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Flashcards in Cortical Control of Movement Lec21 Deck (59)
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1
Q

A disproportionate area of the motor cortex is devoted to control of the ___ and ___

A

hand and fingers

2
Q

The "indirect pathway" from cortex to spinal cord enables ___ postural adjustments.

A

feed-forward

3
Q

The "indirect pathway" from cortex to spinal cord plays an important role in ___

A

weight shifts

4
Q

Functionally similar and non-adjacent columns are interconnected by interneurons within the____.

A

motor cortex.

5
Q

Cortical areas that plan and initiate motor sequences comprise several ___ distinct but highly interconnected regions.

A

functionally

6
Q

Proper motor control requires (3)

A

timing, position, and physical characteristics of body and muscles

7
Q

brainstem centers are involved with basic movements and ___ conrol

A

postural

8
Q

____ Motor Pathways can be direct or indirect:

A

Descending

9
Q

Direct descending motor pathway is from cortex straight to ___

A

LMNs

10
Q

Indirect descending motor pathway synapse on

A

brainstem interneurons

11
Q

both direct and indirect synapse on the

A

ventral horn of the spinal cord

12
Q

the proportion of direct vs. indirect terminations varies between species and changes with ___

A

age/ development

13
Q

indirect pathway UMNs --> ___ --> interneurons

A

anteromedial white matter (rubrospinal and extrapyramidal tracts)

14
Q

indirect pathway Indirect: brainstem UMNs --> anteromedial white matter (rubrospinal and extrapyramidal tracts) --> interneurons --> ___ muscles

A

axial and proximal muscles

15
Q

Long distance interneurons are medial or ventral

A

medial

16
Q

Long distance interneurons are medial, go to ___ muscles

A

proximal

17
Q

Short distance interneurons are lateral, go to ___ muscles

A

distal

18
Q

direct pathway goes to ___ muscles

A

distal

19
Q

name 4 indirect pathways

A

1. tectospinal

2. reticulospinal

3. rubrospinal

4. vestibulospinal

20
Q

tectospinal is involved with__ and __

A

 axial and midline body orientation

21
Q

rubrospinal is involved with___ controls

A

distal control, mainly arm flexion

22
Q

vestibulospinal modifies

A

reflexes, central pattern generators

23
Q

which indirect pathways modify reflexes?

A

vestibulo and reticuno

24
Q

___ pathway modifies antigravity muscles

A

reticulospinal

25
Q

example of direct pathways

A

Ventral & Lateral Corticospinals (to body), and Corticobulbar (to face)

26
Q

Most direct corticomotor innervation comes from the___

A

primary motor cortex (M1)

27
Q

in the cortex Motor units are controlled by___ or ___ cells

A

Betz cells or other large, non-Betz pyramidal cells

28
Q

Lateral premotor cortex is involved in

A

selection of motor responses based one xternal cues

29
Q

Medial premotor cortex is involved with

A

learned sequences, repsonse to intenral cues

30
Q

supplementary mtoor area and the cingulate motor area are found in the

A

medial premotor cortex

31
Q

pre-sma is invovled with

A

learning sequencies

32
Q

3 association areas?

A

1. Pre-SMA: learning sequences

2. Parietal and Temporal cortex - Dorsal pathway - Ventral pathway

3. Prefrontal cortex: decision making, working memory, monitoring outcomes

33
Q

____ areas are not “cortical motor areas” even though they’re in the cortex.

A

association

34
Q

Technically, a “cortical motor area”... (4)

A

1. projects from M1 to motor neurons in the spinal cord, either directly or indirectly

2. contains Betz or Betz-like cells that project from layer V;

3.  can be stimulated to produce movements of discrete muscles or muscle groups;

4. displays changes in activity related to parameters of movement.

35
Q

face is lateral or medial?

A

lateral

36
Q

lower face has ___ innervation?

A

unilateral

37
Q

upper face has ___ innervation

A

bilateral

38
Q

) Individual muscles are represented in ___ cortex locations

A

multiple (this is convergence)

39
Q

Individual ____ influence multiple motor neuron pools

A

neurons

40
Q

all the LMNs of a motor neuron pool synapse with the same ___

A

UMN

41
Q

____ lesion in monkey = difficulty getting food from the tube.

A

Lateral corticospinal tract

42
Q

For epilepsy, can map motor cortex via __, then resect “hot” regions or make sub-pial incisions to preserve motor function

A

direct brain stimulation

43
Q

Cortical motor neurons can code for (3)

A

muscle activity, force, or direction.

44
Q

50% of M1 neurons have “movement-like activity”: neuron fires based on which _____ the hand is moving, regardless of which muscles are being used

A

direction

45
Q

3 tasks that must be accomplsihed for proper motor control?

A

1. motor system must produced ACCURATELY TIMED COMMANDS to muscle groups

2. motor system must take into account CURRENT POSITION OF BODY and DISTRIBUTION OF MUSCLE MASS

3. motor system must take into account/compensate for the PHSYCIAL CHARACTERISTICS OF THE BODY AND MUSCLES

46
Q

the motor sysytem is ___ organized

A

heirarchially

47
Q

lowest levels in motor system heirachry accomplish

A

most automatic behaviors

48
Q

highest levels in motor system heirarchy are concerned with

A

complex planning and selection (at the expense of time!)

49
Q

motor system is ___ segregated

A

functionally

50
Q

____ local circuit neurons control more dextrious mvoement

A

short distance (lateral)

51
Q

definition of cortical motor area

 

has to project to (2)

A

1. motor neurons in the spinal cord

2. primary motor cortex

52
Q

definition of cortical motor area

can be stimulated at low thresholds to poduce movements of ___

A

discrete muscle or muscle groups

53
Q

definition of cortical motor area

 

has to display changes in activity related to 

A

paramters of movement

54
Q

microstim. studies showed there are mutliple representations of each body part even

A

within a single motor area

55
Q

microstim. studies showed that cells with simialr targets are ____

A

not adjacent to one another (fractured somatopy)

56
Q

microstim. studies showed columns of functionally related neurons are connected by

A

horizontal connections 

57
Q

METHOD FOR SPIKE TRIGGERED AVERAGING:1) Record from a single upper motor neuron (#1) and a muscle whose lower motor neuron

(#2) may be influenced by it
2) Average EMG from cell #2’s muscle for brief time after each spike (discharge) of cell #1
3) If cell #1 synapses with cell #2, there will 

A

be a change in EMG (Increase=Excitatory, Decrease=Inhibitory)

58
Q

 SPIKE TRIGGERED AVERAGING allows you to to establish connectivity maps between 1 cortical motor neuron and ___

A

multiple muscles that it might innervate

59
Q

if you record from an i___, there is a preferred
direction of movement 

A

ndividual cortical cell