Mod 5 Basial Ganglia Flashcards
What are the three most important basal ganglia
Globus pallidus
Caudate
Putamen
The globus pallidus and the putamen are known as____
Lenticular nucleus
The putamen and caudate nucleus are known as
Striatum
Corpus striatum
Caudate and lenticular nucleus
- caudate, putamen, globus pallidus [+ accumbens]
BG are ___ and ____ to the thalamus
Lateral and anterior
What is located lateral to the genu of the internal capsule and medial to the putamen
Globus pallidus
The ____ is located lateral to the genu of the internal capsule and to the globus pallidus
Putamen
The ___ located medial to anterior limb of internal capsule
Caudate nucleus
BG play an important role in
Posture and background muscle tone
Integration of motor activity
What is the pyramidal tract
Direct motor system synapsing link to LMNs
What is the extrapyramidal system
Indirect motor system/multi-synapsing link to LMNs
___ and ____ both play a role in planning and integrating of movements associated with motivational and emotional stimuli
Nucleus accumbens and globus pallidus
What is the nucleus accumbens
Continuous with caudate and putamen
It is a link to the limbic system
The input BG nuclei include:
Caudate, putamen and accumbens (striatum)
True or false: most input are inhibitory
False: excitatory
Output is inhibitory
Main input of BG comes from ___
Cerebral cortex
The output form the BG acts to influence _______
Cortical motor activities
The output BG include
Globus pallidus (primarily) and substantia nigra
The ____ conveys info from the head and neck. ____ conveys info for the rest of the body
Substantia nigra
Globus pallidus
True or false: None of the BG projects caudally to lower brainstem or spinal cord
True
The ____ includes all the BG except ___
Intrinsic
Striatum
The intrinsic BG nuclei
Includes all BG except the striatum
Link the input and output BG
Two pathways: direct and indirect
The ___ along with the ____ provide an interface between our sensory systems and motor responses
BG
Cerebellum
The direct pathway
From the striatum to directly to globus pallidus (GP)
The indirect pathway
to the GP –> to sub thalamic nucleus –> GP or substantia nigra
What is the principled role of the BG?
In association with the pyramidal system is to help execute learned patterns of skilled movements
What nucleus controls gross intentional bodily movements, both conscious and unconscious
Caudate nucleus
The ____ works with caudate to help execute movement patterns that are highly complex, such as technical and athletic skills
Putamen
The globus pallidus controls
Background positioning of gross body parts at the onset of complex movement patterns
Which nucleus has a role in walking and other gross rhythmic body movements?
Sub thalamic nucleus
What is the main output pathway for the neurotransmitter, dopamine
Substantia nigra
What role does the substantia nigra have?
Role in muscle tone and movement smoothing
What is dyskinesia
Lesions to extrapyramidal systems and BG. Characteized by “release phenomenon” and by unwanted, extraneous movement
Hypokinesia
Problems with substantia nigra
Less dopamine
No excitation of striatum
What is the result of hypokinesia
Excessive inhibition of thalamus
Paucity of movement (scarcity/lack)
Parkinson’s
Hyperkinesia
problems with sub thalamic nucleus degeneration or degeneration of striatum
What is the result of hyperkinesia
Sub thalamic nucleus can’t excite internal globus pallidus –> no inhibition of thalamus
Result- too much movement (Huntington’s disease)
Putamen circuit
Helps execute learned patterns of skilled movements
E.g.- piano playing
The putamen circuit includes
Globus pallidus, putamen, thalamus and the primary motor cortex
Caudate circuit
Role: cognitive control of motor activity
Actions occur from the thoughts we generate
E.g. - wanting to reach for a cup
The caudate circuit receives input from:
Frontal, parietal, occipital and temporal association vortexes
Determines which movements should be used with movements
Basal ganglia input is primarily from the ________; most basal ganglia output is to the _______ via the________.
Cortex; cortex via the thalamus
Functions of the basal ganglia include
Inhibition of unwanted movement
Postural control
Smoothing and refining movement
The nucleus accumbens is functionally related to the __________ and receives input from the ___________.
basal ganglia
Limbic system
LMNs have their cell bodies
Within the spinal cord and brainstem
