Lecture 07 - Motor Control
🧠 movement is a complex orchestra of parts of the brain that work together to coordinate the
movement thoughtfully and effectively
○ basal gangliainitiates and switches between difftypes of movements
○ parts of theassociation cortex(especially thoseimportant for working memory) help
keep in mind what to do
■ to translate that idea into a set of motor actions
Joint Articulation
🧠 looking at muscle contractions is important when looking at movement
🧠 electromyography(EMG) is used to measure muscle contraction
○ similar to EEG
■ EMG→ measures signals in thebody/muscles
■ EEG→ measures signals in thebrain
○ electrodes are placed on particular set of muscles
■ measuresextent to which theycontract / relax
🧠 manygroups of musclesact inopposition to each other(antagonist pairs)
○ i.e. biceps and triceps
■ when the bicep is extended the tricep is relaxed; vice versa
Neuromuscular Junction
🧠 motor neurons communicate w/ muscles fibers
based on what the individual wants to move
○ communication is done through
neurotransmitter,acetylcholine (ACH)which
causes muscle to contract
○ relevant motor neurons contract relevant muscle
for particular movement
🧠 muscle fibers are the interphase for CNS and the body
○ controls the carrying out of wishes and goals in the environment
🧠 under typical circumstances, releasing ofACH causesmuscle contraction[controlled
movement]
○ careful synergyof how ACH operates between the motorneuron and muscle fiber
○ important the process is tightly regulated for careful contraction to desired extend and
to relax when needed
🧠 # of conditions that could jeopardize the process
○ botox
■ used for relaxing muscles
, ■ blocks ACH receptors → forcing relaxation
○ black widow venom
■ causes hyper release of ACH
■ uncontrolled ACH release → uncontrolled movement
● muscle spasms
● contractions
● death [some cases]
● affect motor neurons that control breathing
○ Myasthenia Gravis
■ medical condition characterized by “grave muscle weakness”
■ ACH receptors are much less effective
● not optimal for operation
■ chronic challenge to control movement
■ illustrates the proper balance of ACH between motor neurons and muscles fibers
Signaling Between the Body and the Spinal Cord
🧠 the spine primarily carries two kinds of information
○ motor informationto control motor signals
○ somatosensory informationfrom body to carry to thebrain
🧠 somatosensory input → afferent signals
○ body to brain
🧠 motor output → efferent signals
○ brain to body
🧠 complex actions [a kick to knee] only needs a handful of neurons, doesn’t necessarily have
to be sent to brain
⭐ think input above and output bottom
Major Motor Pathways
🧠 two kinds of tracts
○ pyramidal tract
🧠 movement is a complex orchestra of parts of the brain that work together to coordinate the
movement thoughtfully and effectively
○ basal gangliainitiates and switches between difftypes of movements
○ parts of theassociation cortex(especially thoseimportant for working memory) help
keep in mind what to do
■ to translate that idea into a set of motor actions
Joint Articulation
🧠 looking at muscle contractions is important when looking at movement
🧠 electromyography(EMG) is used to measure muscle contraction
○ similar to EEG
■ EMG→ measures signals in thebody/muscles
■ EEG→ measures signals in thebrain
○ electrodes are placed on particular set of muscles
■ measuresextent to which theycontract / relax
🧠 manygroups of musclesact inopposition to each other(antagonist pairs)
○ i.e. biceps and triceps
■ when the bicep is extended the tricep is relaxed; vice versa
Neuromuscular Junction
🧠 motor neurons communicate w/ muscles fibers
based on what the individual wants to move
○ communication is done through
neurotransmitter,acetylcholine (ACH)which
causes muscle to contract
○ relevant motor neurons contract relevant muscle
for particular movement
🧠 muscle fibers are the interphase for CNS and the body
○ controls the carrying out of wishes and goals in the environment
🧠 under typical circumstances, releasing ofACH causesmuscle contraction[controlled
movement]
○ careful synergyof how ACH operates between the motorneuron and muscle fiber
○ important the process is tightly regulated for careful contraction to desired extend and
to relax when needed
🧠 # of conditions that could jeopardize the process
○ botox
■ used for relaxing muscles
, ■ blocks ACH receptors → forcing relaxation
○ black widow venom
■ causes hyper release of ACH
■ uncontrolled ACH release → uncontrolled movement
● muscle spasms
● contractions
● death [some cases]
● affect motor neurons that control breathing
○ Myasthenia Gravis
■ medical condition characterized by “grave muscle weakness”
■ ACH receptors are much less effective
● not optimal for operation
■ chronic challenge to control movement
■ illustrates the proper balance of ACH between motor neurons and muscles fibers
Signaling Between the Body and the Spinal Cord
🧠 the spine primarily carries two kinds of information
○ motor informationto control motor signals
○ somatosensory informationfrom body to carry to thebrain
🧠 somatosensory input → afferent signals
○ body to brain
🧠 motor output → efferent signals
○ brain to body
🧠 complex actions [a kick to knee] only needs a handful of neurons, doesn’t necessarily have
to be sent to brain
⭐ think input above and output bottom
Major Motor Pathways
🧠 two kinds of tracts
○ pyramidal tract
