Neuro - MOTOR CONTROL 1

Question 1

which are the lateral pathways? which is the dominant one?

Answer 1

corticospinal tract (CST) and rubrospinal tract (RST). Corticospinal is the dominant one

Question 2

where do the lateral pathways decussate?

Answer 2

medula/ spinal cord junction

Question 3

2/3 of CST originates from which areas of the frontal motor cortex? what constitutes the last 3rd?

Answer 3

4 and 6, the last third is somatosensory

Question 4

if a lesion happens on the CST, what happens to the RST?

Answer 4

the functions lost with the lesion slowly start to re-appear because the RST takes over

Question 5

what do the lateral pathways control?

Answer 5

voluntary movements

Question 6

what do the ventromedial pathways control?

Answer 6

posture and locomotion

Question 7

which are the ventromedial pathways?

Answer 7

vestibulospinal tract (VST) and tectospinal tract (TST)

Question 8

what does VST do specifically?

Answer 8

stabilises head and neck

Question 9

what does TST do specifically?

Answer 9

ensures eyes remain stable as body moves

Question 10

where do the pontine and medullary reticulospinal tracts originate from?

Answer 10

brain stem

Question 11

what do the two reticulospinal tracts do?

Answer 11

REFLEXLY maintain balance and body position by innervating trunk and antigravity muscles in limbs

Question 12

how does the motor cortex directly activate spinal motor neurones and overrides reflex control?

Answer 12

by communicating via nuclei of ventromedial pathways

Question 13

which, of lower motor neurones or white matter tracts is somatotopic (= point-for-point correspondance between area of body and area of nervous system)

Answer 13

lower motor neurones (medial spinal cord is proximal limb muscles, lateral spinal cord is distal limb muscles)

Question 14

lateral white matter tracts get their information mostly from the cerebral cortex or brainstem?

Answer 14

cerebral cortex

Question 15

ventromedial white matter tracts get their information mostly from the cerebral cortex or brainstem?

Answer 15

brainstem

Question 16

where in the brain do the premotor areas lie compared to the primary motor cortex?

Answer 16

rostrally (closer to the nose) to the precentral gyrus

Question 17

which area number corresponds to the primary area cortex?

Answer 17

area 4

Question 18

what two types of area correspond to area 6? what do they do?

Answer 18

premotor area (PMA), supplementary motor area (SMA), they drive complex movements on either side of the body

Question 19

what does PMA do?

Answer 19

innervates distal motor units directly

Question 20

what does SMA do?

Answer 20

connects reticulospinal neurones innervating proximal motor units

Question 21

what areas a mental image of body in space using somatosensory, proprioceptive and visual inputs?

Answer 21

posterior parietal cortex, area 5 and 7

Question 22

which area number is considered the junction between ‘what actions are desired’ to ‘how the actions will be carried out’?

Answer 22

area 6

Question 23

which area number is active when thinking about performing an action?

Answer 23

area 6

Question 24

which area number is active when actually performing the action?

Answer 24

area 4