vestibular system

Question 1

what does the vestibular system do

Answer 1

maintain balance posture and spatial awareness

Question 2

which 3 receptor systems are integrated by the vestibular system

Answer 2

eyes
general proprioceptive and cutaneous receptors
vestibular apparatus

Question 3

where is the vestibular apparatus

Answer 3

inner ear

Question 4

2 parts of the labyrinth

Answer 4

vestibular part
auditory part

Question 5

what is the fluid inside the labyrinth

Answer 5

endolymph

Question 6

what fluid bathes the labyrinth

Answer 6

perilymph

Question 7

difference in potassium and sodium concentration in the endolymph and perilymph

Answer 7

endo - high K, low Na
peri - low K, high Na

Question 8

what connects the vestibular part and auditory part of the labyrinth

Answer 8

ductus reuniens

Question 9

are the utricle, saccule, semicircular canals, ampullae, and cochlear in the auditory or vestibular part of the labyrinth

Answer 9

vestibular -utricle, saccule, ampullae, and semicircular canals
auditory - cochlear

Question 10

how many semicircular canals are there

Answer 10

3

Question 11

what are the otolithic organs

Answer 11

utricle and saccule

Question 12

what is the tallest stereocilium on a vestibular hair cell called

Answer 12

kinocilium

Question 13

which cranial nerve do vestibular hair cells synapse to

Answer 13

CN VIII

Question 14

what happens when the stereocilia on a hair cell are bent

Answer 14

hair cell hyperpolarised or depolarised

Question 15

which NT is released at the synapse between hair cells and CNVIII

Answer 15

Glutamate

Question 16

which part of the vesibular apparatus has hair cells surrounded by a gelatinous cupula

Answer 16

Ampullae of semicircular ducts

Question 17

what are hair cells in the semicircular canals sensitive to

Answer 17

Movement
head rotation
acceleration/deceleration
angular acceleration/rotation
Complementary bilateral signalling

Question 18

what do otoliths in the utricular and saccular macula detect

Answer 18

linear acceleration
head tilt
Gravity

Question 19

what provides 3d representation of the direction of linear force

Answer 19

hair cells of utricles and saccules

Question 20

what divides the macula

Answer 20

striola

Question 21

are hair cells in the utricles and saccules polarised towards or away from the striola

Answer 21

utricles - towards
saccules - away

Question 22

what are hair cells in the saccule and utricle sensitive to

Answer 22

gravity
head tilt
linear acceleration

Question 23

nystagmus

Answer 23

initial slow rotation of the eyes followed by compensatory flick back

Question 24

which reflex dysfunction causes nystagmus

Answer 24

vestibulo-occular reflex

Question 25

is the direction of nystagmus defined by the slow or fast component

Answer 25

fast

Question 26

does nystagmus move towards or away from the affected side

Answer 26

fast part away from affected side

Question 27

vestibular lesion symptoms

Answer 27

nystagmus vertigo vomiting dizziness balance problems

Question 28

vestibular lesion symptom treatment

Answer 28

antiemetics antihistamines benzodiazepines

Question 29

why does the caloric reflex test cause eye movement

Answer 29

water heats semicircular canal -> convection of endolymph -> nerve firing -> body thinks head rotatingf -> eyes move to compensate

Question 30

which parts of the brain produce the fast and slow eye movements in the caloric reflex test

Answer 30

slow - brainstem fast - cortex

Question 31

what does the hallpike manoeuvre test for

Answer 31

benign paroxysmal positional vertigo

Question 32

how is the hallpike manoeuvre done

Answer 32

head lowered to table and turned to one side, repeated on other side if result negative

Question 33

hallpike manoeuvre positive and negative result

Answer 33

positive - dizziness and nystagmus when affected ear pointed to floor negative - no effect

Question 34

which nerves control eye movements

Answer 34

CN III IV VI

Question 35

central control of vestibular function

Answer 35

premotor areas - plan movement area 3a - converge w signals from muscle spindles posterior parietal cortex - converge w visual and somatosensory signals cingulate gyrus - activity associated with pain, attention, motivation, and emotions PIVC - converge w proprioceptive signals

Question 36

What structures does the vestibular complex in the brainstem connect to

Answer 36

Vestibulospinal tract Reticular formation Cerebral cortex Thalamus Superior colliculus Ant and Flocculonodular lobes of cerebellum Fastigial cerebellar nucleus