Brainscape's Knowledge GenomeTM

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


See full index

Neurosciences > Exam2Lec7MotorCortexandVoluntaryMovements > Flashcards

Exam2Lec7MotorCortexandVoluntaryMovements Flashcards

1
Q

What are two areas of the brain that effect the descending systems (UMN)

A
  • basal ganglia
  • cerebellum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the descending systems (UMN)? what are their fxns?

A
  • motor cortex: planning, initiating and directing voluntary movements
  • Brainstem centers: basic movements and postural control
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two pathways that UMN can take? Indirect or direct?

A

Interneruons (indirect)-> reflex coordination
Moter neuron pools(direct)-> LMN

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

What does LMN lead to?

A

skeletal muscles

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

What are two important areas of the brain for motor?

A

Primary motor cortex
premotor cortex
* next to each other

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

what is in gray matter and white matter?

A

gray: cell bodies
white: axons

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

What are the 2 cells in the primary motor cortex

A
  • Betz cells
  • Non-Betz pyramidal neurons (smaller)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where is lower extremity and trunk located on brain? upper extremeity and face?

A

lower: medial
Upper: lateral

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

What is the topographic map for?

A
  • Patterns of facial weakness and their importance for localizing neurological injury
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

For somatotopic organization, what is medial? lateral?

A
  • Medial: Ankle control
  • Lateral: Face, mouth, mastication control areas.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What areas are larger in the somatopic organization? why?

A

Face and fingers representations are larger. There is a greater degree of cortical control of these regions of the body.

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

What areas are larger in the somatopic organization? why?

A

Face and fingers representations are larger. There is a greater degree of cortical control of these regions of the body.

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

Explain the slide of Understanding circuit pathways aids localizing brain injury and causes of patterns of facial weakness

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

The motor cortex controls the spinal cord through both _ and _ pathways

A

direct and indirect

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

Explain the corticospinal and corticobulbar tracts

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

What does the majority of the corticospinal axons do in the lateral corticospinal tract? What about the minority?

A
  • About 90% of the corticospinal axons cross at the pyramidal decussation and travel in the lateral Corticospinal tract
  • About 10% remain in an ipsilateral ventral corticospinal tract and project bilaterally to medial motor neurons serving axial muscles

IN CAUDAL MEDULLA

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

explain the difference of lateral and ventral corticospinal tract when they hit the spinal cord

A
  • lateral (90%): only inn. neurons on the same side of the spinal cord
  • Ventral (10%): sends bilaterally to both sides of the spinal cord
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain the Corticobulbar tract

A

Motor cortex down to middle medulla
* Corticobulbar will synape to reticulat formation then the reticulospinal tract will go down to spinal cord

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

Subcorical motor projections to the spinal cord from?

A
  • Reticular formation
  • Vestibular nuclei (medial and lateral) origin, NOT MOTOR CORTEX
  • “Red” nucleus (Rubrospinal pathway is well known in non-human primates – preliminary
    evidence in human beings).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the feedforward and feedback mechanism of postural control

A
  • Feedforward for “anticipated” postural instability
  • Feedback for unanticipated postural instability
21
Q

Explain the babinski sign and what is it used for? When cannot we not use this?

A
  • The normally when we use a pointed tool up the bottom of the foot, then the toes would curl in (flexion)
  • With babinski sign, the toes will fan out and have a externsor plantar response
  • The Babinski sign can indicate an upper motor neuron lesion constituting damage to the corticospinal tract.
  • Normal in infants until 12-24 months so we cannot use this test
22
Q

Slide 13

A
23
Q

Explain the difference in signs + symptoms in UMN and LMN lesions

A
24
Q

Explain the difference in signs + symptoms in UMN and LMN lesions

A
25
Q

The somatotopic organization of the motor cortex is “ _ ”

A

plastic

26
Q

Representations and neuron properties can be altered with:

