Motor Systems Flashcards
3 Major types of movements
Feedforward anticipatory response consists of
Coactivation of bicepsand tricepts before movement even began
Feedback or compensatory change consists of
Stretch reflex that keeps both extensor and flexor activate to maintain position
What are the 3 levels of hierarchy in the motor system
All 3 motor system levels are under influence by what two structures
2 subcortical systems the basal ganglia and the cerebellum
What is the lateral medial organization of the
Function of propriospinal interneurons.
Which are long and which are short
Motor second level medial descending pathways consist of
VEstibulospinal, reticulospinal, tectospinal
Medial descending pathways critical for?
Bilateral or ipsilateral innervation?
Motor Level 2 (brainstem) - Function of lateral descending pathway?
Which Tract?
Cortex Ventral coticospinal tract
originates?
What does it mainly control?
terminate bilaterally or ipsillateraly
Area 6 and some 4,terminate bilaterally, Mostly Trunk
UNCROSSED
Cortex Lateral corticospinal tract
originates?
terminates
Originates in 4,6 and somatosensory 1,2,3. CROSSES, contralateral innervation. Ends on spinal grey matter and the medial portion of dorsal horn.Als collaterals to dorsal column nuclei
General organization of somatosensory and motor cortex topographic map
Limbs and trunk (Feet - hands)
Face to tongue
What are the cortical inputs to the primary motor cortex
What are the primary inputs of the premotor areas
The Motor cortex receives indirect stimulation from?
Population Encoding?
How does plasticity occur in motor maps
Activity in individual neurons of primary motor cortex is related to
muscle force not movement amplitude
Compex movements are initiated
internally by SMA
Movement by external sensory stimuli involve
lateral Premotor areas
Neuronal activity represents
M1
SMA
LatPreM
Just thinking and plannig a movement involves the
How do lateral premotor neurons fire in response to spatial cues
They respond by firing before the action and through action, signal relative to spatial location
What are mirror neurons
Role of Feedforward vs Feedback
3 Tracts involved in feedforward
3 information sources for feedback
Normal Postural response requires?
3 Tracts of the Medial Motor System
2 Phases of the step movement
During walking opposite limb step phases overlap during what phase?
Basic organization of neural control of locomotoin - what generates the rhythm of walking
Common feature of most CPG organization is?
What is meant by half-center circuit in locomotion
THe flexor and extensor modules have reciprocal innervation and therefore function alternatively
Location of CPG in brainstem and one possible candidate neuron
Key areas in descending control of spinal locomotor CPG
cortex - Mesencephalic locomotor region - medullary reticular formation - Reticulospinal tract - CPG
What change in signal regulates locomotor speed and pattern
How is visual information routed to incorporate in locomotion (stepping)
Why does postural support help recovery after spinal cord injury
3 Factors in Cerebellum Lesion - 2 things that occur and 1 thing that will not occur
3 Lobes of the Cerebellum
3 Functional divisions
Anterior, posterior, floculonodular
vermis, lateral, intermediate
2 Input systems of the Cerebellum
Climbing fibers and moss fiber-parallel
Climbing Fibers
orgin and terminate
How many climbing fibers per purkinje
inferior olive - dendrites of purkinje cells
each purkinje gets 1 climbinig fiber but one climbing fiber contacts many purkinje
Mossy Fiber
origin - terminate
many sensory modalities - terminate on granule cells
Parallel fibers orginate from - what do they contact
are the axons of granule cells contact purkinje cells
Vestibulocerebellum
- axons to?
- function
to vestibular nuclei
balance and eye movement
cerebrocerebellum (lateral hemispheres)
output to -
function
to dentate nucleus - motor and premotor cortices
motor planning
Intermediate Hemisphere
output to
function
Interpose nuclei - lateral descending systems
motor execution
Vermis
output to
function
fastigial nuclei - medial descending system
Motor execution
How many somatosensory maps in cerebellum
HOw is it distributed in spinocerebellum
3 mecahno and proprioceptive somatosensory maps
limbs intermediate axial is vermis
Axial and Limb modification pathways from spinocerebellum
Cerebrocerebellum path to impact before movement
anticipatory control of limb movement
What happens if you take out the cerebellum
overshooting and oscillation without the cerebellum
How is cerebellum incorporated in more cognitive demants
(grabbing an item vs identifying and grabbing it)
Cerebellar involvement in motion learning
3 Main categories of cerebellar symptoms
