Flashcards
Motor behavior: nervous system and motor control
Cards in this deck (44)
- 1• Know the definition of motor behavior and its subsets (PPT slide). –• Motor learning: the acquisition of skills through: info processing, memory, practice organization (the parent field is cognitive psychology)
• Motor control: movement regulation, the different theories of control, and control systems
• Motor development: structure and function growth from kids→teens, neuromuscular function and biomechanical functions - 2o Sherrington:• 1900’s
• “law of effect”: activities and movements that are rewarded and repeated
• Origin of motor behavior analysis - 3Thorndike• 1900’s
• Original neurological findings
• “reflexes”, reciprocal inhibition, muscle spindle (MS) and golgi tendon organ (GTO) - 4o Bernstein• 1900’s
• Motor control theory (dynamical and hierarchical)
• “degrees of freedom”, problem/coordination
• Same time as Pavlov and the dogs
• We function based on reflexes (FALSE)
• Bernstein thought it was more complicated - 5• Brain and nervous system anatomy. Be able to identify the anatomical regions of the brain.o Nervous System can be divided into two main parts → CNS and PNS
• CNS: includes the brain and the spinal cord (ends around L1/L2)
• It follows two general pathways:
o Sensory: afferent neurons (occurs in the back of the brain)
o Motor: efferent neurons (front of the brain)
• Parts of the brain include different regions:
o Occipital: vision
o Temporal: auditory, memory, smell (this occurs outside the direct periphery)
o Parietal: main afferent lobe (really important for movement)
• Holds mechanoreceptors/proprioceptors
• Vestibular center
• Somatosensory: the main sensory receptive area for the sense of touch (before PMC)
o Frontal: main motor output (this includes movement and thought, and includes brain to body)
• Primary Motor Cortex: main reason for voluntary movement output (the senses come from other areas)
o Thalamus: relay center for all sensory information except for smell
• Brainstem: “primitive” function of survival
o Balance, HR, breathing, emotion, arousal (awake) **related to CPG location in the Mesenchephalon
• Cerebellum: mainly sensory - 6• PNS: can be subdivided into the autonomic and somatic nervous system• ANS: further divided into Sympathetic and Parasympathetic
o S: the “Fight or Flight” (3F’s in psychologists)
• The body is prepping for activity
o P: bringing back to normalcy, “Digest and Rest”
• SNS: voluntary action (originates from the α-motor neuron) - 7• What are the basic drives of human behavior? – What are the basic demands of movement?o Drives: the 4 F’s
• Feed
• Flee
• Fight
• Fornicate
• *Freeze* (this in more psychology settings)
o Demands: 3 basic demands
• Locomotion to seek or avoid→ seek survival, avoid danger, etc.
• Head Orientation
• Grasping - 8• Know basic function and anatomy of neurons.o Function: they are specialized cells of the NS called neurons; nerve fibers join in bundles called nerves to form a complex communication network that extends throughout your body
o Anatomy: (preferably look at the different pictures from the lectures if not then try to check your notes)
• Soma: cell body
• Axon hillock: where the AP begins has one of the highest concentrations of Na+
• Dendrites: branches that receive the AP from other neurons
• Axon: main road the AP travels on
• Nodes of Ranvier: the space b/w the myelin
• Myelin Sheath: protects the Axon and increase the speed of the AP
• Fatty substance developed from glial cells (supporter cells/non-propograting)
o CNS: oligodendrocytes→many neurons (branching)
o PNS: schwann cells→one neuron - 9• Be able to identify/draw an action potential and know the phases.o Look at the video
- 10• What is resting membrane potential? Why necessary?o Cell going back to its polar resting potential and this is necessary because it will allow for depolarization of the membrane which will lead to the action potential occurring
- 11• Depolarization, repolarization, hyperpolarization. Ions involved?o Depolarization
• When the charge becomes less negative and more positive
• Na+ ions flow into the voltage-gated channels (has a stronger positive charge than the K+ so it depolarizes the axon)
o Repolarization
• When the charge of the axon becomes negative again
• This occurs when the voltage-gated channels close and the amount of Na+ decreases and K+ opens to come back in (called the absolute refractory period where there is no more AP)
o Hyperpolarization
• There is too much K+ let in to the axon so its charge becomes overly negative (meaning a more polar charge) also known as the relative refractory period, but its brought back to normal by letting the K+ slowly diffuse out - 12• Axon membrane dynamics (depolarization, myelin, nodes of ranvier, ions)o Look at picture in notebook
- 13• What are EPSP/IPSP? – Two types of summation and how do they differ?o Excitatory Post-Synaptic Potential • The potential of the synapse to release neurotransmitters that allows for the AP to continue travel to the next synapse
o Inhibitory Post-Synaptic Potential
• Is the opposite, where the release of neurotransmitters prevents the AP from going to the next synapse
o Sum of all activities of pre-/post-synaptic to decide if the AP takes place
o Temporal
• The frequency of the firing
o Spatial
• Adding up all the summation - 14• Neurotransmitter Typeso Brain
• GABA: main inhibitory of the brain
• Glutanate: potent excitatory (concussions)
• ACh: needed for movement
• Dopamine: reward system of the brain
o Spinal Cord
• Glycine: inhibitory
