Central Control of Movement

Question 1

Highest Level of Motor Control

Answer 1

Why? Goals to be achieved. Neocortical association areas (sensations, memories) primarily, but basal ganglia also involved

Question 2

Middle Level of Motor Control

Answer 2

How, what, and when to move? Sequences/tiiming. Uses motor cortex area 4 and 6 for premotor and supplementory motor, as well as cerebellum to share same sequential pathways as before

Question 3

Lowest Level of Motor Control

Answer 3

Activation of motor neurons, using cortex, brain stem, and spinal cord

Question 4

Posterior Parietal Cortex

Answer 4

Areas 5 and 7, sensory input that sends info the motor

Question 5

2 Sources of Corticospinal Tract

Answer 5

Primary motor cortex (2/3) and somatosensory cortex (1/3)

Question 6

2 Parts/Functions of Reticulospinal Tract

Answer 6

Pontine (medial) - enhances antigravity reflexes

Medullary (lateral) - relaxes antigravity reflexes

Question 7

Main Function of Basal Ganglia

Answer 7

Starting/stopping movement

Question 8

3 Cortical Regs of Movement

Answer 8

Parietal cortex (5&7) do sensory then output to premotor area (6)
Prefrontal cortex does decision making/consequential input then outputs to premotor area (6)

Question 9

Lentiform Nucleus

Answer 9

Putamen and globus pallidus, all together but GP is more medial

Question 10

2 Structures Not Technically in BG but Involved in its Reg

Answer 10

Subthalamic nuc and substantia nigra

Question 11

Basic Pathway of Globus Pallidus (int) to Motor Cortex

Answer 11

GPi has tonic inhibition of thalamus, so it can’t excite motor cortex. Interruption of GPi allows thalamus to fire and excite motor cortex

Question 12

Direct Pathway of BG Regulation of Movement

Answer 12

Excitatory: Cortex and Substantia nigra both stimulate putamen which inhibits GPi, releasing its inhibition

Question 13

Indirect Pathway of BG Regulation of Movement

Answer 13

Inhibitory: Cortex and Substantia nigra stimulate putamen, which also inhibits GPext, which was inhibiting Subthalamic nucleus which stimulates GPi. So Inhibition of subthalamic nucleus is released, so it stimulates GPi to inhibit thalamus

Question 14

Huntington Disease Symptoms

Answer 14

Hyperkinetic disorder - chorea/dementia/psychiatric disorder

Question 15

Huntington Disease Cause

Answer 15

Striatum/putamen fibers going to GPe degenerate, so you get less tonic inhibition and thus hyperkineticism

Question 16

Parkinson Disease Symptoms

Answer 16

Hypokinetic - rigidity, lack of expression, difficulty starting/stopping movements, and resting tremor (pill rolling, SC firing)

Question 17

Parkinson Disease Cause

Answer 17

DAergic neurons from substantia nigra degenerate, and striatum/putamen activates GPext more so you get over inhibition

Question 18

Athetosis

Answer 18

Slow, writhing motions

Question 19

Ballismus

Answer 19

Flailing/flinging motions of extremities

Question 20

Hemiballismus

Answer 20

Unilateral ballismus due to contralateral lesion in subthalamic nucleus