Week 13 - Cortical Motor Areas

Question 1

Complex/Volitional Movement

Answer 1

Motor output that is planned and refined by the motor cortex, basal ganglia and cerebullum

Question 2

Where is the red nucleus located?

Answer 2

Midbrain

Question 3

What cells are present in the red nucleus?

Answer 3

Rubrospinal cells

Question 4

What do rubrospinal cells do?

Answer 4

Activate localized synergies especially in the distal libs and face

Question 5

what are rubrospinal cells contrasted to?

Answer 5

Reticulospinal and vestibulospinal tracts that organise postural and locomotory synergies

Question 6

What do rubrospinal cells cross and where do they end up

Answer 6

They cross the midline and end up in the intermediate zone - not directly to motor neurons

Question 7

what do rubrospinal tracts descend in?

Answer 7

they descend in lateral white matter with corticospinal tract together in a way - because its also concerned with distal motor nuclei

Question 8

synergy

Answer 8

group of muscles contracting together for a specific purpose

Question 9

comparison of reticulospinal tracts synergies with rubrospinal tract synergies

Answer 9

reticulospinal tract synergies - widespread ( cover half the body) useful in generating postures
rubrospinal synergies - highly localized

Question 10

where is the motor cortex located

Answer 10

precentral gyrus

Question 11

descending axons - motor cortex-spinal cord
where do they go?

Answer 11

most of the descending axons from motor cortex to spinal cord (corticospinal) go to interneurons

Question 12

what type of organization does the motor cortex have

Answer 12

somatotropic organization
proportions based on number of motor neurons in the area

Question 13

where do axons with direct corticospinal synapses on motor neurons go?

Answer 13

distal limbs or speech motor nuclei

Question 14

how do motor cortex axons end up in the spinal cord

Answer 14

the motor cortex axons porject to the brainstem, it then crosses the midline and travels via lateral white matter and ends up in the spinal cord.

Question 15

multiple representation

Answer 15

single motor nuclei (muscles) represented in columns at many loci

Question 16

what is each column in

Answer 16

a different neigbourhood (different adjacent columns)

Question 17

what does each cortical locus represent

Answer 17

a different synergy; muscles which particpate in most synergies have the biggest representation

Question 18

what do muscle synergies depend on

Answer 18

personal experiences

Question 19

what is somethign that is also dependent on motor cortex synergies

Answer 19

language

Question 20

when are motor maps laid out

Answer 20

development and at very early stages

Question 21

what do thumb motor neurons have direct synaptic connections with

Answer 21

their corresponding neurons (thumbcorticomotorneural cells) in the motor cortex

Question 22

precision grip

Answer 22

eg. holding a pencil

Question 23

what happens to neural cells in motor cortex when precision grip is active

Answer 23

the neurons in motor cortex are active

Question 24

power grip

Answer 24

holding a ball

Question 25

what happens to neural cells in motor cortex when power grip is active

Answer 25

the neurons in motor cortex are inactive

Question 26

motor field

Answer 26

how one corticospinal axon synapses with a set of motor nuclei, in more than one spinal segment

Question 27

comment on activity of synapses in motor field

Answer 27

many synapses are silent

Question 28

what do motor field help with

Answer 28

plasticity

Question 29

only sensory input with direct access to motor cortex

Answer 29

propioceptors

Question 30

cutaneous input

Answer 30

comes from somatosensory association areas, related to postural and motion information

Question 31

premotor areas

Answer 31

they select motor cortical synergies into proper sequence for a given movement

Question 31

propioceptive input

Answer 31

direct from thalamus and from somatic association cortex

Question 32

what do premotor areas project to?

Answer 32

project into motor cortex but also with parallel routes to motor nuclei

Question 33

what role do premotor areas have

Answer 33

pattern generation role for learned highly evolved movements

Question 34

what sensory inputs does premotor cprtex process?

Answer 34

visual and auditory for cueing movment phases
eg. dorsal visual stream to dorsal half (spatial locations) and ventral visual stream to ventral half (object form –> shape of hand)

Question 35

what recognizes enviornmental cues

Answer 35

sensory association areas recognize the cues and forward the signal to the frontal lobe (prefrontal and premotor cortex)

Question 36

what triggers motor reactions

Answer 36

environmental cues

Question 37

broca’s area

Answer 37

premotor zone for sequencing language elements for speech or writing-typing

Question 38

where does brocas area get input from

Answer 38

wernicke’s area

Question 39

how does the premotor cortex help with responses

Answer 39

it selects appropriate response synergies in motor cortex

Question 40

preparatory activity

Answer 40

premotor neurons set up the motor cortex
not active during performance only active during the preparatoryphase

Question 41

what happens if there is a delay in preparatory activity

Answer 41

premotor neurons maintain acitivyt until a go cue is given

Question 42

where is the supplementary motor area located

Answer 42

medial wall of hemisphere

Question 43

representation of somatic motor area

Answer 43

somatotopic representation of body but less detail than motor cortex

Question 44

what does supplemetary motor cortex cotrol

Answer 44

bilateral coordination of limbs when different motions done on eahc side

Question 45

what does supplementary motor area process

Answer 45

internal volitional signals that drive movements

Question 46

where is the cingulate motor area located

Answer 46

singulate sulcus

Question 47

what does the cingulate motor area process

Answer 47

emotional nd motivational drive to movmeents