Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuroantomy > Posture and Balance > Flashcards

Posture and Balance Flashcards

1
Q

what is CoM?

A

point where the
mass of the body is equally distributed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is BoS?

A

area of the body in
contact with the support surfac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is CoP?

A

Center of
distribution of force applied to the
supporting surfac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is postural control?

A

Controlling body position in space
for dual purpose of orientation
and stability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is postural orientation?

A

Ability to maintain an appropriate
position of the whole body with
respect to the environment and
task

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is postural stability?

A

Ability to control centre of mass
(COM) relative to gravity and base
of support (BOS) during
perturbations or motor tasks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the definition of balance?

A

Ability to control the centre of
mass relative to gravity and the
base of support

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the 3 main sources of sensory input to the CNS?

A

vestibular system - 20%
visual system - 10%
Somatosensory system - 70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what makes up the boney labyrinth?

A

Auditory: cochlea
vestibular: otolith organs, semicircular canals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what part of the inner ear allows us to hear?

A

cochlea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the two parts of the otolith organs?

A

utricule and saccule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the fluid that fills the membranous labyrinth called?

A

endolymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the sensory receptors within the membranous labyrinth?

A

hair cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does each semicircular canal contain?

A

an ampulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is contained within each ampulla?

A

a cupula (gelatinous mass)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

where would you find the hair cells within the semicircular canals?

A

within the cupula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what will displace the hair cells within the canals?

A

angular acceleration rotates th egel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how are the hair cells depolarized in the semicircular canals?

A

all hair cells depolarize together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the purpose of the semicircular canals?

A

stabilize vision during head turns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the different semicircular canals?

A

anterior, posterior, horizontal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how are the semicircular canals oriented to each other?

A

Oriented at 90 degrees to
one another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how are the anterior and posterior semicircular canals oriented to midline?

A

Superior and posterior
canals are 45 degrees
from midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how is there a counter balance design to the semicircular canals?

A

Each canal works with a partner on the opposite side

Canals activate more strongly in response to movement in a particular plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what happens to firing when we move our head to a particular side?

A

We increase activity in the semicircular canal on the side we are moving toward and decrease activity the side we are moving away from

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what movement is the horizontal semicircular canal sensitive to?

A

Rotation in the transverse plane ie. head turns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what movement are the anterior/posterior semicircular canals sensitive to?

A

Movement in sagittal plane ie. nodding head

Movement in the coronal plane ie. side- bending

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what happens to the frequency of action potentials in relation to acceleration?

A

Frequency of action potentials increases with higher acceleration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how many utricle and saccules are on each side?

A

One utricle and saccule on each side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

do the saccules or utricules contain a sensory epithelium?

A

both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is the sensory epithelium of a utricule and saccule called?

A

macula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what does the macula contain?

A

hair cells enclosed by a gelatinous mass topped by crystals

32
Q

what is the crystal layer of the sensory epithelium called?

A

otoconia

33
Q

what are the utricules and saccules sensitive to?

A

linear movements and static head tilts

34
Q

what is the macular orientation of the urticule like?

A

more horizontal, meaning it is more responsive to horizontal movement like side bending, lateral displacement

35
Q

what is the macular orientation of the saccule like?

A

more vertical meaning it is more responsive to vertical movement like up-down, forward/backward movement

36
Q

what is the hair cell orientation in the utricule and saccule?

A

they are oriented in different directions, so on opposite sides of each macula, hair cells
are sensitive to opposite motions

37
Q

why are the vestibular pathways special?

A
  1. They are multisensory (receive
    visual and vestibular input)
    * Essential for postural control
    and control of eye movements
  2. Vestibular nuclei provide very
    fast compensatory eye and head
    movements
38
Q

what is the function of the medial longitudinal fasciculus (MLF)?

A

tells the eyes which way
they should move via connections
with cranial nerves

39
Q

what reflex is the medial longitudinal fasciculus involved with?

A

vestibular-ocular reflex (VOR)

40
Q

what is an example of the vestibular-ocular reflex (VOR)?

