Motor areas, cerebellum and basal ganglia

Primary motor cortex, premotor cortex, supplementary motor area, cerebellum and basal ganglia: who plans, launches and adjusts movement.

The outline, topic by topic

Each topic is weighted the way the exam weighs it.

Primary motor cortex: what is it?
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The frontal-lobe area sending the command to the motor neurons.
Each body part has its zone: the motor homunculus.
Someone shakes when bringing a glass to their mouth and misses. Which structure is damaged?
- The cerebellum
- The visual cortex
- The lumbar cord
- The vestibule
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The cerebellum
Intention tremor is a cerebellar sign.
Premotor cortex: what is it?
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The area in front of the motor cortex preparing movements guided by the surroundings.
Catching a ball one sees coming.
Why does the motor homunculus give the hand a large area?
- Its muscles are the strongest in the body
- Its muscles have the largest motor units
- Its fine movements need many neurons
- Its nerves are the longest in the body
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Its fine movements need many neurons
Cortical area follows fineness of control, not size or strength: hand muscles have, on the contrary, many small motor units.
Supplementary motor area: what is it?
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The area organising learned movement sequences, started from within.
Linking a gymnastics routine.