Physiology Of Hearing

Question 1

Answer 1

Question 2

Answer 2

Question 3

What is the eardrum known as?

Answer 3

Tympanic membrane

Question 4

Answer 4

Question 5

What is the role of the ossicles?

Answer 5

Rely and amplify information to the cochlea

Question 6

Answer 6

Question 7

What is the role of the cochlea?

Answer 7

An organ where sound waves are converted first into fluid waves, then into chemical signals and finally into action potentials

Question 8

Answer 8

Question 9

How to ear hairs allow sound to be heard?

Answer 9

The movement of basilar and tectorial membranes by sound waves moves cilia on the hair cells and effects neurotransmitter release

Question 10

What allows the AP, what channels?

Answer 10

Potassium and calcium channels

Question 11

Where would we hear high frequency sounds?

Answer 11

Stapes end of the basilar membrane

Question 12

What is conductive deafness?

Answer 12

Wax build up
Blockage of Eustachian tube
Inflammation
Damage to ear drum
Otosclerosis

Question 13

What is sensorineural deafness?

Answer 13

Hair cell damage in organ of corti

Question 14

What are examples of se sensorineural deafness

Answer 14

Trauma
Ageing
Infection
Drugs
Ménière’s disease

Question 15

Do hair cells regenerate in mammals?

Answer 15

No

Question 16

What is nerve deafness?

Answer 16

Damage to the auditory nerve itself

Question 17

What is the movement associated with the part of the canal?

Answer 17

Question 18

What nerve carries info from the vestibular apparatus to the brain?

Answer 18

Vestibular branch of the vestibulocochlear nerve

Question 19

Answer 19

Question 20

How does the cochlea make sound?

Answer 20

Is the organ where sound waves are converted first into fluid waves, then into chemical, signa,s and finally into AP

Question 21

What is the middle canal also called?

Answer 21

Cochlea duct

Question 22

What separates the tympanic canal and the middle canal?

Answer 22

Basilar membrane

Question 23

What membrane separates the middle canal from the vestibular canal?

Answer 23

Reissner’s membrane

Question 24

What membrane sits on top of the hair cells?

Answer 24

Tectorial membrane

Question 25

What do the hair cells sit between?

Answer 25

Basilar membrane and the tectorial membrane

Question 26

What do the stapes vibrate against?

Answer 26

Oval window

Question 27

How do the hair cells move?

Answer 27

The movement of the basilar and tectorial membrane by sound waves moves the cilia on the hair cells, fluid waves made and affects neurotransmitter release

Question 29

What type of receptor are the cilia?

Answer 29

Mechanoreceptors

Question 30

What cells support cilia and hold them in place?

Answer 30

Deiter’s cells

Question 31

How are the cilia arranged?

Answer 31

In rows

Question 32

What connects the cilia?

Answer 32

Tip links

Question 33

What are top links?

Answer 33

Very fine cytoskeleton elements

Question 34

What is the purpose of the cilia being connected by tip links?

Answer 34

The hairs move as one

Question 35

What channels are opened up when the hairs move as one?

Answer 35

Mechano electro transduction channels MET channels Potassium ion channels, positive ions into the cells and a depolarisation

Question 36

What is the synaptic density called?

Answer 36

Synaptic ribbon

Question 37

What is a synaptic ribbon?

Answer 37

Vesicles of neurotransmitter attached to the ribbon

Question 38

How are the vesicles on the ribbon released?

Answer 38

Calcium causes the tethers of the vesicles to be broken Vesicles are released Fuse with the presynaptic membrane Spill into the neurotransmitter into the synaptic cleft

Question 39

Describe sound transmission, 6 stages

Answer 39

1. Sound waves in the air strike the tympanic membrane 2. Sound waves energy is transferred to bk Ds of the middle ear, which vibrate 3. The vibrations are transmitted via the oval window to the fluid within the vestibular duct and create a fluid v Wave within the cochlea 4. The fluid waves push on the flexible membrane of the cochlear duct 5. Sound waves are transmitted to the tympanic duct and dissipated back into air by the movement of round window 6. Deformation of the cochlear duct causes the tectorial membrane to move and activate stereocilia of the hair cells

Question 40

Where do fluid waves get converted back into air waves?

Answer 40

In the inner ear

Question 41

What membrane is moving during hearing?

Answer 41

Basilar membrane, this moves the cilia

Question 42

What one is resting, depolarisation and hyperpolarisation?

Answer 42

1. Resting 2. Depolarisation 3. Inhibition (less AP)

Question 43

What happens as you move down the basilar membrane?

Answer 43

Broadens out and becomes thinner

Question 44

Where do we hear high frequency sounds?

Answer 44

More towards the stapes end

Question 45

Where do we hear lower frequency sound?

Answer 45

At the more distal end Helicotrema

Question 46

Answer 46

A = eardrum B = stapes C = basilar membrane D = Helicotrema

Question 47

Describe the area where we hear high frequency sound?

Answer 47

Stiff region near round window

Question 48

Describe the area where we hear low frequency sound?

Answer 48

Flexible region near helicotrema

Question 49

How is balance maintained?

Answer 49

Maintained through the hair cells in the fluid filled vestibular apparatus and the hair cells in the semicircular canals of the inner ear

Question 50

What are the 2 components of equilibrium?

Answer 50

Dynamic component Static component

Question 51

What is the dynamic component of equilibrium?

Answer 51

Sensing rotational movement of the head

Question 52

What is the static component of equilibrium?

Answer 52

Senses head displacement via linear acceleration and the associated gravitational changes

Question 53

What detect rotational movements?

Answer 53

By hair cells found within the ampulla linked to the semicircular canals

Question 54

What detects gravitational changes?

Answer 54

Are detected by the otolith organs found within the maculae at the base of the semicircular canals

Question 55

What are ampullae?

Answer 55

Swelling at the base of the semicircular canals

Question 56

What hair cells do the ampullae contain?

Answer 56

Christae

Question 57

What are found at the base of the semicircular canals?

Answer 57

Maculae

Question 58

Answer 58

Question 59

What is this image showing?

Answer 59

Crista

Question 60

What are these cells?

Answer 60

Hair cell receptors

Question 61

What is surrounding the hair cell receptors here?

Answer 61

Cupula - gelatinous endolymph fluid

Question 62

What happens when you get fluid movement in the endolymph?

Answer 62

Movement of the endolymph pushes on gelatinous cupula and activates the receptor cells

Question 63

What happens to hair movement in the cochlea when you rotate your head?

Answer 63

Head rotation increases firing frequency in canals on one side and reduces it in the other

Question 64

What crystals are found in the macula?

Answer 64

Otoliths

Question 65

What structure is shown here, and what is it involved in?

Answer 65

Macula, involved in gravity forces

Question 66

What structure moves in response to gravitational forces?

Answer 66

Otoliths

Question 67

Where do the 2 branches of the vestibulocochlear nerve go?

Answer 67

1. Cerebellum 2. Vestibular nuclei of medulla

Question 68

What are the 2 pathways of the vestibular nuclei of medulla?

Answer 68

1. Thalamus and then cerebral cortex 2. Somatic motor neurones concerned with eye movements - keep eyes in position