Auditory and Vestibular Pathways

Question 1

What determines loudness/intensity of sound?

Answer 1

amplitude

Question 2

What determines pitch of sound?

Answer 2

frequency

Question 3

what is timbre?

Answer 3

quality of the sound

Question 4

How is sound heard?

Answer 4

air vibration 
eardrum -> ossicles 
vibration spreads to the cochlea 
converted by fluids in the cochlea into electrical impulses through transduction 
sound perceived in the auditory cortex

Question 5

Where is the footplate of the stapes?

Answer 5

the oval window

Question 6

What is impedance matching?

Answer 6

middle ear bones overcome sound loss by increasing sound pressure

Question 7

How is sound amplified in the middle ear?

Answer 7

area ratio of the ear drum to footplate
lever action of ossicles
buckling of ear drum

Question 8

What is important about the effect of sound on the basilar membrane?

Answer 8

the width and flexibility of the basilar membrane determines the distance a particular frequency travels - tonotopic organisation

Question 9

High pitch distances travel far - T/F?

Answer 9

False

Question 10

What are the hair cells in the organ of corti called?

Answer 10

stereocilia

Question 11

How are stereocilia arranged?

Answer 11

in height order - deflection causes depolarisation/hyperpolarisaion and release of neurotransmitters - neural energy transferred to the brain

Question 12

Why are the tips of hair cells linked?

Answer 12

connect transaction channels

Question 13

Which signals do inner hair cells deal with?

Answer 13

afferent

Question 14

Which signals to outer hair cells deal with?

Answer 14

efferent

Question 15

What is the basis of tonotopy?

Answer 15

different frequencies of sound waves activate hair cells maximally at different locations

Question 16

What is a simplistic pathway of sound perception?

Answer 16

cochlea
brainstem
cortex

Question 17

What does the vestibular system provide for the brain?

Answer 17

information concerning gravity, rotation and acceleration

Question 18

Which organs sense head angular acceleration? (head rotation)

Answer 18

semicircular canals

Question 19

Which organs sense head linear acceleration?

Answer 19

saccule and utricle

Question 20

What are the otolith organs?

Answer 20

utricle and saccule

Question 21

What is the pathway of vestibular function?

Answer 21

peripheral sensory apparatus
central processing system
motor output system

Question 22

What force deforms the hair cells in the labyrinth?

Answer 22

acceleration/gravity

Question 23

What is the function of the semicircular canals?

Answer 23

detect head movements via rotational acceleration

Question 24

What is the ampulla?

Answer 24

bulge in the canal where hair cells are located

Question 25

What effect does movement have on the cilia?

Answer 25

movement causes fluid to circulate and displace the cupula

Question 26

Why are the semicircular canals arranged in such a way?

Answer 26

to cover all planes of movement

Question 27

What movement is sensed by otolith organs?

Answer 27

linear acceleration and gravity

Question 28

What are otoconia made of?

Answer 28

calcium carbonate

Question 29

What do striola do?

Answer 29

organise otoconia into narrow trenches in the otolith organs

Question 30

Signals from the vestibular apparatus are constant - T/F?

Answer 30

True

Question 31

What are the three main categories of output from the vestibular system?

Answer 31

orientation
postural control
eye movements

Question 32

What is the function of the vestibulo-ocular reflex?

Answer 32

keeps the eyes still while the head moves in space

Question 33

What si the function of the vestibulo-colic reflex?

Answer 33

keeps the head still in space while you move

Question 34

What is the function of the vestibular spinal reflect?

Answer 34

adjusts posture for rapid changes in position