Motor Control CNS : Cortex + Allied structures

Question 1

Subcortical nuclei send information in which pathways and control what

Answer 1

Medial and ventral spinal pathways and from the medial cerebellum.

Controls Posture ( maintaining a position )

Question 2

Cortical nuclei send information in which pathways and control what

Answer 2

Lateral spinal pathways and from lateral cerebellum.

Innervating Distal limbs for movement

Question 3

What is the Rubrospinal tract , what does It innervate , how does it receive info

Answer 3

Tract that originates in the red nucleus of the medulla.
Receives information from the motor cortex into the red nucleus.Innervates central pattern generators in SC & Cross over midline and innervates distal musculature. Effects posture

Later motor system

Question 4

What happens to the rubrospinal tract if there is a UMN lesion

Answer 4

Tract has a baseline posture and if there is a UMN lesion in which we do not have input from the motor cortex of the brain the limbs will be abnormally flexed and extended in that baseline posture since the rubrospinal tract will still be active but the motor cortex won’t be

Question 5

What is the Reticulospinal tract ? ( what is it composed of , what are its functions ? )

Answer 5

Composed of Pontine and medullary reticular nuclei send info down the spinal cord. Pontine are excitatory for stretch reflexes , medullary are inhibitory to stretch reflex.

Roles: Antigravity and posture functions

Input: cortex, cerebellum

Question 6

If there is a stroke enabling the motor cortex what posture will a patient be in and why

Answer 6

Spastic posture where the arms are flexed and legs are extended due to activity from the reticulospinal and rubrospinal tracts ( Baseline posture )

Question 7

What is the Vestibulospinal tract ( what is it composed of , what are its functions ? )

Answer 7

Composed of vestibule nuclei that serve the position of the head on neck. Receive input from middle ear , cortex and cerebellum.

Role : Neck and posture , maintains balance

Question 8

The Reticulo and vestibulospinal tracts are medial or lateral ?

Answer 8

Medial

Question 9

What areas of the brains re responsible for sophisticated movement and setting posture at the start of a movement

Answer 9

Motor cortex, Premotor area and supplemental motor area

Question 10

Majority of premotor and supplemental areas are located where

Answer 10

Frontal lobe

Question 11

What is the role of wernicke’s and brocca’s

Answer 11

Wernicke : understands language and forms a response e

Brocca: sends signals for movement required to vocalize response

Question 12

What is receptive aphasia

Answer 12

Unable to receive information , problem with wernicke’s

Question 13

What is expressive aphasia

Answer 13

Understand what is being said and having a response but unable to vocalize It , a problem with Brocca’s area

Question 14

What are the pyramidal tracts ( aka lateral corticospinal tracts ) and how do they descend

Answer 14

Cross over high up at pyramids of medulla oblongata , and descend contra laterally.
Directly control fine movements of the distal segments of the limbs ( ex: fingers )

Question 15

What are ventral corticospinal tracts and how do they descend

Answer 15

tracts that Serve posture
Descend ipsilaterally and cross over at the spinal cross at the level they exit the cord. integrated and cross over more lower down

Question 16

Which nerve innervates the motor unit and where does it receive input form

Answer 16

Lower motor neurone. Receives input from many upper motor neurones ( ex: all tracts mentioned in this lecture ) .

Question 17

In a stroke if there is an intracerebral haemorrhage in the internal capsule causing pyramidal tract damage , what will happens

Answer 17

Rubrospinal tract and reticulospinal tract unopposed influence = flexor spasm in arms and extensor in legs

+ive Babinksi sign

Question 18

What is the Babinski sign

Answer 18

when stimulation of plantar spect of foot leads to extension , dorsiflexion or upward movement of the big toe away from the stimulant. Or fanning of toes

in healthy adult it should cause downward reflex not up

Question 19

What makes up the basal ganglia

Answer 19

1- globus pallidus
2- substantia nigra
3- putamen
4- Caudate nucleus

Group of neurons

Question 20

Where do all motor fibres pass through

Answer 20

Pass through the internal capsule, the space between the caudate nucleus and the putamen of the basal ganglia

Question 21

What are the two circuits of the basal ganglia

Answer 21

Putamen circuit and caudate circuit

Question 22

Describe the putamen circuit

Answer 22

Loop from the cerebral cortex to the putamen to the striatum then internal and external globes pallidus , thalamus then back to brain

Question 23

Problems in the putamen circuit could cause what problems

Answer 23

1- Athetosis : writhing and wriggling
2- Ballismus : large exaggerated movement ( twisting, bending )
3- Chorea : dance like movement

Question 24

Describe the caudate circuit

Answer 24

From cerebral cortex to caudate nucleus , then to striatum then globes pallidus and then to thalamus and then Brian

Question 25

Throwing a football is part of which circuit of the basal ganglia

Answer 25

Putamen circuit

Question 26

What is common in the caudate and putamen circuit

Answer 26

Dopaminergic pathway from Substantia nigra and striatum

Question 27

What is the role of the caudate circuit

Answer 27

Cognitive control of motor pattern sequences.

“What Pattern of movements will achieve desired goal”

Question 28

What is excitatory to the striatum in the caudate and putamen circuits

Answer 28

Substantia nigra

Question 29

What is inhibitory in the caudate and putamen circuits

Answer 29

1- Striatum inhibiton to globus pallidus

2- globus pallidus inhibition to subthalamic nuclei in thalamus

Question 30

What is hyper and hypo kinesia

Answer 30

Difficulty in balance between movement activation and movement suppression.

Hypo: Difficulty initiating movement
Hyper: tremor at rest , rigidity

Question 31

What common condition can we see hyper and hypo kinesia

Answer 31

Parkinson’s disease , as degeneration of dopaminergic neurons compromise the basal ganglia circuits

Question 32

Which condition is thought to be an excess of dopaminergic firing in the basal ganglia

Answer 32

Tourettes syndrome

Question 33

Why is movement less in Parkinson’s disease

Answer 33

Dopaminergic neurones from SN degenerate = turns of inhibition between striatum and globes pallidus and thus the inhibition between the GP and thalamus is turned off = less movement , harder to initiate movement

Question 34

What is the physiological classification of the flocculonodular lobe of the cerebellum

Answer 34

Vestibulocerebellum

Question 35

What is the medial cerebellum called

Answer 35

Spinocerebellum , includes the vermis and intermediate zone

Question 36

What are the lateral aspects of the cerebellum called

Answer 36

Cerebrocerebellum

Question 37

What is the cerebellum

Answer 37

1- involved in balance : Vestibulocerebellum

• equilibrium
• eye movements ( pursuit )

2- receives efferent copy of movement needed from Brian & proprioception signal from body of what it’s doing now and it’s job is to make both the same ( spinocerebellum )

3- Planning and pre programming movements ( cerebrocerebellum )

• second language
• learned skills
• accuracy

Question 38

If you learn a language after 8 years of age where is it stored in the Brian

Answer 38

Stored in the cerebellum ,considered a skill

Question 39

What might be seen if there are problems with the vestibulo and spinocerebellar problems

Answer 39

1- Wide stance
2- swaying while standing
3- inappropriate nystagmus
4- ataxic gait

Question 40

What might be seen if there are problems with the cerebrocerebellar

Answer 40

1- compromised movement with accuracy ( ex: can’t aim , can’t measure correctly )
2- movement decomposition ( not smooth movement )
3- intention tremor
4- intitiation delay
4- Kinaesthetic learning abilities lost