motor function

Question 1

motor control: what are high order areas of hierarchy involved in

Answer 1

more complex tasks e.g. programme and decide on movements, coordinate muscle activity

Question 2

motor control: what are lower order areas of hierarchy involved in

Answer 2

lower level tasks e.g. execution of movement

Question 3

motor system hierarchy

Answer 3

primary motor cortex and nonprimary motor cortex -> basal ganglia, cerebellum, brainstem and spinal cord -> basal ganglia to thalamus, cerebellum to thalamus and brainstem, brainstem to spinal cord and muscles of face, head and neck, spinal cord to muscles of body -> thalamus back to primary motor cortex and nonprimary motor cortex

Question 4

where does motor cortex receive information from and where does it send commands

Answer 4

receives information from other cortical areas, and sends commands to thalamus and brainstem

Question 5

what do the cerebellum and basal ganglia do

Answer 5

adjust comands received from other parts of motor control system

Question 6

what does the brainstem do

Answer 6

pass commands from cortex to spinal cord

Question 7

where is the primary motor cortex (MI), and how many layers does it have

Answer 7

precentral gyrus, rostral (anterior) to central sulcus, in frontal lobe; has 6 layers

Question 8

function of primary motor cortex (MI)

Answer 8

control fine, discrete, precise voluntary movement by providing descending signals to execute movement

Question 9

somatotropic organisation: Penfield’s motor homunculus diagram

Answer 9

homunculus inverted: anterior cerebral artery feed anterior motor area, which controls lower limb; not proportional (fine movements of hands, lips for speech etc. over-represented)

Question 10

where is the premotor cortex

Answer 10

frontal lobe anterior to MI

Question 11

function of premotor cortex

Answer 11

planning of movements by regulating externally cued movements (understanding of intra-personal and extra-personal space)

Question 12

where is the supplementary motor area

Answer 12

frontal lobe anterior to MI, medially either side of midline

Question 13

function of supplementary motor area

Answer 13

regulates internally driven planning and sequence of movements e.g. speech

Question 14

when does the supplementary motor area become active

Answer 14

when thinking about a movement before executing that movement (planning)

Question 15

2 brain areas that are not strictly motor areas as activity doesn’t correlate with motor output/act

Answer 15

posterior parietal complex, prefrontal cortex

Question 16

function of posterior parietal complex

Answer 16

ensures movements are targeted accurately to objects in external space (motor learning and motor planning, so don’t consciously think about these things e.g. getting dressed in morning)

Question 17

function of prefrontal cortex

Answer 17

involved in selection of appropriate movements for a particular course of action to prevent harm using previous experience (e.g. won’t touch a hot plate again)