Voluntary motion Flashcards
there are several cortical areas associated with the production of voluntary motion. What are?
the primary motor cortex, supplementary motor cortex, premotor cortex, parts of the pre-frontal cortex, and the parietal cortex
what is the primary role of the premotor cortex regarding voluntary motion?
it identifies the intent of the motion and decides what motion to produce
what are the two divisions of the supplementary motor cortex?
the supplementary motor area (SMA) and the pre-supplementary area
what is the role of the SMA?
postural control
what is the role of the pre-SMA?
plans the motor program required to make the action occur “what needs to happen in what order”
if a plan is not working to open something or achieve a goal, what area is in charge of switching up the plan?
the supplementary motor cortex
where is the primary motor cortex located?
in the pre-central gyrus
what is the role of the primary motor cortex?
it controls specific movements, especially those related to moving the arms/ hands to the face/ mouth
how is the primary motor cortex arranged?
into columns
what layer of the neocortex receives sensory input?
layer 4
where is the sensory input into layer 4 coming from?
muscle and joint proprioception
which layer is the output for the corticospinal (pyramidal) pathway?
layer 5
there appear to be two sets of neurons in each column. What are they?
one to start the motion and one set to maintain it as long as necessary
neighboring columns in the primary motor cortex control what?
related motions not neighboring muscles
there seems to be 2 kinds of columns. What are they?
- on/off for the agonist muscle 2. off/on for the antagonist muscle
which cortical region determines whether it is “okay” to move and identifies the goal and the motion required to meet that goal?
the premotor cortex
what cortical region is responsible for postural controls, identifying the specific motor sequences required, and changes tactics if necessary?
the supplementary motor cortex
what cortical region is responsible for coding the individual motions that are required to reach the goal?
the primary motor cortex
where is the supplementary motor cortex relaying the information?
to the primary motor cortex
from the visual cortex, the visual information coming up the dorsal pathway is going to be relayed where? reaching
to the parietal cortex–> specifically V6A, and the caudal area of the paretal cortex (PEc), medial intraparietal area (MIP) and the ventral intraparietal area (VIP)
what area creates the rough map of the space around you?
the ventral intraparietal area (VIP)
from the VIP where is the information sent?
to F4 within the premotor cortex
What does F4 do with the information?
it creates a detailed map of the space around you
what are neurons in the F4 region particularly excited by?
proximity ( the closer the object is, the more they fire)
what gives me the map of the body (arm in space)
F2 in the premotor cortex
the anterior intraparietal area (AIP cortex) and PFG relay their information where?
to F5 (part of the premotor cortex)
Neurons in F5 fire due to what?
the goal of the action, not the motor act itself
What is the area of parietal cortex required for grasping?
AIP cortex and PFG
what is the area of parietal cortex required for reaching?
V6a, PEc, MIP, and VIP
Which part of the brain encodes a motor act?
primary motor cortex
what is the role of the cerebellum?
sequence complex actions, correct force/direction, balance and eye movements, learning of complex actions
the spinocerebellum is responsible for what?
postural control
the lateral spinocerebellum is responsible for what?
feedback control of on-going motion ballistic motions/ force and direction
the cerebrocerebellum is responsible for what?
planning complex motions and learning
the vestibulocerebellum is responsible for what?
future balance and eye movements
the spinocerebellum receives input from where?
efferent copy, vestibular, visual and auditory input
the lateral spinocerebellum receives input from where?
efferent copy and muscle afferent information
the cerebrocerebellum receives input from where?
cerebral cortex related to motion
the vestibulocerebellum receives input from where?
vestibular apparatus
the spinocerebellum has output to where?
the interpositus and the fastigial nucleus and to the rubrospinal tract
the lateral spinocerebellum has output to where?
the interpositus nucleus and to the rubrospinal tract
the cerebrocerebellum has outputs to where?
dentate nucleus and back to cortex
the vestibulocerebellum has outputs where?
vestibular nucelus
What is responsible for the motions of walking, breathing, and chewing?
the central pattern generators (CPGs)
in actions such as walking, breathing, and chewing, what is influencing the alpha-motor neurons?
the CPG
does the CPG require sensory input?
no it can work in the absence of it
what is the role of the basal ganglia?
they control the beginning and end of movement
where do you start in the direct pathway of the basal ganglia?
in the striatum
what makes up the striatum?
the caudate nucleus and the putamen
where do the axons from the striatum project to in the direct pathway?
the SNPR/GPi
where do the axons from the striatum project to in the indirect pathway?
to the GPe
where do the axons from the GPe project to in the indirect pathway?
to the subthalamic nucleus
where do the axons from the subthalamic nucleus project to in the indirect pathway?
to the SNPR/GPi
to produce motion, what must we do?
activate the direct pathway and inactivate the indirect pathwat
what NT is present to activate the direct pathway/ inactivate the indirect pathway?
dopamine
what receptor is found on the neurons in the striatum that are involved in the direct pathway?
D1
what receptor is found on the neurons in the striatum that are involved in the indirect pathway?
D2
what is the source of the dopamine in the basal ganglia?
the substantia nigra pars compacta
what is abolished in parkinson’s disease?
the SNPC input
What do we use to activate the indirect pathway?
EAA and acetylcholine
