11. Control Of Movement

Question 1

What do lateral pathways transmit?

Answer 1

Voluntary movements originating in the primary motor cortex and red nuclei of mesencephalon (rubrospinal)

Question 2

What are the components of the lateral pathways?

Answer 2

Corticospinal (pyramidal) tract

Rubrospinal tract

Question 3

Which tract innervates proximal muscles?

Answer 3

Anterior corticospinal tract.

Lateral corticospinal tract innervates limb muscles

Question 4

What would be the effect of a left corticospinal lesion?

Answer 4

Paralysis on the right side

Question 5

What is the function of the ventromedial pathways?

Answer 5

Control posture and locomotion

Question 6

What are the components of the ventromedial pathways?

Answer 6

Vestibulospinal tract - head balance, turning
Tectospinal tract - orientation
Pontine and medullary reticulospinal tract - enhances postural reflex, liberates postural muscles from reflex

Question 7

What are the origins of the ventromedial pathways?

Answer 7

Vestibulospinal - vestibular nuclei in brainstem
Tectospinal - tectum (mesencephalon: superior and inferior colliculi)
Reticulospinal - reticular nuclei in brainstem

Question 8

What is the difference between the promotor area and the supplementary motor area?

Answer 8

PMA responsible for sensory guidance of movement, SMA responsible for intentional preparation for movement
Innervate different groups of muscle

Question 9

What are the contributions of the posterior parietal and prefrontal cortex in the planning of movement?

Answer 9

Represent the highest levels of motor control. Decisions made about actions and their outcome
Areas 5 and 7

Question 10

What are the functions of the anterior frontal lobes?

Answer 10

Abstract thought, decision making, and anticipating consequences

Question 11

What occurs in area 6?

Answer 11

Conversion of actions into signals specifying how actions will be performed
Important in initiating planned movement

Question 12

What are the primary structures of the limbic system?

Answer 12

Amygdala
Hypothalamus
Hippocampus
Thalamus
Basal Ganglia
Cingulate Gyrus

Question 13

How does the limbic system store memories?

Answer 13

Amygdala is emotion centre which is closely connected to hippocampus which forms memories

Question 14

What is the function of the basal ganglia?

Answer 14

Selection and initiation of willed movements

Question 15

What is referred to as the motor loop?

Answer 15

The excitatory connection from the motor cortex (SMA) to the putamen of the basal ganglia

Question 16

How does Parkinson’s Disease affect the brain?

Answer 16

Increases inhibition of the thalamus by the basal ganglia, resulting in difficulty initiating willed movements. Due to degeneration of dopaminergic substantia nigra

Question 17

How does Huntington’s disease affect the brain?

Answer 17

Loss of inhibition with loss of neurons in caudate, putamen, and globus pallidus. Leads to violent unwanted movements on one side of body

Question 18

How is movement initiated by the primary motor cortex?

Answer 18

Electrical stimulation of area 4 contracts small group of muscles, activity from several neurons in M1 encodes force and direction of movement

Question 19

How are saccadic eye movements controlled?

Answer 19

By the superior colliculus