Neuroanatomy- Basal Ganglia and Cerebellum Flashcards
What does the cerebellum control?
Movement
What are the 3 lobes of the cerebellum?
Anterior lobe
Posterior lobe
Tiny flocculonodular lobe
What covers the top of the cerebellum?
Tentorium cerebelli
What is name of the 3 stalks that attach the cerebellum to the brainstem?
Peduncles
What are the names of the 3 peduncles?
Superior, middle and inferior cerebellar peduncle
What is the name given to the strip down the midline of the cerebellum?
Vermis
What is the cerebellum also called?
The ‘Arbor Vitae’ or The Tree of Life
Why is the cerebellum called the tree of life?
The gyri look like leaves or foliage and are so called “folia”
What are the 3 layers of the cerebellar cortex from outer to inner?
Molecular layer
Purkinje cell layer
Granule cell layer
What is contained in the granule cell layer?
More than 50% of all neurons are found in this layer
How do afferent (inputs) to the cerebellum enter?
Via cerebellar peduncles and project to mainly the granule cell layer
How do efferent (outputs) exit the cerebellum?
Only output is via axons of Purkinje cells
What are the 3 function divisions of the cerebellum?
Vestibulocerebellum
Spinocerebellum
Pontocerebellum
Cerebellar hemispheres influence ipsilateral or contralateral side of the body?
Ipsilateral
What clinical signs are a result of unilateral hemispheric lesions of the cerebellum?
Disturbance of coordination in limbs
Tremor and unsteady gait
What clinical signs are a results of bilateral cerebellar dysfunction?
Slowed, slurred speech (dysarthria)
Bilateral incoordination of the arms
Staggering, wide based gait (cerebellar ataxia)
(Acute alcohol exposure mimics this)
What are the functions of the basal ganglia?
Facilitate purposeful movement
Inhibit unwanted movement
Role in posture and muscle tone
What does the basal ganglia comprise of?
Caudate nucleus Putamen Globus pallidus Subthalamic nucleus Substantia nigra
What does the lenticular nucleus comprise of?
Putamen
Globus pallidus
What does the striatum comprise of?
Caudate nucleus
Putamen
What does the corpus striatum comprise of?
Caudate nucleus
Putamen
Globus pallidus
Where is the substantial nigra located?
In the midbrain near the cerebral aqueduct
Which disease shows degeneration of the substantial nigra?
Parkinson’s disease
In contrast to cerebellar lesions, which side of the body is affected in unilateral lesions of basal ganglia?
Contralateral side of body
Basal ganglia lesions cause paralysis, sensory loss, loss of power and ataxia. True/false?
False
Basal ganglia lesions cause changes in muscle tone, dyskinesias (abnormal, involuntary movement). True/false?
True
Name some examples of dyskinesias?
Tremor (sinusoidal movements)
Chorea (rapid, asymmetrical movements usually affecting distal limb)
Myoclonus (muscle jerks)
Name disorders associated with the basal ganglia?
Parkinson’s disease
Huntington’s disease
