Motor Control 1

Question 1

Motor control is a functional hierarchy with how many levels

Answer 1

3
High
Middle
Low

Question 2

What is present in the high level functional hierarchy and what is its function

Answer 2

Association neocortex
and basal ganglion

Purpose = strategy
(the goal the movement strategy to best achieve this goal)

Question 3

What is present in the middle level functional hierarchy and what is its function

Answer 3

Motor cortex
Cerebellum

Purpose = tactics
(the sequence of spatiotemporal muscle contractions to achieve a goal smoothly and accurately)

Question 4

What is present in the low level functional hierarchy and what is its function

Answer 4

Brain stem and spinal cord

Purpose = activation of motor neurone and interneurone pools to generate goal directed movements

Question 5

What do lateral pathways control

Answer 5

Voluntary movement

Question 6

What do ventromedial pathways control

Answer 6

Posture and locomotion

Question 7

Ventromedial pathways are under what control

Answer 7

Brain stem (nuclei)

Question 8

Lateral pathways are under what control

Answer 8

Direct cortical control

Question 9

What are the two pathways in the spine

Answer 9

Lateral pathway

Ventromedial pathway

Question 10

What are the two lateral pathways that control voluntary movement

Answer 10

Corticospinal tract

Rubrospinal tract

Question 11

What are the four ventromedial pathways that control posture and locomotion

Answer 11

Medullary reiculospinal tract

Pontine reticulospinal tract

Vestibulospinal tract

Tectospinal tract

Question 12

What is the function of the corticospinal tract

Answer 12

Carries fibres from cerebrum & brainstem to skeletal muscles via spinal cord

Question 13

What is the overall route for the tract of the lateral and ventromedial pathways

Answer 13

Descending tracts travel in white matter (because they’re myelinated) then synapse with LMN cell bodies in ventral ramus grey matter of the spinal cord

Question 14

What is the longest tract in the body

Answer 14

The cortospinal tract

Question 15

Where does the Cortospinal tract originate

Answer 15

2/3
Areas 4 and 6 (brodmann) frontal primary motor cortex

1/3 somatosensory cortex

Question 16

Where does the corticospinal decussate (cross over)

Answer 16

At the medulla- spinal cord junction

Question 17

What does decussation of the corticospinal tract result in

Answer 17

Right motor cortex controls left side : left motor cortex controls right side

Question 18

Where does the corticospinal tract axons synapse

Answer 18

ventral horn motor neurones and interneurones to control muscles

Question 19

Where does the rubrospinal tract start

Answer 19

In the red nucleus of the midbrain

Question 20

What symptoms arise due to lessons in CST and RST

Answer 20

fine movements of arms and hands lost

(Can’t move shoulders, elbows, wrist and fingers independently)

Question 21

What occurs if CST has a leison on it own

Answer 21

fine movements of arms and hands is again lost but function repairs after a few months as is taken over by RST

Question 22

What is the function of the vestibulospinal tract

Answer 22

Maintain balance and posture when head moves so stabilizes the Head & Neck

Question 23

What is the function of the Tectospinal tract

Answer 23

Ensures eyes remain stable as the body moves

Question 24

Where does the vestibulospinal tract originate

Answer 24

Vestibular nuclei in the medulla

Question 25

Where does the tectospinal tract originate

Answer 25

Superioir colliculus in the midbrain

Question 26

Where does Pontine and medullary reticulospinal tracts originate

Answer 26

Brainstems reticular formation

Question 27

What is the function of the Pontine and medullary reticulospinal tracts

Answer 27

Use sensory information about balance, body position and vision to reflexly maintain balance and body position

Question 28

What does the pontine and medullary reticulospinal tracts innervate

Answer 28

Trunk and antigravity muscles in limbs

Question 29

What is the pathway of descending motor control

Answer 29

1. Primary motor cortex/pre motor areas 2. Upper motor neurones in the cortex/brainstem 3. white matter of spinal cord as tract pathways 3. Lower motor neurones in the grey matter of spinal cord

Question 30

How are lower motor neurones distributed

Answer 30

Somatotopic -specific relation between particular body regions and corresponding motor areas of the brain

Question 31

Lower motor neurones are located where in the spinal cord

Answer 31

The grey matter

Question 32

Where does the the Lower motor neurones more lateral in the grey matter innervate

Answer 32

Distal limb muscles

Question 33

Where does the the Lower motor neurones more medial in the grey matter innervate

Answer 33

Proximal limb and axial muscles

Question 34

How do white matter tracts differ from lower motor neurones

Answer 34

In origin and function

Question 35

Where is the primary motor cortex (area 4) located

Answer 35

Precentral gyrus

Question 36

Where is the premotor cortex (area 6) located in relevance to primary motor cortex

Answer 36

Anterioventral to the percentile gyrus | closer to the nasal/oral area

Question 37

What areas of the cortex are involved in planing and instructing the voluntary movements

Answer 37

Primary motor cortex (Area 4) Premotor areas/supllementary Area 6 Prefrontal cortex Primary Somatosensory Cortex (Post-central gyrus) Posterior Parietal Cortex (Visual Input) (Area 5&7)

Question 38

What information does the cerebral cortex need to function

Answer 38

where the body is in space where it wants to go and select a plan to get there

Question 39

What is the two areas that make up area 6

Answer 39

Premotor area Supplementary motor area

Question 40

How does supplementary motor area innervate motor units

Answer 40

Directly

Question 41

How does Pre motor area innervate motor units

Answer 41

connects reticulospinal neurones innervating proximal motor units

Question 42

How is the somatotopic motor map not precise

Answer 42

It does not represent upper motor neurones causing individual muscle movements is functional rather than muscle specific

Question 43

What does microsimulation in specific area of primary motor cortex elicit

Answer 43

coordinated movements of hand and mouth or movements that bring hands into central space to inspect/manipulate objects

Question 44

What is the purpose of posterior parietal cortex (areas 5 and 7) in for the cerbral cortex coordination of body movement

Answer 44

To give a mental image of body in space is generated by somatosensory, proprioceptive and visual inputs

Question 45

What is the function of the prefrontal and posterior parietal cortex combined

Answer 45

Decide what movement to make

Question 46

What is the function of area 6 in coordinating body movements

Answer 46

Encodes signals from the axons of prefrontal and parietal cortex and converts into how the actions will be carried out firing the decision making neurones

Question 47

What is the function of area 4 in coordinating body movements

Answer 47

Performs the movement by activating neurones of Corticospinal tract and Rubrospinal tract

Question 48

When do premotor fibres fire action potential in relevance to when movement occurs

Answer 48

1 second before movement occurs

Question 49

What makes the premotor area fire decision making neurones

Answer 49

When movement is made or rehearsed mentally and when watching others perform the movement

Question 50

What is the two overall objective of motor circuits

Answer 50

to plan our movements and allow understanding of the actions/goals of others

Question 51

What may premotor neurones also underpin

Answer 51

emotions and empathy

Question 52

when may premotor neurones be dysfunctional

Answer 52

autism