A
  • Pathological or traumatic changes -> diease, lose hand, etc
  • Normal experience (e.g., motor-skill learning)
  • Therapy
27
Q

explain the somatoptoic reorganization with experience

A

A rat was trained to a wheel spin task with distal forarm and lever press task with proximal forelimb to get an reward

measure map of the brain and it showed that the brain remapped itself to be better at the tasks
* Wheel spin task requires use of distal forelimb ->Increased space in cortex devoted to distal forelimb after training
* Lever task requires use of proximal forelimb ->increased space devoted in cortex to proximal forelimb after training

28
Q

explain the training induced plasticity of apical spine dnesity in individual C8-projecting cortical motor neurons

A

There is a untrained, active control and skilled grasp (complex)
* skilled has more dendrites and higher density so they can do the task better.
* More dendrites= better neuron fxn

Training and continued experiences can also lead to increased dendritic density of cortical motor neurons. In theory, this could lead to increased efficacy when conducting specific movements.

29
Q

Explain the robot based hand motor therapy after stroke

A

Therapy may also lead to somatotopic re-organization in the brain leading to increased efficacy when conducting specific movements.
HOWEVER, studies indicate that therapy induced reorganization occurs during finely detailed training (i.e. robot grasp therapy) and not with brute movement training (i.e. supination therapy).

30
Q

explain the study with increased sensorimotor cortex activation with therapy, but not with non-practiced supination tasks

A

can lead to somotoplasticity but needs to be fine detail thearpy

31
Q

For corticoal control of mvt, what is the feedforward and feedback for?

A
  • feedforward: Feedforward for “anticipated” postural instability
  • Feedback: Feedback for unanticipated postural instability (sensory)
32
Q

What is sensory feedback adjusted by?

A

“optimal feedback control” using an efferent “copy” of the motor command
* basic knowledge

33
Q
  • What is an efference copy or efferent copy?
  • This copy can be combined with the sensory input that results from?
  • Together with internal models for generating a behavior, efferent copies can serve to enable what?
A
  • An efference copy or efferent copy is an internal copy of an efferent movement-producing signal generated by the motor system.
  • This copy can be combined with the sensory input that results from the movement - enabling a comparison of actual movement with desired movement.
  • Together with internal models for generating a behavior, efferent copies can serve to enable the brain to predict the effects of an action.
34
Q

What does the spike triggered average of EMG: post spike facicilation of muscle activity

A
  • Evidence that single cortical (upper motor) neurons influence muscle activity.
  • Several muscles (and thus several motor neuron pools) may be facilitated by the same cortical (upper motor) neuron
  • Conversely, individual muscles are influenced by many neurons in widely distributed regions of the motor cortex
  • UMN do not touch muscles
35
Q

_ rather than muscles are represented in cortex

A

Movement

36
Q

Primary motor cortex controls what?

A

simple features of movement

37
Q

Micro-stimulation sites evokes what?

A

behaviorally relevant purposeful movements

38
Q

What is important with the “direction of movement is encoded by populations of cortical neurons”

A

neurons in motor cortex have a preferred direction which goes hand and hand with somatopy mapping

39
Q

Upper motor neuron lesion causes weaknees where? What is that due to?

A
  • weakness of inferior facial muscles alone
  • due to compensation
40
Q

Where is weakness with a lower motor neuron lesion? due to what?

A
  • Weakness of inferior +superior facial muscles
  • d/t to lack of compensation at the facial nerve
41
Q

In the wheel spin task, what part of the brain expands? lever pree trask?

A
  • distal forelimb
  • proximal forelimb
42
Q

What do we have in the dorsal pre-motor cortex?

A

reaching and grasping

43
Q

What does reaching require?

A

info about the target location and the proprioceptive info about the limb to be used

44
Q

For reaching, peak velocity of movement is _ to the distance of the target

A

proportionals

45
Q

For grasping, what is it largely determined by?

A

the shape of the target object and NOT its location

46
Q

What happens when the hand moves towards a target object

A

pre-shapes

47
Q

What happens to grip size as it approachs the object

A

increases and then decreases

48
Q

What is the location of mirroe neurons?

A

ventral pre-motex

49
Q

When will the mirror neurons fire and not fire?

A
  • mirror neurons fire: executing a specific motor task and observing another individual performing the same motor task
  • DO NOT: simply prented an object (no motor act) and a motro act is presented without a target object

Neurosciences (28 decks)

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