Basal Ganglia and cerebellum Flashcards
What is the role of both the basal ganglia and cerebellum?
They both improve the accuracy of movement by creating loops with the motor and sensory areas of the cerebral cortex and impact the upper motor neurons.
What is the effect of damage to the cerebellum?
Uncoordinated gait with ataxia
What is the effect off damage to the basal ganglia?
Issues with speech, movement and posture.
What is the cerebellum?
It is a structure in the hind brain that contains 50% of all neurons in the CNS. It has a high surface area due to its folia and lobules.
What is the function of the cerebellum?
It co-ordinates muscles for balance and muscle tone and movement. It has a comparator function by modifying motor movement for accurary based on sensory input from the cortex. It is responsible for motor memory of muscles.
What is the vestibulocerebellum?
It consists of the flocculus and the nodules. Receives input from the vestibular nuclei. Controls the muscles for balance.
What is the spinocerebellum?
Receives input from the spinal cord. Lateral part controls distal muscles and medial portion controls axial muscles.
What is the cerebrocerebellum?
Receives input from the cerebral cortex and responsible for skilled movement such as speech.
What are the peduncles?
Stalks which connect the cortex to the midbran. Consists of the superior, middle and inferior cerebellar peduncles.
What is the superior cerebellar peduncles?
They are an efferent pathway which arises from the white matter of the cerebellum to act on the red nuclei and thalamus. This includes communication with the dendate nuclei for motor execution control.
What is the middle cerebellar peduncles?
They are an afferent pathway which arises from the pons. The pons has a relay neuron that receives input from the cerebrum to communicate motor input to the cerebellum. It is contralateral because it decassates and allows motor input for movement.
What is the inferior cerebellar peduncles?
They are both an afferent and efferent pathway. They allow communication between the spinal cord and medulla oblaganta to the cerebellum to allow for sensory input such as propioception to modulate.
What is the motor input into the cerebellum?
Middle cerebellar peduncles.
What is the sensory input to the cerebellum?
Inferior cerebellar peduncles.
What is the inferior olive?
Part of the medulla oblaganta that communciates to the cerebullum motor timing and planning.
What is the deep cerebellar nuclei?
Imbedded structures in the white matter which are the main ouputs from the cerebellar cortex to the midbrain and cerebral cortex.
What is the ventral lateral complex?
Thalamus which receives input from the cerebellum and midbrain to project onto the cerebral cortex and influence movement.
What is the output to the cerebellum?
Deep cerebellar nuclei.
What is the role of the fastigial nuclei?
Cerebellar nuclei of the archicerebellum which creates a lateral descending pathway to control motor execution.
What is the role of the intersposed nuclei?
Cerebellar nuclei of the spinocerebellum which creates a medial descending pathway to control motor execution.
What is the role of the dendate nuclei?
Cerebellar nuclei of the cerebrocerebellum which is involved in motor plannning.
What is the vestibular nuclei?
Group of 4 nuclei present in the pons, medulla and the flocculonodular lobe that is involved in balance and gait.
What cells are present in the cerebellar cortex?
Glial, granule, stellate and golgi cells which act as the interneurons for mossy fibre afferents.
What is the input to the cerebellar cortex?
Via either the mossy fibres or the climbing fibres.
What is the output to the cerebellar cortex?
Purkinje fibres which act on the deep cerebellar nuclei by releasing the inhibitory neurotransmitter GABA to reduce action.