How is the cerebellum attached to the brainstem
Via 3 stalks termed peduncles
superior, middle, inferior
what are the three layers of the cerebellar cortex
molecular layer
purkinje layer
granular
What are the lobes of the cerebellum
anterior
posterior
flocculus
What are afferent signals to the cerebellum
Spinal cord - somatic proprioceptors and pressure receptors
Cerebral cortext via pons
vestibular apparatus via vestibular nuclei
all enter via peduncles
where in the cerebellum fo afferent signals enter
mainly granular layer
what are the efferent projections of the cerebellum
Only output is via axons of purkinje cells and control coordination the functions of the motor tracts
where do efferent projections synapse in the cerebellum
the deep cerebellar nucleus (grey matter)
most efferent axons of the depp cerebellar nucleu cross the midline and synapse in the thalamus which in turn sends it to the motos cortex
Which side of the body to cerebellar hemishperes influence
the ipsilateral side
what would a midline cerebellar lesion cause
disturbance of postural control
what would a bilateral cerebellar lesion cause
dysarthria
incoordination of arms bilaterally
ataxia - wide, staggering gait
What would a unilateral cerebellar lesion cause
disturbance of limb coordination
intention tremor
What are the functional divisions of the cerebellum
Spinocerebellum (midline)
vestibulocerebellum
Pontocerebellum
What are the functions of the basal ganglia
to facilitate purposeful movement
inhibit unwanted movements
role in posture and muscle tone
What are the basal ganglia
a number of masses of grey matter located near the base of each cerebral hemisphere
what makes up the basal ganglia
caudate nucleus
putamen +globus pallidus =lenticular nucleus
subthalamic nucleus
substancia nigra
what is the striatum
caudate nucleus and putamen
what is the corpus striatum
striatum and globus pallidus
which side of the body do unilateral basal ganglia lesions affect
the contralateral
what do lesions of the basal ganglia cause
muscle tone change
dyskinesia eg tremor, chorea, myoclonus
what is myoclonus
muscle jerks
what is chorea
rapid, asymmetrical movements (usualy affect distal limb musculature)
What diseases affect the basal ganglia
Parkinsons- substansia nigra
Huntingons- basal ganglia and cerebral cortex degeneration
what symptoms are associated with parkinson
akinesia
rigidity
resting tremor
what symptoms characterise huntingtons
chorea
dementia
