week 3-2

Question 1

what are the sensory receptors in the inner ear

Answer 1

1. Semicircular canals
2. Otoliths

Question 2

what are hair cells

Answer 2

transform mechanical energy into neural activity

Question 3

which one is the kinocilium

Answer 3

tallest strand on the hair cell

Question 4

which one is the sterocilla

Answer 4

all of the smaller ones

Question 5

what happen when the sterocilla are pushed toward the kinocilium

Answer 5

the hair cell depolarizes

Question 6

what happens when kioncillium are pushed into the sterocilla

Answer 6

hyper polarizes

Question 7

what do hair cells respond to

Answer 7

acceleration or gravity that is in line with the hair cell

Question 8

parts of the semi cirular canal

Answer 8

canal and cupula

Question 9

canal

Answer 9

filled with fluid (endolymoh)

Question 10

cupula

Answer 10

houses hair cells in the Crista

Question 11

what does the semi circular canal detect

Answer 11

angular acceleration

Question 12

what does acceleration lead to

Answer 12

increased firing rate

Question 13

what deceleration leads to

Answer 13

hyperpolarization
(decreased firing) in the 8th nerve afferents

Question 14

what happens to firing rate during a constant velocity

Answer 14

the hair cells return to normal leakiness, and the 8th
nerve afferents return to baseline firing rates

Question 15

at rest

Answer 15

• no angular acceleration
• no relative motion between canal and endolymph
• capula not detected
• no perceived angular movement

Question 16

acceleration

Answer 16

-angular clockwise acceleration
-inertia cause endolymph to lag behind
- cupula deflected right
-perceived clockwise movement

Question 17

constant angular motion

Answer 17

-endolymph moving at the same speed as the canal
-no relative motion
-cupla not deflected
- no angular motion

Question 18

deceleration or stopping of motion

Answer 18

-canal stopped
-endolymph movement keeps it moving clockwise
-cupula deflected left perceived
-perceived counterclockwise movement

Question 19

horizontal canal

Answer 19

rotation around the transerves plan
ex yaw NO

Question 20

posterior canal

Answer 20

rotation around the x axis
ex roll shoulder to shoulder

Question 21

anterior canal

Answer 21

pitch YES
around the y axis

Question 22

semi circular canal balance

Answer 22

Balance between left and right excitation and
inhibition that leads to sensation of head
rotation
Head rotation causes opposite
endolymph fluid movement
This causes stereocilia to be pushed
towards kinocilium in the left semicircular
canal = excitation

Question 23

what is the cupula surrounded by

Answer 23

endolymph fluid

Question 24

Otolith organs

Answer 24

Otoliths or otoconia - small calcium carbonate
crystals embedded into gelatinous material

Question 25

where are the small crystal embedded

Answer 25

in this membrane Shearing of the membrane causes the cilia to move

Question 26

when the head tilts or accelerates what deos gravity do

Answer 26

the otoliths to slide, pulling the stereocilia and causing the hair cell to depolarize

Question 27

gravity in the otolith organs

Answer 27

or linear shear due to movement causes stimulation

Question 28

What are the otoliths sensitive to

Answer 28

linear acceleration

Question 29

when we have a motion that is not in line with the sterocilla (perpendicular)

Answer 29

we don,t get any response (no change in any firing rate)

Question 30

what does the firing rate return too

Answer 30

base line firing rate

Question 31

balance on both sides of head

Answer 31

head rotation causes opposite endolymph fluid movement

Question 32

what moves the hair cells

Answer 32

otolithic membrane (gel like substance)

Question 33

utricle ___ linear acceleration

Answer 33

horizontal

Question 34

saccule ___ linear acceleration

Answer 34

vertical

Question 35

why does alcohol make you spin

Answer 35

alcohol blood thinner and decreases bone density

Question 36

alcohol with the endolymph

Answer 36

the density between endolymph and cupula becomes imbalanced less density on cupula, hair cells move artificially

Question 37

BPPV typically occurs in older adults

Answer 37

typically occurs in older adults cause: idiopathic (hit to the head) pathophysiology otolith dislodged into semi circular canal especially when lying down