A&P vestibular Flashcards

1
Q

During a lifetime what percentage of adults experience dizziness

A

40%

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2
Q

What percentage of adults experience dizziness over the age of 60

A

60%

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3
Q

Vestibular rehabilitation includes specific exercises and/or

repositioning maneuvers designed to:

A

decrease dizziness
increase balance function
increase general activity levels

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4
Q

Exercises are designed to

A

promote CNS compensation for vestibular system hypofunction

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5
Q

repositioning maneuvers are used to

A

remove otoconia from semicircularcanals of the inner ear.

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6
Q

What is Anatomical Overview process

A

input (Visual Somatosensory Vestibular) >Processing (Vestibular Nuclear Complex Cerebellum)> output (Vestibular Ocular Reflex Vestibular Spinal Reflex)

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7
Q

Strong Inhibitor

A

of vestibular and somatosensory systems

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8
Q

Neurological Pathways

A

medial longitudinal fasciculus ( MLF)

Dieter’s tract

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9
Q

Visual Cranial Nerve Examination

A

sensory: vision test
motor: smooth pursuit test

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10
Q

Fastest System compared to visual and vestibular systems

A

Neurological Pathway
spinothalamic tract
dorsal column medial lemniscal tract

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11
Q

Sensory Receptor Examination

A

tactile awareness
kinesthetic awareness
proprioceptive awareness

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12
Q

Vestibular System Purpose:

A

head and body orientation

Conflict Resolver: of the 3 systems

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13
Q

Vestibular System Components

A
Vascular Supply: labyrinthine artery
Nerve Supply: CN VIII
Bony Labyrinth: Temporal Bone
Membranous Labyrinth:
Anterior,Posterior,and Horizontal Semicircular Canals(SCC)
Utricle and Saccule (Otoliths)
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14
Q

Bony Labyrinth: contains what

A
Temporal Bone
contains perilymph (high Na:Kratio); supports the membranous labyrinth
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15
Q

MembranousLabyrinth: contains what

A

SCC’s contain endolymph (high K:Na ratio);

Utricle and Saccule (Otoliths) contain endolymph and otoconia (calcium carbonate crystals)

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16
Q

SCC’s have a greatest sensitivity

A

greatest sensitivity to angular motions (rotation, flexion, extension, lateral tilt);

17
Q

Why do SCC’s have a greatest sensitivity have a greatest sensitivity to angular motions

A

orthogonally positioned to one another; function in co-planar pairs (left anterior/right posterior; right anterior/left posterior; left horizontal/right horizontal)

18
Q

Otoliths have a greatest sensitivity to

A

to linear motions (up, down, forward, backward)

19
Q

Why do Otoliths have a greatest sensitivity to to linear motions

A

otoconia (calcium carbonate crystals) giving them mass

20
Q

What is meant by PUSH:

A

The resting neural firing rate of the vestibular nerves are 60-100 pulses per second. When the small steriocilia are “pushed” towards the large kinocilium, that hair cell is depolarized and the frequency of action potential increases.

21
Q

What is meant by PULL:

A

The resting neural firing rate of the vestibular nerves is 60-100 pulses per second. When the small steriocilia are “pulled” away from the large kinocilium, that hair cell is hyperpolarized and the frequency of action potential decreases.

22
Q

What is the PUSH-PULL:

A

Head moves angularly (rotation, flexion, etc…) vestibular nerves on one side of the head are “pushed” and the others are “pulled”. SCC co-planar pairs report to the VNC to determine which direction the head is moving.

23
Q

What neurologically is happening For PUSH PULL

A

Push -Depolarization

Pull -Hyperpolarization

24
Q

If head turns to the right where is the push and pull coming from

A

The RIGHT Pushes or Depolarizes

The LEFT Pulls or Hyperpolarizes

25
Q

Primary Processing: occurs in the

A

vestibular nuclear complex (VNC) which is located between the pons-medulla and cerebellum

26
Q

Adaptive Processing: occurs in the

A

cerebellum and largely has a dampening or inhibitory effect on the vestibular system

27
Q

Vestibular Ocular Reflex (VOR) role is

A

maintains gaze stability while head is moving

28
Q

What is normal VOR

A

gain is = 1; meaning there is an equal but opposite head-to-eye ratio; for every 1 degree the head moves left, the eyes move 1 degree right via the VOR; this provides clear dynamic vision

29
Q

Vestibular Spinal Reflex (VSR)

A

maintains postural stability

30
Q

VOR neural pathways.

A

facillitory (depolarization)

inhibitory (hyperpolarization).

31
Q

If the head is rotating right and the VOR is driving the eyes

A

left, Follow the pathways from the horizontal SCC’s to the extra ocular eye muscles.

32
Q

What are the 3 input systems driving postural stability and dynamic visual acuity

A
Visual System
•	strongest
•	sensory and motor
Somatosensory System
•	fastest
•	tactile/kinesthetic/proprioceptive awareness
Vestibular System
•	conflict resolver of the 3 systems
•	purpose: head and body orientation)
33
Q

2 primary reflexes responsible for postural stability and dynamic visual acuity?

A

Vestibular Ocular Reflex
• Maintains gaze stability while head is moving for clear, dynamic vision
• For every 1 degree that head moves in one direction, the eyes will move 1 degree in the opposite direction
Vestibular Spinal Reflex
• Communicates with muscles for stability to maintain postural stability

34
Q

How do semicircular canals differ from the otoliths

A

They differ from otoliths in that otoliths are the most sensitive to linear motions (up, down, forward, backward) while the semicircular canals are the most sensitive to angular motions (rotation, flexion, extension, lateral tilt).

35
Q

How many semicircular canals are there in the human head

A

There are 6 semicircular canals in total with three in each ear. It is these 6 SCC’s that function in co-planar pairs such as left anterior/right posterior; right anterior/left posterior; left horizontal/right horizontal. They are membranous rather than bone.

36
Q

Which cranial nerves are responsible for eye movement and what are their actions?

A

Cranial nerve III (Oculomotor nerve) – Responsible for eyeball movements up, down, medially, and laterally
Cranial nerve IV (Trochlear nerve) – Responsible for lateral and downward eyeball movements
Cranial nerve VI (Abducens nerve) – Responsible for lateral deviation of the eyeball

CN III = up, down, in
CN IV = down and in (intorsion)
CN VI = out