Class 17 - Motor system and cerebellum Flashcards
What are parts of the motor system?
Motor cortex, basal ganglia, cerbellum, brain stem, spinal cord, motor neurons
What does the posterior cortex do?
Specify movement goals and connect to prefrontal cortex
What does the prefrontal cortex do?
Generates movement plans
What does the premotor cortex do?
Recognizes movement of others and selects actions
What does the primary motor cortex do?
Executes movements
What do more complicated movements do to cerebral blood flow?
Increase the blood flow to many different regions
What happened when Wilder Penfield stimulated the precentral gyrus?
Produced movement in different parts of the body
How many homunculi are there in motor and premotor cortices?
10
What are the three types of organization in the motor cortex?
Part of body to be moved, spatial location to which the movement is directed, function
How do neurons increase force?
Increase firing
Are neurons able to plan and initiate movement?
Yes
Motor neurons calculate distance and direction of movement. True or false?
True
In imagined and active movement, is there similar brain activation?
Yes
What are mirror neurons?
Neurons that fire when we see others make a movement. They encode a complete action and fill in banks when part of a movement is absent
What hemisphere are mirror neurons generally located in?
Left hemisphere
What are the two ways the prefrontal and posterior cortex use sensory information?
Make movements in response to sensory stimulation.
Provide information to produce or modify complex movements.
What is deafferation?
Loss of sensory input (Friedreich’s ataxia)
What role does the basal ganglia have?
Modulate the force of movement
What are two disorders of too much movement?
Huntongton’s chorea and tourette’s syndrome. Cell death in caudate/putamen
What happens in Parkinson’s disease?
Loss of dopamine cells in substantia nigra causing muscular rigidity and difficulty performing movements
What are the two pathways in the internal globus pallidus?
Excitatory and inhibitory
What happens if the GPi is inhibited? excited?
Thalamus excitation and inhibition respectively
What does the cerebellum participate in?
Acquiring and maintaining motor skills
What does the flocculus do?
Takes part in balance