17 - Diencephalon, Basal Ganglia and the Cerebral Cortex

Question 1

Where is the diencephalon located in the brain?

Answer 1

Just below the corpus callosum.

Question 2

What 4 parts is the diencephalon divided into?

Answer 2

• The Thalamus
• The Epithalamus - habenula & pineal body
• Subthalamus
• Hypothalamus

Question 3

What is the main role of the diencephalon as a whole?

Answer 3

It relays sensory information between brain regions and relays sensory functions.

Question 4

What is the thalamus and what does it do?

Answer 4

Its the largest mass of grey matter in the brain and relays and integrates motor and sensory impulses between the higher centres of the brain peripheries.

Question 5

Where is the thalamus located?

Answer 5

In the middle of the brain below the corpus callosum.

Question 6

Where is the hypothalamus located?

Answer 6

• It sits below the hypothalamic sulcus within the medial wall of the third ventricle which separates the thalamus from the hypothalamus.
• Its also the most inferior part of the diencephalon.

Question 7

What is the role of the hypothalamus?

Answer 7

• Its the visceral control centre.
• Related to the endocrine centre and helps to maintain a state of homeostasis.

Question 8

How does the pituitary gland function?

Answer 8

The hypothalamus controls both lobes via the vascular link for the anterior pituitary (adenohypophysis) and a neural projection to the posterior pituitary (neurohypophysis).

Question 9

What is the basal ganglia?

Answer 9

A group of subcortical nuclei in the centre of the brain

Question 10

What are the 5 components of the basal ganglia?

Answer 10

• The caudate nucleus
• Putamen & Globus Pallidus
• Subthalamic nucleus
• Substantia nigra

Question 11

What does the caudate nucleus form?

Answer 11

The lateral wall of the lateral ventricle, it has a characteristic ventricular C-Shape.

Question 12

What does the putamen form?

Answer 12

The lateral aspect of the lentiform nucleus.

Question 13

Where is the putamen located?

Answer 13

• At the base of the forebrain the most lateral part of the basal ganglia
• On its inner concave surface is the globus pallidus.

Question 14

What is the function of the putamen?

Answer 14

To regulate motor functions and influence various types of learning.

Question 15

What is the function of the Globus pallidus?

Answer 15

Its a paired subcortical structure composed of inhibitory GABAergic neurons which fire irregularly at a high frequency.

Question 16

Where is the subthalamic nucleus and what does it do?

Answer 16

• Inferior to the thalamus and right above the substantia nigra
• Its job is to slow down decision making.

Question 17

Where is the substantia nigra and what does it do?

Answer 17

• Below the subthalamic nucleus with a characteristically dark appearance due to the neuromelanin in its cells.
• Loss of cells here cause Parkinson’s

Question 18

What is a direct function of the basal ganglia?

Answer 18

To facilitate movement by disinhibition.

Question 19

What is an indirect function of the basal ganglia?

Answer 19

The inhibition of unwanted movements.

Question 20

How does the basal ganglia interact with the cerebral cortex?

Answer 20

Provides a feedback mechanism to the cortex modulating and refining cortical activation.

Question 21

What is the cerebral cortex?

Answer 21

The outer layer of the brain divided into different sensory parts.