrinth?

Answer 13

Temporal Bone

Perilymph fluid

Question 14

Function of membranous labyrinth?

Answer 14

Floats in perilymph

Endolymph fluid

Question 15

Function of scalas?

Answer 15

Middle cholea= scala media (endolymph)
Upper scala vestibuli= lower scala tympani (bony labyrinth)
Lower scala tympani= to round window

Question 16

Function of cochlea membranes?

Answer 16

Roof= vestibular membrane
Floor= basilar membrane
Movement causes waves in endolymph

Question 17

Function of Organ of Corti?

Answer 17

On basilar membrane covered by tectorial membrane
Hairs embedded in gelatinous tectorial membrane
Hairs make impulses that convert mechanical stimuli to nerve impulses

Question 18

Function of auditory nerve?

Answer 18

Nerve impulses travel to temporal lobe

Question 19

Which 3 structures make up the vestibular apparatus?

Answer 19

Uticulus
Sacculus
Semi circular canals

Question 20

Function of Utricullus?

Answer 20

Sacs suspended in perilymph

Question 21

Function of Sacculus?

Answer 21

Maculae = equilibrium receptors
Patches of hair cells
Dendrites leave
Respond to gravity -> utricular macula (gel like)->feels head tilting (otalriths = earstones)

Question 22

Functions of semi circular canals?

Answer 22

Pull on sensory hairs to keep CNS informed on position, movements and balance

Question 23

What are the 3 semi circular canals?

Answer 23

Anterial
Laterial
Posterial

Question 24

What happens when there is an ear infection?

Answer 24

Fluid put pressure on ear drum causing redness and pain
Eustachian closes and puss forms
Virus and bacteria enter tube from throat

Question 25

Causes of deafness?

Answer 25

``` Aging Infections Drugs Noise damage Hereditary ```

Question 26

4 steps of a cochlear implant?

Answer 26

1. Sound processor captures sound - converts to digital code 2. Digitally coded sound moves through coil to implant 3. Implant converts sound to electrical signals - sends to array in cochlea 4. Implant electrodes stimulate cochlea heating nerve fibers - relay sound signals to brain therefore producing hearing sensations