Lecture 11 Review Flashcards
What is the function of the sensory motor system?
coordination of sensory input to organize motor output
What does the prefrontal cortex do?
using information from the post parietal cortex, it makes decision
sends commands to the secondary motor cortex via the basal ganglia
What activates the primary motor cortex?
once activated by the basal ganglia, the premotor and supplementary motor areas activate the primary motor cortex
produces precise pattern of specific regions of M1
What does the primary motor cortex do?
controls activation of motor neurons. stimulation = contraction of muscles
somatotopic mapping, distorted based on number of motor units
Describe the M1 cell activity vectors
individual neurons encode directional info involved in motor neuron pool activation during limb movement
cells are sensitive to direction, summer to give a population vector
some cells activated more depending on direction of movement
Describe the plasticity of motor maps
remapping of the M1 occurs when motor efferents are disrupted. change muscles they control
What are the lateral pathways?
lateral pathways: voluntary movements under direct cortical control
corticospinal tract: from neocortex to spinal interneurons
rubrospinal tract: from red nucleus in the brain to spinal interneurons
What are the ventromedial paths?
important for posture and locomotion
vestibular - coordinates vestibular information with motor control for balance
tectospinal - coordinates visual system with motor control. maps surrounds and orients response
What are the reticulospinal tracts?
also ventromedial paths, these are in charge of extensors in antigravity reflexes. coordinated by motor cortex
pontine reticulospinal - maintains posture via extensor muscle control
medullary reticulospinal - inhibits extensor muscle control
When is the premotor area activated?
prior to motor movements
is involved in planning of movement
What is the difference between learned and known behavior in brain activation?
the premotor cortex is highly activated when learning
increased sensorimotor areas when learned
What is the inter-cortical loop?
the loop in which the basal ganglia provides input from the prefrontal cortex to the secondary motor cortex through the Ventrolateral thalamus (VLo)
What is the basal ganglia’s function and circuitry
serves as a pathway between the prefrontal cortex to SMA/PMA
it goes from the PFC to striatum (excitatory)
striatum to globus pallidus (inhibitory)
globus pallidus to VL thalamus (inhibitory)
VLo to SMA (excitatory)
What is the indirect basal ganglia pathway?
the striatum receives inut from the substantia niagra
What is the cerebellum’s function in the motor loop?
it receives sensory input via the pons and projects to the thalamus (VLc), which relays information to the M1
it coordinates ongoing motor movement
