Vestibular System

Question 1

What are the sensory receptors for the vestibular system?

Answer 1

Hair cells

Question 2

T/F sound pressure waves activate vestibular hair cells

Answer 2

False

Question 3

Where are hair cells located?

Answer 3

ampulla of the semicircular canals (3) and the utricle and saccule of the otoliths (2)

Question 4

What is the blood supply to the inner ear?

Answer 4

the internal auditory artery

(Basilar–> AICA–> internal auditory artery

Question 5

T/F due to their high energy demand, these structure are highly susceptible to ischemia?

Answer 5

True

Question 6

What do the hair cells on the utricle and saccule sense?

Answer 6

linear acceleration and gravity

Question 7

What is the macula?

Answer 7

The sensory epithelium that the hair cells sit in (in the otilith?)

Question 8

What are otoliths?

Answer 8

crystals of calcium carbonate that sit on top of the gelatinous otolithic membrane to add weight (that can bend the hair cells)

Question 9

When you tilt your head back, the hair cells move back/forward.

Answer 9

Back

Question 10

When you acceleration, the hair cells move back/forward.

Answer 10

Back (so opposite)

Question 11

The utricle cells sit in a _____ plane, and are sensitive to ______ motion

Answer 11

horizontal; forward/backward or side to side acceleration and head tilts where the head is not perfectly straight up and down relative to gravity

Question 12

What are car hair cells?

Answer 12

The cells in the macula of the utricle

Question 13

What are elevator hair cells?

Answer 13

Cells in the macula of the saccule

Question 14

The saccule cells sit in a ___ plane, and are sensitive to _____ movement

Answer 14

Vertical; up and down (and forward and backward)

Question 15

At the end of each semicircular canal is a ____, and inside that is a tissue ridge of sensory epithelium called a _______ that is embedded in a gelatinous mass called a _______

Answer 15

ampulla; crista; cupula

Question 16

How do hair cells in the ampullas move?

Answer 16

Fluid moves the cupula which causes activity in the vestibular neuron to increase or decrease

Question 17

When you turn your head to the right, the fluid in the ampulla moves to the ____

Answer 17

left –> this bends the hair cells in the opposite direction

Question 18

Where is the vestibular nuclei?

Answer 18

The pons/medulla junction

Question 19

Vestibular Nerve cell bodies are located in _____

Answer 19

The vestibular (Scarpa’s) ganglion

Question 20

The Vestibular nuclei projects to the ______ for motor correction

Answer 20

Cerebellum

Question 21

The vestibular nuclei project to the _____ for spatial orientation

Answer 21

posteriolateral thalamus

Question 22

The vestibular nuclei project to the ______ for gaze stabilization

Answer 22

extraoccular muscles

Question 23

The vestibular nuclei project to the _____ for stabilization of head and body posture

Answer 23

Spinal cord via vestibulospinal tracts

Question 24

T/F Vestibular nuclei have strong connections across the midline?

Answer 24

True

Question 25

T/F The Vestibular reflexes do NOT work without a cerebellum

Answer 25

False

Question 26

Much of the vestibular input to the cerebellum goes to _______

Answer 26

flocculonodular lobe

Question 27

The projections to the thalamus activate which parts of the cerebral cortex?

Answer 27

Insula, somatosensory cortex, and the PARIETAL OPERCULUM

Question 28

Most of the otolith input acts on the spinal cord via the _______ tract

Answer 28

Lateral vestibulotract

Question 29

The semicircular canal inputs act via the _______ tract

Answer 29

medial vestibulospinal tract

Question 30

The otliths ultimately affect ______ to adjust ______

Answer 30

proximal muscles; body position

Question 31

The semicircular canals ultimately control _____ postion

Answer 31

Head position

Question 32

The semicircular horizontal canals affect rotation in the _____ plane

Answer 32

Horizontal

Question 33

What are the 3 major vestibular reflexes?

Answer 33

Vestibulo-ocular
Vestibulo-cervical
Vestibulo-spinal

Question 34

The left anterior and right posterior (LARP) canal affection rotation where?

Answer 34

The vertical plane skewed 45 degrees anteriorly and to the left

Question 35

the right anterior and left posterior (RALP) semicircular canal cause rotation where?

Answer 35

In the vertical plane skewed 45 degrees anteriorly and to the right

Question 36

The horizontal semicircular canals are in the same plane as the _____ and ____ muscles

Answer 36

Lateral and medial rectus

Question 37

The LARP canals are in the same plane as the ____ and _____ muscles

Answer 37

“vertical” recti (sup and inf) and right obliques

Question 38

The RALP canals are in the same plane as the ____ and ____ muscles

Answer 38

“vertical” recti and left obliques

Question 39

What is caloric testing?

Answer 39

a method for evaluating the integrity of the vestibular apparatus of each ear, independently

Question 40

When you place warm water in someone’s left ear, their eyes will move to the ____

Answer 40

right, but will quickly move back to the left to keep them focused on a target (coWS)

Question 41

Cold water to the right ear results in ____-beating nystagmus

Answer 41

left (COws)

Question 42

A patient with an intact vestibulo-ocular reflex (as determined by caloric testing) must have an intact _______ and that _______ is the real issue

Answer 42

brainstem; diffuse cortical depression