Vestibular System

Question 1

Name the two functions of this system

Answer 1

1. Response to acceleration and deceleration

2. detects angular and linear movement

Question 2

What is the output of the vestibular system?

Answer 2

Postural stability

Question 3

Semi-circular canals are filled with a fluid called

Answer 3

Endolymph

Question 4

Within the semi-circular canals, within the ampulae there is a ____, which is a bundle of hair receptors

Answer 4

Cupula

Question 5

_________ detect angular movement, changes and rate of head movement and are phasic receptors.

_________ detects linear movement and head tilt/gravity. It responds to sustained slow movements

Answer 5

Semi-circular canals

Utricle

Question 6

______ is the cell body of the Vestibular nerve

Answer 6

Scarpa’s Ganglion

Question 7

Name the two otolith organs

Answer 7

Utricle and Sacula

Question 8

Within the otolith organs there is the _______, where hair cells are located.

Answer 8

Maculae

Question 9

Within the macula, the hair cells are covered by ______, a jello like membrane and rock like structures called_______.

Answer 9

statoconiorum, otoconia

Question 10

T/F There are hair cells inside and outside the macula of the otolith organs.

Answer 10

False. Only in the macula

Question 11

Trace the signal transmission for vestibular input from the macula and the cupula, to the nuclei

Answer 11

1. Hair receptors
2. Scarpa’s Ganglion(the cell body)
3. vestibular part of the vestibularcochlear nerve
4. Vestibular nuclei

Question 12

Where does the superior and medial vestibular nuclei get info from and give input to?

Answer 12

From: Primarily from Canals
To: extraocular muscles (abducens, occulomotor, trochlear); neck and upper trunk

Question 13

Where does the lateral and inferior vestibular nuclei get info from and give input to?

Answer 13

From: Primarily otolith organs
To: output to limbs and trunk

Question 14

T/F There is a reciprocal relationship between vestibular nuclei and the cerebellum

Answer 14

True. Input is efferent and afferent

Question 15

The Lateral vestibular nuclei affect which areas of the body?

Answer 15

Predominate in cervical and lumbosacral regions.

Critical in regulating muscle tone and promoting balance

Question 16

The Medial vestibular nuclei affect which area of the body?

Answer 16

Flexion response???
Project through the medulla (medial longitudinal fasciculus) and end in cervical regions

Important for coordination of head movements in maintenence of equilibrium

Question 17

This reflex produces extension in supine and flexion in prone.

Answer 17

Tonic Labyrinthine Reflex

Question 18

This reflex is needed to allow body to move freely around the head

Answer 18

Labyrinthine head righting

Question 19

Describe tilting reaction

Answer 19

trunk moves against displacement of center of gravity. It is essential for balance.

Question 20

Describe body righting on head

Answer 20

Control of head in relation to body in all positions

Question 21

At what age does standing stability reach adult skill level?

Answer 21

8-12 years

Question 22

When is management of intersensory conflict mature?

Answer 22

15-16 years

Question 23

Which nerves receive ascending input from the vestibular system to the eyes and what does it cause?

Answer 23

1. MLF (medial longitudinal fasciculus) in the medulla —> CN 3, 4, 6 nuclei
2. Vestibulo-ocular reflex (VOR): compensatory to head movement
3. Smooth pursuit: reflexive movements designed to keep image on the fovea of retina.

Question 24

Define/Describe nystagmus

Answer 24

compensatory eye movements during rotation. Work to maintain stable image on retina

Question 25

What are the two phases of nystagmus?

Answer 25

1. Fast phase- saccades to rest position of eye

2. Slow phase–in opposite direction of spin, to maintain stable gaze.

Question 26

Nystagmus is an observable behavior caused by which reflex?

Answer 26

VOR

Vestibulo-ocular reflex

Question 27

Name the 6 projection sites in the brain stem and cortex for vestibular inputs.

Answer 27

1. Thalamus (MGN–>Caudate and VPI–>foot of somatosensory cortex)
2. Somatosensory area 3a.. which responds to proprioceptive, vstibular and moving visual inputs
3. A1, Primary auditory cortex (B41+42)
4. Lateral and inferior nuclei
5. superior and medial nuclei
6. Cerebellum

Question 28

Which two nuclei send pathways through the MLF to the extraocular muscles?

Answer 28

Superior and Medial nuclei

Question 29

What sites are associated with the integration of vstibular inputs with auditory; visual; somatosensory?

Answer 29

Auditory and Vestibular–>Temporal Gyrus (A1) and MGN of thalamus
Proprioception and vestibular–>VPI of thalamus

3a: visual vestibular and proprioceptive input.

Question 30

What are the 4 frequently reported symptoms of a vestibular disorder?

Answer 30

1. dizziness
2. unsteadiness or imbalance when walking
3. vertigo
4. nausea

Question 31

What is the cause of Benign Paroxysmal Positional Vertigo?

Answer 31

Otoconia come loose from utricle and lodge into the ampula of the semi-circular canals

Question 32

What is the tx for BPPV?

Answer 32

Epley maneuver, followed by sleeping in a reclined position and avoiding dizzying maneuvers for a week.

Question 33

______ is an infection or inflammation of the inner ear causing dizziness and loss of balance.

Answer 33

labyrinthitis

Question 34

_______ is an inner ear fluid disorder. It causes episodes of vertigo, fluctuating hearing loss, tinnitus and a fullness sensation

Answer 34

Meniere’s Disease

Question 35

_____ is an exercise approch to decreasing dizziness, increase balance function and increase general activity levels

Answer 35

Vestibular Rehabilitation

Question 36

How can you tell a child has vestibular disorder?

Answer 36

Spontaneous/positional nystagmus

Question 37

T/F Children with ASD demonstrate substatial improvements in engagement and in seat behavior when sitting on a therapy ball in comparison to a carpet square or bench or chair.

Answer 37

True

Schilling & Schwartz,2004