Basal Ganglia and Cerebellum Flashcards
What is found directly above the midbrain, posterior to the forebrain and between the cerebral hemispheres?
What makes up this named structure?
Diencephalon
- thalamus, epithalamus, hypothalamus, subthalamus
The diencephalon is said to form the walls of ______
third ventricle
Injury to the basal ganglia and the cerebellum results in _______
incoordination of movements
Name the lobes of the cerebellum.
- anterior lobe
- posterior lobe
- flocculonodular lobe
What is the cerebellum responsible for?
- Posture
- Balance
- Coordination of Movements
What is the exact location of the cerebellum?
- inferior to the Occipital lobe and temporal lobes
- within the posterior cranial fossa
- tentorium cerebelli seperates the cerebellum from the lobes
- falx cerebelli separates the cerebellar hemispheres
How is the cerebellum attached to the brainstem?
via 3 stalks
(called the peduncles) —middle cerebellar, inferior cerebellar, superior cerebellar
What is the central portion of the cerebellum termed as?
And on either sides of the vermis?
the vermis
—the hemispheres
What do the cerebellar peduncles carry?
- the MIDDLE and the INFERIOR peduncles carry info. IN
- Superior peduncle carries info. OUT
Name the afferents that arrive at the cerebellum.
- vestibular apparatus via Vestibular nuclei
- Spinal cord (pressure and somatic proprioceptors)
- cerebral cortex (via the pons)
Name the 3 layers, the cerebellar cortex is divided into.
- Molecular Layer (outer)
- Purkinje Cell layer (middle)
- Granule cell layer (inner)
What are the deep grey matter in the cerebellum?
- deep cerebellar nuclei
What do the afferents mainly project to in the cerebellum?
- the granule cell layer (INNER)
Which is the only layer, from which the cerebellum sends output projections?
- from the axons of the Purkinje cells
> synapse with deep cerebellar nuclei; allowing thr coordination of all motor tracts
Where do the efferents axons of the cerebellar nuclei synapse at?
- the thalamus (after crossing over the midline)
- and red nucleus
> thalamus sends fibres to the MOTOR cortex
What side of bodily coordination is the cerebellum in charge of?
- the hemispheres influence the IPSILATERAL side of body
- —-lesions> ipsilateral signs
What kind of cells are purkinje cells?
- inhibitory neurones
- release GABA
- —-therefore helps MODIFY movement
What occurs with bilateral cerebellar dysfxn?
- slowed, slurred speech (DYSARTHRIA)
- b/l incoordination of arms
- wide based gait, staggering
When is bilateral cerebellar dysfxn seen?
- with Acute Alcohol exposure
What is seen with unilateral cerebellar lesion?
- disturbance of coordination in LIMBS
- intention tremor
- unsteady gait
- —in the absence of weakness and sensory loss
What occurs with midline cerebellar lesion?
- disturbance of POSTURAL control
- pt will tend to FALL over when standing/ sitting
- preserved limb coordination
Why does a midline lesion present with postural problems?
- as the midline portion of the cerebellum carries the spinocerebellar tract
Name the 3 deep nuclei of the cerebellum
- Dentate
- Interposed
- Fastigial
Which deep nuclei is the MOST lateral and where does it project to?
Dentate
—-projects to the CONTRALATERAL VA, VL nuclei of the thalamus (same ones basal ganglia coordinates with) —–HELPS modify movements
