motor control

Question 1

MN pools

Answer 1

group of LMNs in ventral horn, axons project to a single muscle

Question 2

medial pools innervate?

Answer 2

proximal muscles

Question 3

lateral pools innervate?

Answer 3

distal muscles

Question 4

anterior pools innervate?

Answer 4

extensors

Question 5

posterior pools innervate?

Answer 5

dorsal side innervated flexors

Question 6

Tectospinal tract

Answer 6

movement of head towards sound or moving objects

Question 7

Medial corticospinal tract

Answer 7

control of neck, shoulder, trunk, APAs

Question 8

Medial reticulospinal tract

Answer 8

postural muscles, limb extensors, APAs

Question 9

Medial vestibulospinal tract

Answer 9

bilaterally to neck/upper back

Question 10

lateral vestibulospinal tract

Answer 10

extensors(antigravity)

Question 11

lateral corticospinal tract

Answer 11

goal directed

contralateral fractionation of hand movement

Question 12

rubrospinal tract

Answer 12

contralateral upper limb, gross movement

Question 13

lateral reticulospinal tract

Answer 13

facilitates flexors, inhibits extensors

Question 14

Which 2 tracts originate in the cortex?

Answer 14

Medial corticospinal tract

lateral corticospinal tract (pyramidal)

Question 15

Which 5 tracts arise from the brainstem?

Answer 15

tectospinal tract 
medial reticulospinal tract 
medial/lateral vestibulospinal tract 
rubrospinal tract 
lateral reticuospinal tract

Question 16

What are the 2 motor areas that lie in front of the primary motor cortex?

Answer 16

premotor
and
supplementary motor area

Question 17

The central sulcus lies ___ of the primary motor cortex?

Answer 17

in back

Question 18

What is behind the central sulcus?

Answer 18

primary somatosensory area

Question 19

primary motor cortex?

Answer 19

voluntarily controlled movement

Question 20

premotor area?

Answer 20

very heavily involved in planning visually guided movement

Question 21

SMA?

Answer 21

planning bimanually, sequential internally related movement

Question 22

what is the purpose of 1-3 layers of the cytoarchitectonics?

Answer 22

input and

output: project to other cortical areas for intracortical communication

Question 23

What are corticomotorneurons?

Answer 23

Monosynaptic projections from layer 5 to spinal motor neurons and alpha inhibitory interneurons, which are important for fractionation

Question 24

Why are corticomotorneurons important for fractionation?

Answer 24

They do not stop on the way, making them send the signal faster to the hand.

Question 25

layer 5

Answer 25

pyramidal layer, major output layer, axons of pyramidal cells in this layer create the corticospinal tract also output to subcortical structures and other cortical areas

Question 26

Where does the premotor area receive info from?

Answer 26

Receives info from the PPC and primary somatosensory cortex.

Question 27

PMA (premotor area)

Answer 27

• input from PPC and prefrontal cortex
• signal direction of movement
• very active in planning period
• basic spatial parameters
• fires in response to seeing an object
• other neurons, mirror neurons begin to fire when observing an action
• signaling to MI: here’s the object, here’s the direction
• projection to hand and arm areas to MI
• REACHING, GRASPING system

Question 28

SMA

Answer 28

• input from prefrontal cortex, basal ganglia
• very little input from PPC (
• tuned to INTENTION
• complex, bilateral movements (sequence learning, postural control)
• Selecting and executing actions deemed appropriate or withholding objects.

Question 29

MAIN points from precision grip vs power grip

Answer 29

-precision grip required more neuro activity with miniml muscle activity
-power grip showed more muscle activity than neuro activity.
Proving that the primary motor cortex and muscle activation do not have a direct relationship.
The primary motor cortex represents functional tasks.

Question 30

Explain the use of force and direction and how the MI works

Answer 30

• There are horizontal connections through the primary motor cortex that will have synergistic movement and force/direction.
• THE MI codes for force and direction