Basal Ganglia - Revision

Question 1

What are the main components of the basal ganglia?

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Basal Ganglia - Revision

Answer 1

What are the main components of the basal ganglia?

• Caudate
• Putamen
• Globus Pallidus
• Subthalamic Nucleus
• Substantia Nigra.

Question 2

Where is the caudate located?

Basal Ganglia - Revision

Answer 2

In the cerebrum.

Question 3

What is the role of the putamen in the basal ganglia?

Basal Ganglia - Revision

Answer 3

The putamen, located in the cerebrum, works with the caudate as a primary input nucleus.

Question 4

Identify the location and basic function of the globus pallidus.

Basal Ganglia - Revision

Answer 4

Located in the cerebrum, the globus pallidus acts as an output nucleus, relaying information to the thalamus.

Question 5

Describe the subthalamic nucleus and its importance in the basal ganglia.

Basal Ganglia - Revision

Answer 5

Located inferior to the thalamus, it is part of the feedback loop that regulates movement.

Question 6

Where is the substantia nigra located and what are its two major divisions?

Basal Ganglia - Revision

Answer 6

Located within the midbrain, it is divided into

• substantia nigra pars compacta
• substantia nigra pars reticulata

Question 7

What is the role of substantia nigra pars reticulata in the basal ganglia circuit?

Basal Ganglia - Revision

Answer 7

It functions as an output nucleus, channeling information primarily to the thalamus.

Question 8

Explain the significance of input and output nuclei in the basal ganglia.

Basal Ganglia - Revision

Answer 8

Input nuclei, like the caudate and putamen (striatum), receive information from the cortex and send it to the output nuclei, which then relay processed information back to the cortex via the thalamus.

Question 9

How does the basal ganglia’s location affect its function?

Basal Ganglia - Revision

Answer 9

Located deep within the white matter of the cerebral hemispheres, it is strategically placed to influence motor control, executive functions, and emotional processes.

Question 10

What is the collective term for caudate and putamen in the basal ganglia?

Basal Ganglia - Revision

Answer 10

They are collectively referred to as the striatum, a major input site for the basal ganglia.

Question 11

What are the two primary functions of the basal ganglia?

Basal Ganglia - Revision

Answer 11

1. Motor control
2. Non-motor functions (decision making, emotional processing, and learning).

Question 12

Which basal ganglia loop is responsible for initiating and suppressing movements?

Basal Ganglia - Revision

Answer 12

The Motor Loop

Question 13

What is the function of the Oculomotor Loop within the basal ganglia?

Basal Ganglia - Revision

Answer 13

It helps in determining spatial attention and creating fast eye movements (saccades).

Question 14

Describe the role of the Goal Directed Behavior Loop in the basal ganglia.

Basal Ganglia - Revision

Answer 14

It evaluates information for decision making, planning, and choosing actions.

Question 15

What are the implications of a lesion in the Social Behavior Loop?

Basal Ganglia - Revision

Answer 15

It could lead to impulsivity, frustration, acts of violence, hypersexuality, and criminal behavior.

Question 16

How does the Emotion Loop affect behavior?

Basal Ganglia - Revision

Answer 16

It integrates emotional processing and is involved in reward-seeking behaviors, making predictions, and potentially in addictions.

Question 17

What are the symptoms of a basal ganglia stroke affecting the Emotion Loop?

Basal Ganglia - Revision

Answer 17

Depression, emotional blunting, and mask-like facial expressions.

Question 18

How does the basal ganglia interact with the thalamus and cortex in the context of motor functions?

Basal Ganglia - Revision

Answer 18

It receives inputs from the cortex, processes them through its loops, and sends outputs back to the cortex via the thalamus to initiate or suppress movements.

Question 19

What is the ‘Go’ pathway in the basal ganglia’s motor control?

Basal Ganglia - Revision

Answer 19

It activates the motor and premotor cortex, assisting with the initiation of voluntary movements.

Question 20

Describe the ‘No-Go’ pathway of the basal ganglia.

Basal Ganglia - Revision

Answer 20

This pathway inhibits or decreases thalamocortical activation to suppress unwanted movements.

Question 21

What potential cognitive deficits could arise from a caudate head infarction?

Basal Ganglia - Revision

Answer 21

Inattention, distractibility, disorientation, poor concentration, and short-term memory issues.

Question 22

How does the basal ganglia contribute to decision making and judgment?

Basal Ganglia - Revision

Answer 22

Prioritizing information and executive functions.

Question 23

What is the impact of the basal ganglia on learning and memory?

Basal Ganglia - Revision

Answer 23

It plays a role in selecting desired behaviors and learning from rewarded behaviors.

Question 24

What effect does the basal ganglia have on eye movements?

Basal Ganglia - Revision

Answer 24

It regulates eye movements through the Oculomotor Loop, affecting how fast and accurately eyes can move to track objects.

Question 25

Explain the concept of ‘desired behaviors’ in the context of the basal ganglia’s functions.

Basal Ganglia - Revision

Answer 25

The basal ganglia help select and facilitate actions that are deemed necessary or beneficial, while preventing undesired actions, through its intricate network of loops and pathways.

Question 26

What type of eye movement is involved in the Oculomotor loop and can be impaired in pathology.

Basal Ganglia - Revision

Answer 26

Fast (Saccadic eye movements)

Question 27

You are seeing a patient post-CVA, and they are having trouble demonstrating feelings of happiness, sadness, and other emotions due to their lack of facial expressions. What non-motor loop is affected?

Basal Ganglia - Revision

Answer 27

The Emotion Loop.

Question 28

What is the correct order of basal ganglia circuitry for all loops?

Basal Ganglia - Revision

Answer 28

D. Cortex → basal ganglia → thalamus → cortex.