Voluntary Motion Flashcards
1
Q
- Function of dorsal visual pathway in the production of voluntary motion
A
- Travel from occipital cortex to parietal/frontal cortex
- enables us to complete motor acts based off of visual input
- Allows us to reach and grasp for objects
2
Q
From the visual cortex, information is sent to what areas in the parietal cortex?
What is the function of each of these areas?
A
- V6A
- PEc
- MIP
- VIP-creates rough map of space around you
3
Q
- From the VIP, information is sent to _ within the premotor cortex
- This area gives us information about?
A
- F4
- Creates a detailed map of space around you
- Neurons in F4 are excited by proximity
- F4-surroundings and floor
4
Q
- From the VIP, information can also be sent to _ (which is located in the premotor cortex and perceives where your body is in relation to what is around you)
A
- F2-where are you
5
Q
- Functions of neurons in the anterior interparietal area and PFG
A
- Seeing an object to grasp (visually dominant neurons)
- Grasping an object (motor dominant neurons)
- Both seeing and grasping an object (visuomotor neurons)
6
Q
- Neurons from the anterior intraparietal area and PFG relay their information to _ (located rostral to the premotor cortex)
- What is the function of this area?
A
- F5
- Neurons in F5 fire with GOAL of action, not motor action itself
- F5-with goal in mind
7
Q
- Functions of the premotor cortex
A
- Receives sensory info required to move (F4 and F5 in particular)
- Applies rules that it is appropriate to move
- Identifies the intent of the motion and decides which motion to produce
8
Q
- What are the two divisions of the supplementary motor cortex
- What are their functions of the subdivisions
- What is the overall function of the supplementary motor cortex
A
-
Supplementary motor area
- Postural control
-
Pre-SMA
- Plans motor program required to make action occur
-
SMC as a whole
- Organize motor sequences
- Acquire motor skills
- Executive control (switch actions/alter strategies)
9
Q
- Primary motor cortex functions/characteristics
A
- Precentral gyrus
- Controls specific movements
- Regions of body that do fine motions have proportionally high representation
- Arranged in columns (more columns in areas of brain that require fine motor movements)
10
Q
If we are in an area that controls a fine motion, stimulation may produce contraction of _
If we are in an area that controls general motion, stimulation may produce contraction of _
A
- Single muscles
- Group of muscles
11
Q
- What is the input layer of the primary motor cortex?
- What is the output layer of the primary motor cortex? (To which pathway does this travel?)
A
- Layer IV receives input (muscle and joint proprioceptors amongst others-need to know where we are in space to determine how we will execute a specific movement)
- Layer V-Corticospinal pathway (LMNs)
12
Q
- What are the functions of the two sets of neurons in the primary motor cortex?
A
- One set of neurons starts the motion
- One set of neurons maintains the motion
13
Q
- Neighboring columns control _
A
- Related motions
14
Q
- What are the two types of columns
A
- On/off for agonist muscle
- On/off for antagonist muscle
15
Q
- Role of cerebellum
A
- Sequence complex actions
- Correct force/direction
- Balance and eye movements
- Learning of complex actions
16
Q
- What are the three functional divisions of the cerebellum
A
- Vestibulocerebellum
- Spinocerebellum
- Cerebrocerebellum
17
Q
- What are the two areas of the spinocerebellum
- What are the functions of each area
A
- Vermal and paravermal regions
-
Vermal region
- Postural adjustments to ongoing motions
-
Paravermal regions
- Correct ongoing motions
- Control ballistic motions
18
Q
-
The vermal region of the spinocerebellum
- Inputs
- Outputs
A
-
Inputs
- Vestibular
- Visual and auditory
- Efferent copy (what brain sends to muscle)
-
Output
- Interpositus n
- Fastigal n
- Rubrospinal tract
19
Q
-
The paravermal region of the spinocerebellum
- Input
- Output
A
-
Input
- Muscle afferent
- Efferent copy (what brain sends to muscle)
-
Output
- Interpositus n.
