Cortical Control of Movement Lec21 Flashcards Preview

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

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

hand and fingers

2

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

feed-forward

3

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

weight shifts

4

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

motor cortex.

5

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

functionally

6

Proper motor control requires (3)

timing, position, and physical characteristics of body and muscles

7

brainstem centers are involved with basic movements and ___ conrol

postural

8

____ Motor Pathways can be direct or indirect:

Descending

9

Direct descending motor pathway is from cortex straight to ___

LMNs

10

Indirect descending motor pathway synapse on

brainstem interneurons

11

both direct and indirect synapse on the

ventral horn of the spinal cord

12

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

age/ development

13

indirect pathway UMNs --> ___ --> interneurons

anteromedial white matter (rubrospinal and extrapyramidal tracts)

14

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

axial and proximal muscles

15

Long distance interneurons are medial or ventral

medial

16

Long distance interneurons are medial, go to ___ muscles

proximal

17

Short distance interneurons are lateral, go to ___ muscles

distal

18

direct pathway goes to ___ muscles

distal

19

name 4 indirect pathways

1. tectospinal

2. reticulospinal

3. rubrospinal

4. vestibulospinal

20

tectospinal is involved with__ and __

 axial and midline body orientation

21

rubrospinal is involved with___ controls

distal control, mainly arm flexion

22

vestibulospinal modifies

reflexes, central pattern generators

23

which indirect pathways modify reflexes?

vestibulo and reticuno

24

___ pathway modifies antigravity muscles

reticulospinal

25

example of direct pathways

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

26

Most direct corticomotor innervation comes from the___

primary motor cortex (M1)

27

in the cortex Motor units are controlled by___ or ___ cells

Betz cells or other large, non-Betz pyramidal cells

28

Lateral premotor cortex is involved in

selection of motor responses based one xternal cues

29

Medial premotor cortex is involved with

learned sequences, repsonse to intenral cues

30

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

medial premotor cortex

31

pre-sma is invovled with

learning sequencies

32

3 association areas?

1. Pre-SMA: learning sequences

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

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

33

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

association

34

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

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

face is lateral or medial?

lateral

36

lower face has ___ innervation?

unilateral

37

upper face has ___ innervation

bilateral

38

) Individual muscles are represented in ___ cortex locations

multiple (this is convergence)

39

Individual ____ influence multiple motor neuron pools

neurons

40

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

UMN

41

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

Lateral corticospinal tract

42

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

direct brain stimulation

43

Cortical motor neurons can code for (3)

muscle activity, force, or direction.

44

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

direction

45

3 tasks that must be accomplsihed for proper motor control?

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

the motor sysytem is ___ organized

heirarchially

A image thumb
47

lowest levels in motor system heirachry accomplish

Q image thumb

most automatic behaviors

48

highest levels in motor system heirarchy are concerned with

Q image thumb

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

49

motor system is ___ segregated

functionally

50

____ local circuit neurons control more dextrious mvoement

short distance (lateral)

A image thumb
51

definition of cortical motor area

 

has to project to (2)

1. motor neurons in the spinal cord

2. primary motor cortex

52

definition of cortical motor area

can be stimulated at low thresholds to poduce movements of ___

discrete muscle or muscle groups

53

definition of cortical motor area

 

has to display changes in activity related to 

paramters of movement

54

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

within a single motor area

55

microstim. studies showed that cells with simialr targets are ____

not adjacent to one another (fractured somatopy)

56

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

horizontal connections 

57

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 

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

58

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

multiple muscles that it might innervate

A image thumb
59

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

ndividual cortical cell