Pathways And Centres Involved In Movement Flashcards
What are the 3 functions of the basal ganglia?
Normal initiation of movement
Control of movement
Stopping of movement
The basal ganglia sends what specific information through the thalamus to the cerebral cortex?
1) dampen cerebral cortex
2) excite cerebral cortex
What is dyskinesia?
Abnormal involuntary movements
Lesions of the basal ganglia cause what?
Dyskinesia - abnormal involuntary movements
The basal ganglia is made up of what two components?
Corpus striatum
Amygdala and claustrum
What is the corpus striatum made from?
Neostratum and paleostiatum
What is the neostratum made up of?
Caudate nucleus and putamen
What is the lentiform nucleus made up of?
Putamen
Gloves pallid is
What is the embryological origin of the basal ganglia?
Telencephalon
The anatomical basal ganglia is made of what 4 components?
Caudate nucleus
Lentiform nucleus - putamen and globus pallidus
Amygdala
Claustrum
The globus pallidus is split into two parts know as:
Interna
Externa
The functional basal ganglia is made of which 5 components?
Caudate nucleus Putamen Globus pallidus Subthalamus Substantia nigra
The substantia nigra is functionally part of what structure?
Globus pallidus interna
The substantia nigra is split into 2 parts known as:
Pars compacta
Pars reticulata
The pars compacta contains what type of cells? What do they produce?
Melanin
Produce dopamine
Individually, are the fibres from the cortex to the striatum excitatory or inhibitory?
Excitatory
Individually, are the fibres from the striatum to the globus pallidus interna and substantia nigra excitatory or inhibitory?
Inhibitory
Individually, are the fibres from the globus pallidus interna and substantia nigra to the thalamus excitatory or inhibitory?
Inhibitory
Individually, are the fibres from the thalamus to the cortex excitatory or inhibitory?
Excitatory
What does the internal circuitry of the basal ganglia do?
Modification
Turns muscles ‘on and off’
What is the function of the direct pathway?
Facilitate behaviour and movements that are required
What is the function of the indirect pathway?
Inhibit unwanted behaviours and movements
What is chorea? And in what disease does it present?
Jerky involuntary movements
Huntingtons disease
Draw out the direct pathway
See slide 8
Draw out the indirect pathway
See slide 9
The direct pathway causes excitation or inhibition of the thalamus?
Excitation
The indirect pathway causes excitation or inhibition of the thalamus?
Inhibition
What is the function of the substania nigra pars compacta?
Releases dopamine Initiates movement Excites the direct pathway Inhibits the indirect pathway = double excitation
Damage to the basal ganglia means disordered movement on what side of the body?
Contralateral side
What are the signs and symptoms of basal ganglia damage?
Slow movements (hypokinesia) Poor initiation of movement Little steps Lack of facial expression Lack of blinking Rigidity Tremor
Why is there no initiation of movement in basal ganglia damage?
Dopenergic fibers do not fire
No excitation/inhibition
= no initiation
Parkinsons disease is disease of the basal ganglia involving disruption of which input?
Nigrostriatal
How does hyperkinetic disorders occur?
Degeneration of subthalamic nucleus = excitation to globus pallidus
Degeneration of inhibitory fibers from striatum to globus pallidus
What does hyperkinetic mean?
Unwanted movement
