Motor Control Flashcards
What is the highest level in the motor system?
The primary cortex
What does the primary motor cortex do?
It projects directly into the spinal cord via the corticospinal tract
It regulates the motor tracts that originate in the brainstem
What is the middle level in the motor system?
The brainstem
What does the brainstem do?
It is a laterally descending system which controls distal limbs and is important for goal-directed movements of the hand and arm
What is the lowest level of the motor system?
The spinal cord
What does the spinal cord do?
It controls neuronal circuits that mediate reflexes automatisms such as walking as well as many other actions
What is the symplest reflex?
mono-synaptic
Only involves one sensory neuron and one motor neuron
What haooens if you artificially stimulate the motor cortex, brainstem and spinal cord?
You only get twitches
What do lateral brainstem pathways control?
The hands and the arm
What do direct spinal cord pathways control?
Muscles and reflexes
What does the basal ganglia ‘loop’ back to and via what pathway?
It only feeds back to the motor cortex via the subcortical loop
What is the role of the basal ganglia and the cerebelllum?
They receive information from many different areas of the cortex and they project to the motor cortex
They are aware of situations a person is in and they monitor commands to the muscle to make sure they are appropriate for the situation
If commands are not appropriate then they calculate correct signals and send this to the motor cortex
What does the cerebellum feed back to?
Mainly the motor cortex but it can send signals down the brainstem and the spinal cord
When was the motor cortex discovered?
1870
In the mid 20th century electrical stimulation of the frontal lobes showed what?
There are specific motor effects depending on which site is stimulated in humans and primates