Vestibular B6

Question 1

3 semicircular canals, what are they?

Answer 1

anterior, posterior, horizontal

Question 2

3 semicircular canals connect to the _______

Answer 2

utricle

Question 3

Sensory receptors of the semicircular canals reside in the ________ at the base of each ampulla.

Answer 3

cupula

Question 4

The _______ organs are located in the utricle and saccule.

Answer 4

otolith

Question 5

Each canal ends with a single prominent enlargement, the _________.

Answer 5

Ampulla

Question 6

The semicircular canals transduce rotational head movements called _____________.

Answer 6

Angular acceleration

Question 7

Sensory receptor cells in the vestibular system, like those in the auditory system, are called __________ because of the _________ that project from the apical surface of the cell

Answer 7

Hair cells

stereocilia

Question 8

When fluid comes around canal what happens?

Answer 8

Cupula moves and is pushed to one side or another, this displaces the stereocilia

Question 9

Rotational head movements produce ________________ that cause the endolymph in the membranous ducts to be displaced in opposite direction relative to head movement.

Answer 9

Angular accelerations

Question 10

Stereocilia are arranged from shortest to tallest, tallest one is called the ____________.

Answer 10

kinocilium

Question 11

Movement of stereocilia toward the kinocilium causes the hair cells to ________.

Answer 11

Depolarize which results in an increased rate of firing in vestibular afferent fibers. (how we sense movement of our head)

Question 12

If stereocilia are deflected away from the kinocilium, it causes the hair cells to ___________

Answer 12

Hypepolarize, and afferent firing rate decreases. (how we sense movment of our head)

Question 13

Head turn to left, what happens?

Answer 13

Left horizontal canal is activated

Question 14

Head turn to right what happens?

Answer 14

Right horizontal canal is activated

Question 15

If you turn your head to the left, which way does lymph flow and which sides are excited, and inhibited? know it for right head turn too. (just opposite)

Answer 15

(slide 17) Lymph flows to right, Excitation of left

Inhibition on right

Question 16

Head turn to right, excites the ____________ and inhibits the ___________.

Answer 16

Right horizontal canal

Left horizontal canal

Question 17

Receptor cells in each vestibular organ are innervated by ______________ that join with cochlea to comprise the Vestibulocochlear CN8)

Answer 17

primary afferent fibers

Question 18

The cell bodies of these bipolar vestibular afferent neurons are in the _________ ganglion, which lies in the internal acoustic meatus.

Answer 18

vestibular

Question 19

The central processes of these bipolar cells enter the brainstem and terminate in the ____________ .

Answer 19

IPSILATERAL vestibular nuclei

Question 20

The vestibular system influences _______ and reflexive _________ adjustments of the head and body through 2 main descending tracts.

Answer 20

muscle tone

postural

Question 21

Medial vestibulocochlear (Medial longitudinal Fasciculus, MLF), a long tract that runs through the entire brainstem. Descends in ___________ and __________.

Answer 21

Medial medulla
Medial spinal cord
(BILATERAL)

Question 22

MLF ends in ____________ and does what?

Answer 22

Cervical cord.
Head and neck movment
Medial vetstibulospinal tract (MVST)

Question 23

The Lateral vestibulospinal tract courses ___________ through the lateral medulla in a deep position. Synapses where? Function?

Answer 23

IPSILATERAL
Synapses LMN in ventral horn
Stabilize the center of gravity and preserve upright posture.

Question 24

Non-specific term that generally means a spatial disorientation that may or may not involve feelings of movement.

Answer 24

Dizziness and Vertigo

Question 25

Patient experiences sensation of spinning while things in environment are not moving.

Answer 25

Subjective vertigo

Question 26

Sensation is one of the environment is spinning and the patient is not moving.

Answer 26

Objective vertigo

Question 27

Disease involved with an increase of endolymph volume. Severe vertigo, positional nystagmus, nausea

Answer 27

Meniere’s disease

Question 28

One of the most common vestibular disorders observed clinically is what? Brief episodes of vertigo, that coincide with particular changes in body position.

Answer 28

Benign Paroxysmal Positional Vertigo

Question 29

With a tumor on the vestibulocochlear nerve on the right side, the patient will sense their head turning to which side when stationary?

Answer 29

Left

Question 30

Patients often present with severe vertigo, nausea, and vomiting yet have no accompanying hearing loss or CNS abnormalities.

Answer 30

Vestibular Neuritis

Question 31

Can impair or abolish firing rates. Normal function on contralateral side will lead to sensation of head/ body movement toward the intact side.

Answer 31

Unilateral CNS damage in vestibular nuclei