Voluntary movement

Question 1

Cellular organization of the cortex in layers

Answer 1

I input
II input
III input (thalamus)
IV input (thalamus)
V major output 
VI output local

Question 2

where are the corticospinal neurons

Answer 2

layer V

Question 3

most stimuli activate several muscles (corticospinal axons diverge to motor neurons innervating more than 1 muscle)
simple movements of single joint
redundancy in muscle representation allows different combination of muscle activity for different tasks
Somatotopical organization (the homunculus)

Answer 3

primary motor cortex (M1)

Question 4

motor areas of the cortex associated with voluntary movements

Answer 4

primary motor cortex (M1)
premotor cortex (ventral, dorsal)
supplementary motor area
cingulate motor area

Question 5

areas for primary sensory cortex

Answer 5

3, 2, 1

Question 6

areas for secondary sensory cortex

Answer 6

5 and 7

Question 7

area for frontal cortex

Answer 7

46

Question 8

working memory and spatial relationships

Answer 8

frontal cortex

Question 9

Primary motor cortex properties

Answer 9

voluntary controlled movements (primarily simple mvmnts of hand and face)
somatotopic organization if highly plastic
Direct relationship b/w firing rate of M1 cells and force
Direction of movement is encoded by M1 neurons = population vector

Question 10

critical for planning movement
project largely to primary motor cortex but also directly to spinal cord
stimulation evokes more complex movements involving multiple joints and resembling coordinated movements
damage to any of these causes more complex motor deficits than damage to M1 alone

Answer 10

Premotor areas

Question 11

projects largely to proximal muscles

fires during delay between cue and actions

Answer 11

PMC d (dorsal)

Question 12

projects more to hand and digit muscles
hand to the correct shape for manipulating a specific object
active whether the subject watches or performs the task

Answer 12

PMC v (ventral)

Question 13

projects to M1 and SC

projections to SC largely to muscles of hand and digit

Answer 13

SMA

Question 14

SMA properties

Answer 14

sequential movements
mental rehearsal (internally driven movements)

Question 15

Stimulation of SMA evokes

Answer 15

bilateral movements

coordinates movements on the two sides of the body

Question 16

output pathways

Answer 16

corticospinal
corticobulbar
rubrospinal
tectospinal
vestibulospinal
reticulospinal

Question 17

largely controls voluntary movement and fine motor control

Answer 17

lateral corticospinal tract

Question 18

largely controls the neck and trunk

Answer 18

ventral corticospinal tract

Question 19

corticospinal tracts influence lower motor neurons via

Answer 19

direct excitatory connection to an alpha motor neuron

interneurons (which connect to alpha motor neurons) (excitatory - multijoint movements, inhibitory - modulate reflexes)

Question 20

rubrospinal originates

Answer 20

red nucleus

Question 21

rubrospinal crosses in

Answer 21

immediately in pons

Question 22

function of the rubrospinal

Answer 22

gross motor movements, primarily upper limb flexion

Question 23

vestibulospinal originates

Answer 23

medial- medial and inferior vestibular nuclei

lateral- lateral vestibular nuclei

Question 24

tectospinal originates

Answer 24

superior colliculus

Question 25

vestibulospinal funcitons

Answer 25

medial- controls head and back muscle to stabilize head;posture
lateral- activates extensor LMN to maintain upright and balanced posture

Question 26

tectospinal funciton

Answer 26

reflexive turning of the head

Question 27

function of reticulospinal

Answer 27

general movements; postural movements

Question 28

reticular formation

Answer 28

general alerting area of nervous system

Question 29

medial reticulospinal originates

Answer 29

pontine

Question 30

lateral reticulospinal originates

Answer 30

medullary

Question 31

descending spinal tracts; lateral pathways concerned with

Answer 31

goal directed limb movement

Question 32

descending spinal tracts; media pathways concerned with

Answer 32

postural control system

Question 33

UE flexion synergy components

Answer 33

scapular retraction/elevation or hyperextension
shoulder abduction, external rotation
elbow flexion
forearm supination
wrist and finger flexion

Question 34

UE extension synergy components

Answer 34

scapular protraction
shoulder adduction, internal rotation
elbow extension
forearm pronation
wrist and finger flexion

Question 35

LE flexion synergy components

Answer 35

Hip flexion, abduction, ER
Knee flexion
ankle DF inversion
toe DF

Question 36

LE extension synergy components

Answer 36

hip extension, adduction, IR
Knee extension
ankle PF, inversion
toe PF

Question 37

network of interneurons in brainstem and spinal cord
stringing together of reflexes; one triggering the next
rhythmic movements, adapted by higher brain centers

Answer 37

central pattern generators

Question 38

neurons with axons that descend from cerebral cortex or brain stem and end on lower motor neuron

Answer 38

upper motor neuron

Question 39

CN in brain stem or spinal cord and ends in skeletal muscles

Answer 39

Lower motor neurons

Question 40

spontaneous contractions of groups of muscle fibers visible through the skin as small twitches

Answer 40

fasciculations

Question 41

spontaneous contraction of individual muscle fibers, not grossly visible but apparent in electrical recordings

Answer 41

fibrillations

Question 42

a rapid series of alternating muscle contractions in response to sudden stretch

Answer 42

clonus

Question 43

UMN clinical signs

Answer 43

paresis
spasticity
Hypertonia
Hyperreflexia

Question 44

LMN clinical signs

Answer 44

Loss of reflexes
atrophy
flaccid paralysis
fibrilations/fasciculations