Basal Ganglia Flashcards
What are the components of the corpus striatum (2)
- Caudate
2. Lentiform nucleus
What are the components of the lentiform nucleus (2)
- Putamen
2. Globus pallidus
What make up the basal ganglia (5)
- Caudate
- Putamen
- Globus pallidus
- Subthalamic nucleus
- Substantia nigra
What are the components of the striatum (neostriatum) (2)
- Caudate
2. Putamen
True or False:
The basal ganglia participates in complex networks that influence descending motor systems
True
True or False:
The basal ganglia does not project directly to the periphery
True
True or False:
Movement abnormalities associated with the basal ganglia disorders differ markedly from those of the cerebellum
True
What does lesion to the basal ganglia result in (2)
- Hyperkinetic
2. Hypokinetic
What are hyperkinetic movement disorders
Uncontrolled voluntary movements that produce a random pattern of jerks and movements
What are hypokinetic movement disorders
Characterized by rigidity, slowness, and difficulty initiating movements
When does hyperkinetic movement occur
You have lost your modulation (inhibition) of the movement
When does hypokinetic movement occur
You have excessive modulation (inhibition) of movement
What are the 4 main channels of the basal ganglia
- Motor
- Oculomotor
- Prefrontal
- Limbic
True or False:
Each channel of the basal ganglia passes through slightly different pathways and projects to different regions of the frontal cortex
True
What is the major motor channel function of the basal ganglia
Disinhibition
True or False:
the motor channel function provides feedback to the cerebral cortex for the initiation and control of procedural movements
True
What does the motor channel do (2)
- Facilitates intentional movements
2. Inhibits extraneous movements
The motor channel forms a lop that originates in almost every area of the cerebral cortex and eventually terminates after enormos convergence with the basal ganglia on (2)
- The upper motor neurons in the motor and premotor areas of the frontal lobe
- Superior colliculus
What 2 cortices do not communicate with the basal ganglia
- Primary auditory cortex
2. Primary visual cortex
True or False:
The parietal cortex allows us to detect motion in the visual field
True
In an anterior slice of the basal ganglia can you see the globus pallidus
No
In a posterior slice of the basal ganglia can you see the globus pallidus
Yes
Why are the caudate and putamen collectively referred to as striatum
Due to the striated look in between them
What causes the striated look
Axon bridges communicating between the caudate and the putamen
How do you know that you are in a posterior slice of the basal ganglia
You can see the globus pallidus
Where do virtually all of the basal ganglia afferents arrive
Striatum
What does the caudate primarily receive input from (5)
- Premotor cortex
- Limbic regions
- Cortical association regions
- Frontal eye fields
- Supplementary motor areas
What does the putamen primarily receive input from (4)
- Primary motor cortex
- Primary somatosensory cortex
- Substantia nigra (pars compacta)
- Centromedian nucleus of thalamus (indirect cortical input)
Most of the cortical inputs of the basal ganglia afferents for motor channel are ______ and use _____
- Excitatory
2. Glutamate
Dopamin input from the pars compacta causes what at the D1 and D2 receptors
D1 receptors: excitatory
D2 receptors: inhibitory
Do basal ganglia outputs inhibit or excite the thalamus
Inhibit
Where do the basal ganglia outputs arise from (2)
- Substantia nigra pars reticulata
2. Internal segment of the globus pallidus
What do the outputs from the substantia nigra pars reticulata act on (2)
- Head
2. Neck
What do the outputs from the internal segment of the globus pallidus act on (1)
- Body
Are the outputs inhibitory or excitatory
Inhibitory (GABA)