Vestibular Part 2

Question 1

how are the SCC orientated in relation to each other

Answer 1

orthogonal (right angles of each other)

Question 2

pitch

Answer 2

shaking head yes

Question 3

roll

Answer 3

tilting head to the side

Question 4

yaw

Answer 4

shaking head no

Question 5

responsible for detecting head movement

Answer 5

SCC

Question 6

Which SCC detects yaw

Answer 6

horizontal scc

Question 7

which SCC detects pitch

Answer 7

anterior

Question 8

which SCC detects roll

Answer 8

posterior

Question 9

widening of the bony membranous portion of each canal

Answer 9

ampualle

Question 10

what does ampullae house

Answer 10

cristae ampullaris

Question 11

is the cupula sensitive to gravity

Answer 11

no, its density is similar to the endolymph

Question 12

sensitive to motion

Answer 12

cupula

Question 13

sits atop cristae ampullaris and is genatinous membrane to close off the lumen of the canal

Answer 13

cupula

Question 14

Vestibular hair cells are stimulated by movement, ______ and a position relative to gravity ______.

Answer 14

SCC, Otolithic

Question 15

in SCC, deflection of stereocilia toward kinocilium =

Answer 15

depolarization

Question 16

in SCC, deflection of stereocilia away from kinocilia

Answer 16

hyperpolarization

Question 17

head forward, explain signals in utricle and saccule

Answer 17

utricle is laying horizontal so no firing is happening, saccule is laying verticle so the otoconia pull the otolithic membrane and hair cells down, generating signals

Question 18

head backward, explain the utricle and saccule

Answer 18

utricle is now verticle, causing the otoconia to pull the otolithic membrane and hair cells down, generating signals
saccule is horizontal so otoconia has no pull so there are no signals firing

Question 19

if we accelerate in our car, what happens?

Answer 19

the otoconia on the utricle lag behind, activating the hair cells

Question 20

faster car moves

Answer 20

greater the stimulation

Question 21

once the car is at a stable motion, the otoconia and gel catch up resetting it back to resting position

Answer 21

no activation

Question 22

ampullopetal

Answer 22

toward the ampulla

Question 23

ampullofugal

Answer 23

away from the ampulla

Question 24

explain endolymph movement in lateral canal

Answer 24

endolymph movement toward the ampulla (ampullopetal) = excitation
endolymph movement away from the ampulla (ampullofugal) = inhibition

Question 25

explain movement in anterior/posterior canal

Answer 25

endolymph toward ampulla = inhibition
endolymph away from ampulla = excitation

Question 26

For the lateral SCC, ampullopetal movement causes __________ (excitation / inhibition) and ampullofugal movement causes __________ (excitation / inhibition).

Answer 26

excitation
inhibition

Question 27

For the anterior SCC, ampullopetal movement causes __________ (excitation / inhibition) and ampullofugal movement causes __________ (excitation / inhibition).

Answer 27

inhibition
excitation

Question 28

For the posterior SCC, ampullopetal movement causes __________ (excitation / inhibition) and ampullofugal movement causes __________ (excitation / inhibition).

Answer 28

inhibition
excitation

Question 29

A leftward horizontal movement will result in an ________ response from the left labyrinth and a corresponding _______ response from the right labyrinth.

Answer 29

excitatory
inhibitory