Physiology of Voluntary Motion

Question 1

What input pathway allows for motor acts based on visual input?

Answer 1

Dorsal visual pathway, form the occipital cortex to the parietal/frontal cortex.

Question 2

Where specifically is visual information sent to in the parietal cortex? What does this accomplish?

Answer 2

V6A or the VIP. Creates a rough map of the space around you.

Question 3

Where is information sent from the VIP area? What does this accomplish?

Answer 3

To F4 or the premotor cortex. Creates a detailed map of the space around you.

Question 4

What is the second pathway that is working with the detailed mapping pathway to help with voluntary motion?

Answer 4

From VIP to F2 in the premotor cortex to create information about where your arm is when reaching.

Question 5

What does the Anterior intraparietal area and the PFG neurons respond to?

Answer 5

Seeing an object to grasp, Grasping an object and both actions.

Question 6

Where do neurons within the F5 region get their information, and what is the purpose of firing these neurons?

Answer 6

From PFG and Anterior intraparietal area. F5 fire with the Goal of the action.

Question 7

When would F5 neurons be active? When holding coffee with different grasps to while drinking it or while holding coffee with the same grasp with different intents?

Answer 7

Different Grasps with same goal. F5= Goal.

Question 8

Summarize what the Pre-motor cortex does in terms of voluntary motion.

Answer 8

Receives information required to move, determines whether it is appropriate to move and identifies the purpose of the motion.

Question 9

Summarize what the Supplementary motor cortex does in terms of voluntary motion.

Answer 9

It is the postural control area, the Pre-SMA plans the motor program required to make the action happen. SMA organizes and acquires motor plans.

Question 10

How is the Primary Motor Cortex organized and why is this important?

Answer 10

Arranged in columns and each column produces a specific movement.

Question 11

Which Layer of the Primary Motor Cortex receives sensory input?

Answer 11

Layer 4 (proprioception)

Question 12

Which Layer of the Primary Motor Cortex sends sensory output?

Answer 12

Layer 5 (CST)

Question 13

What are the two types of columns seen in the Primary Motor Cortex?

Answer 13

1- On/Off agonist Muscle

2- On/Off antagonist muscle

Question 14

What are the roles of the cerebellum in Voluntary muscle movement? (4)

Answer 14

Sequencing complex actions, correct force and direction, balance and eye movements, Learning complex actions

Question 15

What do the two regions of the Spinocerebellum control?

Answer 15

Central- Postural Control

Lateral- Force and Direction

Question 16

What does the Cerebrocerebellum control?

Answer 16

Planning complex motions

Question 17

What does the vestibulocerebellum control?

Answer 17

Balance and eye movements

Question 18

What are the inputs of the central region of the spinocerebellum?

Answer 18

Vestibular, Visual and Auditory and an efferent copy of what muscles get.

Question 19

Where are the outputs of the central region of the spinocerebellum sent?

Answer 19

Interpositus n, Fastigial n, to rubrospinal tract

Question 20

What are the inputs of the lateral regions of the spinocerebellum?

Answer 20

Muscle afferents, and an efferent copy of what muscles see.

Question 21

Where do the outputs of the lateral regions of the spinocerebellum go?

Answer 21

Interpositis nucleus and rubrospinal tract.

Question 22

What are the inputs of the cerebrocerebellum?

Answer 22

All regions of the cerebral cortex

Question 23

Where are the outputs of the cerebrocerebellum sent to?

Answer 23

Dentate Nucleus and back to the Cortex.

Question 24

Where are the inputs of the Vestibularcerebellum sent from?

Answer 24

From vestibular apparatus

Question 25

Where are the outputs of the vestibularcerebellum sent to?

Answer 25

Fastigial nucleus, vestibular nuclei

Question 26

What does the SNPC release to the striatum and what is the effect?

Answer 26

Releases dopamine and can excite the direct pathway or inhibit the indirect pathway.

Question 27

Describe the steps of the Direct Pathway, noting the Neurotransmitters.

Answer 27

SNpc-> Dopamine to Striatum
Striatum-> GABA to SNPR
SNPR->GABA to Thalamus

Question 28

Describe the steps of the Indirect Pathway, noting the Neurotransmitters.

Answer 28

Striatum-> GABA to GPe
GPe-> GABA to Subthalamic N.
Subthalamic N-> EAA to SNPR
SNPR-> GABA to Thalamus

Question 29

How does activation of the indirect and direct pathways affect motion, respectively?

Answer 29

Direct- allows motion

Indirect- Opposes motion

Question 30

How is the Indirect Pathway activated?

Answer 30

Intrastriatal Cholinergic pathway or EAA from the cortex

Question 31

What are the four needed areas to plan a complex motor act?

Answer 31

Frontal association area, Supplemental motor cortex, premotor cortex and the cerebrocerebellum.

Question 32

How does the brain go about activating motion in the muscles? (think fibers)

Answer 32

Activates Alpha Motor Neurons and uses the Gamma motorneurons to change the sensitivity to stretch. It also must inhibit alpha and gamma motorneurons in the antagonist muscle.

Question 33

Once the muscle fibers have been activated and inhibited to make a motion happens, what is involved to make sure the motion is correct?

Answer 33

Spinocerebellum. (from muscle to cerebellum)