The Vestibular System

Question 1

Tells us which way is up and where we are going

Answer 1

Vestibular system

Question 2

Vestibulospinal and cervicospinal reflexes act to maintain

Answer 2

Posture

Question 3

Controls reflexive eye movements with pathways that involve the cerebellum and the oculomotor nuclei

Answer 3

Vestibular System

Question 4

Keep the eyes still when the head moves

Answer 4

Vestibulo-ocular reflexes

Question 5

Enable the skeletomotor system to compensate for head movements

Answer 5

Vestibulospinal reflexes

Question 6

The vestibular system detects which two forms of acceleration?

Answer 6

1. ) Linear

2. ) Angular

Question 7

Vestibular-Cerebellar control of blood pressure and Panic Disorders

Answer 7

SIDS

Question 8

Age related decreases in vestibular system functions

Answer 8

Presbystasis

Question 9

We have a 40% loss of sensory hair cells by the

Answer 9

9th decade

Question 10

By age 60, what percentage of patients report vertigo and dizziness?

Answer 10

30%

Question 11

Relate to the position of the head and are mediated primarily by the otolithic organs

Answer 11

Static Functions of Vestibular System

Question 12

Are associated with detecting head movements

Answer 12

Dynamic functions of the vestibular system

Question 13

Angular accelerations are detected by the

Answer 13

Semicircular canals

Question 14

Linear accelerations are monitored by the

Answer 14

Otolithic organs

Question 15

Function in pairs

Answer 15

Semicircular canals

Question 16

Specialized regions of the vestibular labrynth contain

Answer 16

Receptors (Hair Cells)

Question 17

Semicircular canals are made up of an

Answer 17

Ampulla and cupula

Question 18

Contain the ampullary crest a thickened epithelium populated by hair cells

Answer 18

Ampullae

Question 19

A gelatinous mass that covers the ampullary crest

Answer 19

Cupula

Question 20

The ampullae of the semicircular canals are designed to detect

Answer 20

Angular acceleration

Question 21

Bending of the sterocilia towards the kinocilium

Answer 21

Depolarization

Question 22

Bending of the stereocilia away from the kinocilium

Answer 22

Hyperpolarization

Question 23

What are the two ampullary crests of the semicircular canals

Answer 23

1. ) Horizontal canals

2. ) Vertical canals

Question 24

In the horizontal canals, the kinocilium faces the

Answer 24

Utricle

Question 25

In the vertical canals, the kinocilium faces

Answer 25

Away from the utricle

Question 26

Due to the VOR, if the head turns right, the eyes roll

Answer 26

Left

Question 27

The otolithic organs contian the

Answer 27

Utricule and Saccule

Question 28

Contains hair cells oriented in the horizontal plane

Answer 28

Macula of utricle

Question 29

Covered with a gelatinous material with calcium cabonate (otoconia)

Answer 29

Utricle

Question 30

Tilting of the head results in bending of the sterocilia within the

Answer 30

Utricle

Question 31

The utricle responds best to

Answer 31

Linear acceleration in the horizontal plane

Question 32

The macula of the saccule is oriented in the

Answer 32

Vertical plane

Question 33

Responds best to linear acceleration in the saggital or vertical plane

Answer 33

Saccule

Question 34

Detects tilt forwards of backwards

Answer 34

Macula of utricle

Question 35

Each direction of tilt produces a different pattern of depolarization and afferent stimulation of the

Answer 35

Utricle and saccule

Question 36

The vestibular nerve joins the cochlear nerve to form the

Answer 36

Vestibulocochlear nerve (CN VIII)

Question 37

Most vestibulocerebellar fibers come from the

Answer 37

Superior and medial vestibular nuclei

Question 38

Principal pathway by which otolithic organs can regulate extensors

Answer 38

Lateral vestibulospinal tract

Question 39

Mainly cervical and functions in vestibulo-cervical reflexes

Answer 39

Medial Vestibulospinal Tract

Question 40

Bilateral projections, mainly arise from the medial vestibular nucleus

Answer 40

Ventroposterolateral (VPL) Pars Oralis

Question 41

Fills the membranous labrynth

Answer 41

Endolymph

Question 42

Surrounds the membranous labrynth

Answer 42

Perilymph

Question 43

Endolymph is rich in

Answer 43

K+

Question 44

Is low in K+

Answer 44

Perilymph

Question 45

Overproduction of endolymph results in

Answer 45

Ménière's Disease

Question 46

Benign Schwann cell tumors -Usually arise from the vestibular portion of the nerve

Answer 46

Acoustic Neuromas

Question 47

90% of acoustic neuromas are

Answer 47

Unilateral

Question 48

5% of acoustic neuromas are -Autosomal dominant

Answer 48

Bilateral inherited neurofibromatosis type II

Question 49

Involuntary rhythmic movements of the eyes, consisting of a rapid movement in one direction (=saccade) and a slow movement in the opposite direction

Answer 49

Nystagmus

Question 50

Nystagmus is typically is to the side

Answer 50

Contralateral to dysfunctional vestibular apparatus

Question 51

Caused by otoconia detaching from the otolithic membrane of the utricle and getting stuck in a semicircular canal

Answer 51

Benign Paroxysmal Positional Vertigo (BPPV)

Question 52

Then, head movements will cause the otoconia to move and stimulate the

Answer 52

Cupula of semicircular canal

Question 53

Irrigating the external auditory meatus with warm or cold water sets up convection currents in the endolymph which displace the crista ampullaris

Answer 53

Caloric Test

Question 54

The nystagmus in the caloric test is

Answer 54

Towards warm water and away from cold water

Question 55

To test the horizontal canals with the caloric test, simply tilt the patients head back 60 degrees, bringing them to a

Answer 55

Vertical position

Question 56

A patient with a dysfunctional labyrinth or nerve will not respond to

Answer 56

Caloric Stimulation

Question 57

A patient with a dysfunctional labyrinth or nerve will not respond to caloric stimulation. We classify this as

Answer 57

Canal paresis

Question 58

When, with the eyes closed the patient drifts to the side of the dysfunctional vestibular apparatus or nerve

Answer 58

Past pointing

Question 59

If there is vestibular dysfunction, a patient who is parching in place with eyes closed will

Answer 59

Turn or fall to the dysfunctional side

Question 60

You should have the patient gaze no more than 30 degrees from front. If there is a problem, the nystagmus is contralateral to the dysfunctional side

Answer 60

Gaze nystagmus

Question 61

With gaze nystagmus, the patient will have nystagmus on the

Answer 61

Contralateral side

Question 62

May be tested with the Nylen-Bárány maneuver

Answer 62

Positional nystagmus

Question 63

With positional nystagmus, the nystagmus is induced by particular head positions. These patients are particularly troubled by

Answer 63

Vertigo

Question 64

Control of posture; vestibulo spinal reflexes

Answer 64

Lateral Vestibular Nucleus

Question 65

Integration of inputs from the vestibular labyrinth and the cerebellum

Answer 65

Inferior vestibular nucleus