Week 3: Basal Nuclei Flashcards
What are the basal nuclei (ganglia)?
A collection of deep brain nuclei involved in voluntary movement, cognition, and behavior.
What happens when the basal nuclei are damaged?
It causes movement and other neurological disorders.
What are the main components of the basal nuclei?
Lentiform nucleus, caudate nucleus, nucleus accumbens, subthalamic nucleus, and substantia nigra.
What structures make up the lentiform nucleus?
The putamen and globus pallidus.
What are the segments of the globus pallidus?
Lateral (outer) and medial (inner) segments.
Why is the globus pallidus pale in appearance?
Due to the presence of myelinated fibers forming internal connections of the basal ganglia.
What are the parts of the caudate nucleus?
Head, body, and tail.
Where does the head of the caudate nucleus protrude?
Into the anterior horn of the lateral ventricle.
What is the nucleus accumbens?
A region where the head of the caudate and the putamen merge, part of the reward and limbic system.
What type of input does the nucleus accumbens receive?
Extensive dopaminergic input.
Where is the subthalamic nucleus located?
In the diencephalon.
Where is the substantia nigra located?
In the midbrain.
What are the two parts of the substantia nigra?
Compact part (SNc) and reticular part (SNr).
What is found in the compact part of the substantia nigra (SNc)?
Dopaminergic neurons containing melanin.
What is the reticular part of the substantia nigra (SNr)?
The ventral portion containing non-dopaminergic neurons.
What is the anatomical and functional difference in the composition of the corpus striatum?
Anatomically, the corpus striatum consists of the caudate nucleus and lentiform nucleus. However, it is functionally divided into the striatum and the pallidum.
What is the traditional function of the basal nuclei?
Regulation of the initiation of voluntary movements.
What non-motor functions are the basal nuclei involved in?
Emotional regulation, cognitive functions, and behavior modulation.
How many functional loops are associated with the basal nuclei?
Three: motor loop, limbic loop, and prefrontal (cognitive-executive) loop.
What is the role of the motor loop?
Regulates voluntary movement by enabling desired movements and inhibiting undesired movements.
Where does the motor loop originate and terminate?
Originates in the motor cortex and terminates in the supplementary motor area (SMA) via the thalamus.
Which structure serves as the input center of the basal nuclei?
The striatum (caudate and putamen).
What is the output center of the basal nuclei?
The globus pallidus (primarily the internal segment).
What neurotransmitter is deficient in Parkinson’s disease?
Dopamine.
