Basal Ganglia Flashcards
Historically, the basal ganglia were once believed to be part of what motor pathway?
Extrapyramidal Pathway
The basal ganglia are part of a sub-cortical loop feeding back onto the ________
Motor Cortex
The basal ganglia modulate activity in the ___________
Corticospinal Tracts
The basal ganglia simply ________ the output from the ___________, and therefore ________ activity in the corticospinal tracts.
Modulate
Motor Cortex
Modulate
Often times, the term “extrapyramidal” is used to describe pathologies of the _________
Basal Ganglia
What is the function of the basal ganglia?
To suppress unwanted and inappropriate cortical activity
How does the basal ganglia play a major role in motor control?
Via outputs to the motor cortex
How does the basal ganglia play a major role in moods and emotions?
Via outputs to orbital frontal cortex
How does the basal ganglia play a major role in organizing goal-directed behaviors and complex thought?
Via outputs to pre-frontal association cortex
For this course, we should focus our attention on the basal ganglia and their role in __________ :)
Motor control
The major motor function of the basal ganglia is to encode “________” or combinations of “_______”
“motor subroutines”
i.e. flexion at the shoulder, smiling
During complex motoric activity, what part of the brain determines which individual units of motor activity are required and in what order?
Cerebral Cortex
The cortex elicits the appropriate “subroutines” from the basal ganglia, which in turn project to what neurons in the pre and primary motor cortex?
Upper Motor Neurons
Which neurons actually carry out the “subroutines”?
Upper motor neurons
Where are the basal ganglia located?
lie near the junction of the brain stem and cerebrum
The basal ganglia are a set of telencephalic, diencephalic and __________ structures
mesencephalic
The components of the basal ganglia include what five things?
- Caudate nucleus
- Putamen nucleus
- Globus Pallidus
- Subthalamic Nucleus
- Substantia Nigra
What component of the basal ganglia is an elongated structure that follows the contours of the lateral wall of the lateral ventricals?
The caudate nucleus (“having a tail”)
What are the 3 regions of the caudate nucleus and what regions are they associated with?
- Head (associated with the anterior horn of the lateral ventricles)
- Body (associated with the atrium region of the lateral ventricles)
- Tail (associated with the inferior horn of the lateral ventricals)
What are the borders bounding the caudate nucleus?
Medially bounded by the lateral ventricals
Laterally bounded by the internal capsule
What part of the basal ganglia is a flattened lens-shaped nucleus that lies lateral to the internal capsule?
Putamen Nucleus
In many lower mammals, the putamen nucleus and the ________ nucleus are fused, and have similar circuitry
Caudate
The major difference in the circuitry between the putamen nucleus and the caudate nucleus relates to what?
The inputs
The putamen nucleus receives inputs from where?
The motor Cortex
The caduate nucleus receives inputs from where?
Non-motor areas of the cortex
Lateral to the putamen nucleus lies what two structures?
External capsule
Cortex of the insular lobe of the cerebrum
The globus pallidus (a component of the basal ganglia) is made of what two nuclei?
Pars interna
Pars Externa
Is the pars interna of the globus pallidus a major EFFERENT or AFFERENT nucleus of the basal ganglia?
Efferent
Is the PARS INTERNA or PARS EXTERNA an internal relay nucleus?
Pars Externa
