27-Motor8-Vestibular

Question 1

Signals from vestibular apparatus leave in cranial nerve ___:___

Answer 1

VIII, vestibulocochlear

Question 2

Three compartments of vestibular system

Answer 2

• bony labyrinth
• membranous labryinth
• endolymph

Question 3

Vestibule is part of the [bony/membranous] labyrinth

Answer 3

bony

Question 4

Semicircular canals are part of the [bony/membranous] labyrinth

Answer 4

bony

Question 5

Saccule is part of the [bony/membranous] labyrinth

Answer 5

membranous

Question 6

Utricle is part of the [bony/membranous] labyrinth

Answer 6

membranous

Question 7

Semicircular ducts are part of the [bony/membranous] labyrinth

Answer 7

membranous

Question 8

Fluid inside membranous labyrinth

Answer 8

endolymph

Question 9

___ sense head rotation

Answer 9

Semicircular ducts

Question 10

___ sense gravity and linear head motion

Answer 10

Otolithic organs

Question 11

Otolothic organs include ___ and ___

Answer 11

saccule and utricle

Question 12

Primary vestibular afferents terminate in ___

Answer 12

vestibular nuclei

Question 13

Vestibular nuclei integrate inputs from vestibular system with other inputs from (x3)

Answer 13

spinal cord, cerebellum, and visual system

Question 14

Vestibular nuclei project to ___ (x4)

Answer 14

motor structures:
- oculomotor nuclei (oculomotor reflexes)
- reticular system, spinal cord (skeletal reflexes)
- cerebellum (motor coordination, balance)
- thalamus (motor control, position sense)

Question 15

Primary afferents from semicircular ducts terminate primarily in ___ vestibular nuclei

Answer 15

superior and medial

Question 16

Primary afferents from otolithic organs terminate primarily in ___ vestibular nuclei

Answer 16

lateral

Question 17

Information from semicircular ducts primarily affects reflexes that involve ___

Answer 17

gaze

Question 18

Information from otolothic organs primarily affects reflexes that involve ___

Answer 18

anti-gravity (e.g. posture)

Question 19

Function of vestibulocollic reflex

Answer 19

stabilize head position

Question 20

Hair cells:
Deflection toward kinocilium produces [depolarization/hyperpolarization]

Answer 20

ON direction, depolarization

Question 21

Hair cells:
Deflection away from kinocilium produces [depolarization/hyperpolarization]

Answer 21

OFF direction, hyperpolarization

Answer 22

true

Question 23

Hair cells in ampulla are embedded in ___

Answer 23

christa = a ridge of epithelium

Answer 24

true

Question 25

Cupula

Answer 25

gelatinous flap into which stereocilia of hair cells project

Question 26

Head rotation to the left [activates/inhibits] left horizontal semicircular duct

Answer 26

activates

Question 27

Head rotation to the left [activates/inhibits] right horizontal semicircular duct

Answer 27

inhibits

Question 28

Macula

Answer 28

patch of hair cells in otolothic organ

Question 29

Otolithic membrane

Answer 29

gelatinous sheet, attached to surface of macula, contains otoliths

Question 30

Otoliths

Answer 30

calcium carbonate crystals with higher density than endolymph

Question 31

Otolithic membrane [floats/sinks] in endolymph

Answer 31

sinks

Answer 32

false

Answer 33

true

Question 34

VOR

Answer 34

vestibuloocular reflex

Answer 35

true

Question 36

Control pathway in VOR of right eye during leftward head rotation

Answer 36

left horiz duct activated
-> left cranial nerve VIII activated
-> left medial vestibular nucleus activated
-> right abducens nucleus activated
-> right lateral rectus muscle activated
-> right eye rotates right

Question 37

VOR left head rotation:
Left horizontal duct [activated/inhibited]

Answer 37

activated

Question 38

VOR left head rotation:
Left medial vestibular nucleus [activated/inhibited]

Answer 38

activated

Question 39

VOR left head rotation:
Right abducens nucleus [activated/inhibited]

Answer 39

activated

Question 40

VOR left head rotation:
Right eye moves to [left/right]

Answer 40

right