Basal Ganglia

Question 1

What are components of the basal ganglia?

Answer 1

Striatum, Globus pallidus, Subthalamic nucleus, and Substantia nigra

Question 2

What are the 3 parts of the Striatum?

Answer 2

Caudate nucleus, nucleus accumbens, and putamen

Question 3

What are the 2 parts of the Globus pallidus?

Answer 3

External segment and internal segment

Question 4

What are the 2 parts of the Substantia nigra?

Answer 4

Compact part and reticular part?

Question 5

What makes up the Lenticular nucleus?

Answer 5

Putamen, Globus pallidus (external and internal segments)

Question 6

What are the functions of the motor system of basal ganglia?

Answer 6

Planning, initiation, facilitation, and suppression of movement

Question 7

What composes the motor system?

Answer 7

Caudate nucleus, putamen, and globus pallidus

Question 8

What does the limbic system of the basal ganglia control?

Answer 8

Mood, motivation, and behavior

Question 9

What composes the limbic system?

Answer 9

Nucleus accumbens (amygdala)

Question 10

How do basal ganglia control activity of thalamic nuclei?

Answer 10

Via inhibitory outputs from the globes pallid us and substantial nigra

Question 11

What are the two neuronal pathways through the basal ganglia?

Answer 11

Direct pathway and indirect pathway

Question 12

What is the direct pathway?

Answer 12

Activity increases thalamic activity by reducing inhibitory basal ganglia output

Question 13

What is the indirect pathway?

Answer 13

Activity reduces thalamic activity by increasing inhibitory basal ganglia output

Question 14

Descending pathways?

Answer 14

No descending pathway to lower motor neurons

Question 15

Connections?

Answer 15

Basal ganglia connect with the cerebral cortex on same (ipsilateral) side

Question 16

Ongoing movements?

Answer 16

Basal ganglia neurons fire continually during movement

Question 17

Movement initiation?

Answer 17

Basal ganglia neurons fire prior to the upper motor neuron

Question 18

Dopamine from substantial nigra ALWAYS facilitates what?

Answer 18

Movement

Question 19

In the Direct Pathway, Dopamine is what?

Answer 19

Excitatory

Question 20

In the Indirect Pathway, Dopamine is what?

Answer 20

Inhibitory

Question 21

Which pathway facilities movement?

Answer 21

Direct Pathway; Indirect Pathway suppressed movement

Question 22

What does the Cerebellum connect with?

Answer 22

Ipsalateral spinal cord and contralateral cerebrum (via thalamus)

Question 23

Neither Basal Ganglia nor the cerebellum have direct connections with what?

Answer 23

Lower motor neurons

Question 24

Both Basal Ganglia and Cerebellum receive fibers from what?

Answer 24

Widespread areas of the cortex

Question 25

Both Basal Ganglia and Cerebellum converge on what?

Answer 25

Motor areas of frontal lobe via dorsal thalamus

Question 26

What type of inhibition is prevalent in both systems?

Answer 26

GABA inhibition

Question 27

What is an important different between Basal Ganglia and the Cerebellum?

Answer 27

The Cerebellum receives direct sensory input mostly through the spino-cerebellar afferences. Basal Ganglia do not receive sensory input.

Question 28

Basal Ganglia are involved in what 2 functions?

Answer 28

Initiation of movements and selection of motor patterns.

Question 29

Patients with Parkinson’s Disease lack the ability to do what?

Answer 29

Initiate movements

Question 30

Huntington’s Disease may a result of what?

Answer 30

Loss of selectivity

Question 31

What are symptoms of Parkinson’s Disease?

Answer 31

1. Bradykinesia (slowness of movement)
2. Resting tremor
3. Rigidity
4. Expressionless face
5. Difficulty initiating movement

Question 32

Chorea Huntington

Answer 32

Random, uncontrollable movements, cognitive deficits

Question 33

Hemiballismus

Answer 33

Unilateral large amplitude arm and leg movements causing falls and preventing postural maintenance

Question 34

Dystonia

Answer 34

Sustained muscle contractions that result in repetitive movements, twisting, and abnormal postures