A

As head turns to right:
Right horizontal semicircular canal is
active; left horizontal semicircular canal
is inhibited

Eye musculature responsible for moving
eyes to left are activated

Eye musculature responsible for moving
eyes to the right are inhibited

41
Q

what is the function of the vestibular-ocular reflex (VOR)?

A

Keep eyes on target while head is moving

42
Q

what is the vestibulospinal tract involved in?

A

the control of postural orientation and stabilit

43
Q

what tracts does the vestibular nuceli give rise to?

A

medial and lateral vestibulospinal tracts

44
Q

where does the medial vestibulospinal tract arise from?

A

medial vestibular nucleus

45
Q

how does the medial vestibulospinal tract descend?

A

bilaterally in spinal cord

46
Q

what does the medial vestibulospinal tract regulate?

A

head/neck position

47
Q

what is the vestibular cervical reflex? (VCR)

A

Moves head in opposite direction
of motion

48
Q

where does the lateral vestibulospinal tract arise from?

A

lateral vestibular nuclei

49
Q

what does the lateral vestibulospinal tract control?

A

proximal extensor muscle tone for
maintenance of posture
* Particularly lower limbs

50
Q

what is the vestibular spinal reflex (VSR)?

A

Body flexes in opposite direction of motion

51
Q

what does the cerebellum provide input to?

A

medial and lateral vestibular
nuclei

52
Q

what does the cerebellum distinguish between?

A

Motions detected by otoliths
and semicircular canals

Active vs passive
movements

53
Q

where does the vestibular cortical system ascend from?

A

bilaterally from vestibular nuclei to the
ventral posterior nucleus of
the Thalamus

54
Q

where does the vestibular cortical system go to

A

Multiple cortical areas
* Parietal cortex and insula

55
Q

what does the vestibular cortical system generate?

A

a head-in-space picture

56
Q

what system is the vestibular system matched to?

A

visual system

57
Q

why does physiological vertigo occur?

A

because there is a conflict between sensory
systems

58
Q

why does pathological vertigo occur?

A

a sudden imbalance of vestibular signals
due to a lesion in the vestibular system

59
Q

what is the most common form of vertigo?

A

Benign Paroxysmal Positional Vertigo
(BPPV)

60
Q

what causes Benign Paroxysmal Positional Vertigo (BPPV)?

A

Displacement of otoconia from
the otoliths into the semicircular
canal

61
Q

what happens when there is a crystal thats gets into the semicircular canals?

A

Signals to the brain that movement
is occurring despite no movement

62
Q

what canal does a displaced crystal typically wind up in?

A

90% of the time, the posterior
canal

63
Q

what is the name of the maneuver to put the crystal back in place?

A

Epley maneuver (uses gravity)

64
Q

what is the feedforward mechanism?

A

anticipatory postural adjustments executed in anticipation of postural instability

65
Q

what is the feedback mechanism?

A

corrective postural control strategies in response to unexpected postural instability

66
Q

what is static/steady state balance?

A

our ability to control our center of mass relative to our base of support in predictable and unchanging environments

67
Q

what is anticipatory/proactive balance?

A

our ability to activate muscles for balance in advance of potentially destabilizing voluntary movements (primarily using feedforward mechanisms)

68
Q

what is reactive balance?

A

our ability to recover our stability after an unexpected perturbation (using feedback machanisms)

69
Q

when is the ankle strategy activated?

A

small perturbations on a firm base of support

70
Q

what does the ankle strategy rely heavily on?

A

somatosensory inputs

71
Q

what muscles are activated first for the ankle strategy?

A

distal muscles

72
Q

when is the hip strategy activated?

A

during larger or faster perturbations or when on compliant surfaces or smaller BoS

73
Q

what does the hip strategy rely heavily on?

A

vestibular and visual inputs

74
Q

what muslces are activated first in the hip strategy?

A

proximal muscles then distal muscles

75
Q

what are some change in support strategies?

A

moving the limbs to change the BoS

shifting from one strategy to another or using a combination of strategies

Neuroantomy (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions