control of movement via cerebral cortex and other cortices

Question 1

cerebral cortex- primary motor cortex role in control of movement

Answer 1

primary motor cortex is involved in the execution of movement

• it is organised somatopically meaning a specific part of the body is associated with a distinct location
• its primary function is to generate signals that direct movements in the body
• it receives input from the frontal association cortex

Question 2

cerebral cortex- supplementary motor area role in control of movement

Answer 2

• needed for learning and planning behaviours consisting of sequences of movement

the pre SMA is associated with perception of control of spontaneous movements

both the SMA and pre SMA stimulation will promote the urge to make a movement or the anticipation that a movement will occur

Question 3

cerebral cortex- premotor cortex role in control of movement

Answer 3

• needed for learning and executing complex movements, learned patterns, or skills, or movements that require planning
• the premotor cortex is guided by sensory information
• it contains mirror neurons- found in frontal lobes, they fire neurons when you watch another person perform an action- so its important when learning a task

Question 4

The role of the basal ganglia-

Answer 4

Basal ganglia is important for voluntary movement

primary motor cortex, substantial Nigra, and primary somatosensory cortex sends input to striatal nuclei. this goes through various pathways and goes back into premotor cortex, primary motor cortex, supplementary motor cortex, and motor nuclei of the brain stem

Question 5

HUNTINGTONS DISEASE- disease involving the basal ganglia

Answer 5

Hereditary cause- degeneration of the striatal neurons in the caudate nucleus and putamen

symptoms- jerky limb movement’s, impaired ability to cease movement, cognitive and emotional change such as depression. difficulty with speech or swallowing

CAG DNA repeats causing toxic form known as mutant Huntington protein- this protein effects functioning of neurons which interferes with transport networks and gene regulation causing them to malfunction and die prematurely resulting in Huntington symptoms.

Question 6

control of movement via the cerebellum

Answer 6

The cerebellum has 2 hemispheres which function ipsilaterally
- its outer layer is tightly folded to increase SA and density of neurons (accounts for 50% of neurons in the brain)

FUNCTION- motor control functions. It smooths and integrates ongoing movement. is important for motor learning, independent rapid skilled limb movements, postural reflexes, balance

receives vestibular, auditory, visual info from motor and somatosensory cortices and sends it to every major brain structure.

Question 7

what happens if the cerebellum becomes damaged?

Answer 7

this can occur from a stroke, alcoholism, or a tumour

causing cerebellar ataxia= lack of coordinated muscle movements= difficulty walking and narrow base waling (one foot in front of another), posture, and balance

damage can also cause intention tremor- this is involuntary muscle contractions that occur during purposeful voluntary movement

Question 8

reticular formation role in muscle control

Answer 8

• has a large number of nuclei in the brainstem
• it is responsible for regulating muscle tone, controlling semi- automatic responses, and controlling posture, and playing a role in locomotion