- Rubrospinal tract
20
Q
- Location and function of the cerebrocerebellum
A
- Lateral cerebellum
- Plan complex motion
- Sequence of motions
21
Q
- Cerebrocerebellum
- Inputs
- Outputs
A
-
Inputs
- All regions of the cerebral cortex
-
Outputs
- Dentate
- Back to cortex
22
Q
- Function of the vestibulocerebellum
A
- Future
- Balance/Eye movements
23
Q
-
Vestibulocerebellum
- Inputs
- Outputs
A
-
Inputs
- Vestibular afferents (direct or indirect)
-
Outputs
- Fastigal n. to vestibular nuclei
- Ascend or descend
24
Q
- What are the deep cerebellar nuclei
A
- Dentage
- Fastigal
- Interpositus
- Globose
- Emboliform
25
Q
- To produce a motion, what must occur? (Generally speaking)
A
- Stimulation of the direct pathway
- Inhibition of the indirect pathway
26
Q
- What needs to occur to prevent a motion from occuring (Generally speaking)?
A
- Inhibit the indirect pathway
27
Q
- How does dopamine affect the direct and indirect pathways?
- What type of dopamine receptors are present in each pathway?
- End results?
A
- Dopamine
- D1 receptors on direct pathway
- Excited by dopamine
- ALLOWS motion
- D2 receptors on indirect pathway
- Inhibited by dopamine
- Excited by EAA/ACh
- INHIBITS motion
- D1 receptors on direct pathway
28
Q
- D1 and D2 receptors are located in the _
- Stimulated or inhibited by dopamine released from the _
A
- Striatum
- SNPC (Substantia nigra pars compacta)
29
Q
- Describe the direct pathway
A
- SNPC released dopamine
- Activation of D1 receptors on striatum (INFLOW)
- Increased release of GABA from the striatum onto cells of the SNPr and GPi (OUTFLOW)
- Decreased activity of SNPr and GPi leads to decreased release of GABA from these areas onto the thalamus
- Less GABA released onto thalamus, more activity of thalamus
- Thalamus releases EAA onto cortex
- Allows motion to occur
30
Q
- Describe the INACTIVATION OF indirect pathway
A
- SNPC releases Dopamine
- Dopamine binds D2 receptors on the striatum
- Morew GABA released from Striatum onto GPe
- GPe more active, and releases less GABA onto the subthalamic nucleus
- More activity of subthalamic nucleus
- More release of EAA from subthalamic nucleus onto SNPR and GPi
- More GABA released from SNPR and GPi onto thalamus
- Decreased release of EAA from thalamus to cortex
- NO MOTION
31
Q
- Function of basal ganglia
- How does it perform its function
A
- Control beginning (and end of movement)
- Inhibiting and withdrawal of inhibition (to prevent and allow movement to occur)
32
Q
- What areas of the brain are important for planning of a complex motor action
A
- Frontal association area
- Supplementary motor cortex
- Premotor cortex
- Cerebrocerebellum
33
Q
- Interactions between what areas of the brain determine if motion will occur?
A
- Interactions between frontal, premotor, SMC, and basal ganglia
34
Q
What happens once the appropriate columns in the primary motor cortex are activated?
A
- APs travel to activate alpha motor neurons of the muscles needed to complete the action
- Also activates gamma motor neurons for spindles in the contracting (agonist m) (this is alpha gamma coactivation)
- INHIBITS alpha and gamma motor neurons for antagonist m
35
Q
- Once the motion has started, the _ is called upon to make sure the motion is correct
A
- Spinocerebellum
36
Q
- Describe the ACTIVATION of the INDIRECT pathway
- What is the result of activation of the indirect pathway
A
- Activation of the indirect pathway leads to NO MOTION
- Increased release of EAA or ACh onto indirect pathway cells in striatum
- Increased activation of indirect pathway neurons, leads to increased APs and GABA release onto GPe neurons
- Increased GABA release onto GPe neurons leads to IPSP and Decreased AP and release of GABA from GPe onto the Subthalamic nuclei
- Decreased GABA release onto subthalamic nuclei leads to depolarization and increased APs and release of EAA onto the SNPR/GPi
- Increased release of EAA onto SNPR and GPi increases AP and release of GABA from these areas onto the thalamus
- Increased release of GABA onto the thalamus leads to IPSP/Hyperpolarization and less EAA release from thalamus onto cortical neurons
- End result: No motion

37
Q
A