• Aspartate: excitatory - 15• Neuromuscular physiology (be able to describe complete process of contraction) • Gross motor control vs fine motor controlo Gross: high number of muscle fibers per neuron, there are more neural connections, but the original signals meaning is lost
• 1000’s of fibers → quads
o Fine: few number of muscles per neuron, original signals meaning is same and consistent
• 10-100 fibers → hands/fingers - 16• Motor unit types and Recruitmento Determined by motor unit size, enzyme content, and protein content (myosin heavy chain isoforms)
o Slow fibers innervated by SMN (high SDH, low M-ATPase)
o Large fibers innervated by LMN (high M-ATPase, low SDH)
o Slow motor units
• SO (slow oxidative)
• Type I
• Small motor units
• Low M-ATPase
• Low threshold→easier for the Na/K flux but due to its size
• First recruited
o Fast motor units
• FOG (fast oxidative/glycolytic)
• Type IIa
• Larger MU
• Higher threshold (needs more energy for Na/K flux)
• FF (fast fatiguing/glycolytic)
• Type IIb
• Largest MU
• Highest threshold
• Last recruited
o Recruitment is the frequency of motor unit use and is directly related to the size and ease of triggering the AP in the soma. Different ways to increase recruitment include the henneman-size principle where the smaller motor units are recruited first and used more frequently; moreover, these patterns are additive (you still are using your SMU/Slow-fibers during a sprint which includes the LMU/Fast-fibers), and it is influenced by the force and power needed for the movement instead of s - 17• Central pattern generators (where, what, influences)o Neurons from the brainstem (midbrain), influence rhythmic movements that act automatically and independent of reflex activity and sensory feedback
• Ex.) locomotion, respiration, heart rhythm, defensive reaction (startle response)
o Influenced
• Afferent input (proprioception)
• “higher” center of control (frontal lobe)
• Neuromodulators/hormones (sex hormones - 18• Hierarchy of the nervous system (apply to motor development, control, and injury to brain)o Anatomically:
• Lv.1→brainstem “where life begins” includes the pons, medulla, and midbrain
• Lv.2→cerebellum
• Lv.3→cortex
o Developmentally: same as anatomically, except it starts from the bottom→back→front and it grows out. - 19• Receptors (types, function, importance for movement)o Thermoreceptors
• Temperature change
o Chemoreceptors
• Changes in blood and the digestive system
• Joints (inflammation ⇒ inflammatory response)
o Mechanoreceptors
• Muscle spindles
• deep muscle
• Golgi Tendon Organs
• Tendons
• Articular Receptors
• Joints
• Cutaneous Receptors
• Skin
• Meissener’s corpuscle
o Light touch
• Merkel’s disks
o Light pressure
• Pacinian corpuscle
o Deep pressure and vibration
• Ruffini endings
o Skin stretch, pressure
• Free Nerve Endings
• Pain all over - 20• Muscle spindle activity (describe, apply to daily activity and sport)o Deep muscle
o Relay sensory information from the muscle in parallel
o **focus on length (detected by the static nuclear bag an chain) of the muscle and the velocity of and length change (dynamic nuclear bag) **
o HAS CONSTANT PROPRIOCENPTION INPUT TO CNS - 21• Alpha-Gamma coactivation (apply to daily activity and sport)o The alpha-gamma coactivation is where the alpha-MN is causing a contraction to the extrafusal muscle fibers this causes the sensitivity to the Muscle spindle to decrease (because the length is shortening) resulting in gaps of somatosensory input, but while the alpha-MN is contracting the extrafusal fibers the gamma-MN is keeping the muscle spindle taught making it lengthened and more sensitive allowing for continuous somatosensory input.
- 22• Golgi Tendon functiono Innervates muscle tendon junction
o Sensors for force, stretch, and contraction
o High load, intense stretch/tension
o When the contraction increases it leads to inhibitions of movement - 23• Know and describe all reflexes and reflex arcso Check notebook
- 24• Neural Control of the Stretch-Shorten Cycleo At a certain height your cortex (executive function) will inhibit spinal reflexes and replace it with a feedforward mechanism that anticipates what jumping from the high height will feel like.
o In a sports level you don’t want the reflexive behaviors to be inhibited
• Feedforward mechanism
• The cortex inhibits reflexive activity b/c it happens at the same as voluntary
• Brain inhibits 1a afferent information at the spine so it cannot talk to the α-motor neuron (it does not inhibit the α-motor neuron b/c we still need it for muscle activity) - 25• Explain the importance of posture and balanceo Standing up straight and still
o “steady stance”
o Focusses on balance, energy efficiency, and mechanical loading
• Balance: looks at the effects of small bases and wide bases to maintain stability (when you put your feet together you sway but not that much)
• With people on the spectrum they have wider stances because of the cerebellar issues with balance
• Energy efficiency: stance you have is optimal for not using energy
• Can be altered by the center of gravity (COG, right in front of sacrum) any change in it causes a decr. energy efficiency
• Ex. Someone hunched over all the time spends more energy maintaining that stance than upright→less energy to use for other functions
• Mechanical loading: less muscle activity at rest
• Find some examples and more in-depth explanations - 26• Open vs Closed Loop Controlo Closed loop/Feedback
• Some sort of stimulus or change to the environment
o Open loop/Feedforward
• Automatic/adaptive/pre-programmed
• Preplanning of motor output (drop-jump-primary reflexes)
• EX.) postural responses (instinctually compensate your posture during movements) - 27• Motor Control Theories (reflex, hierarchical, motor program, dynamic systems)o Reflex
• Feedback control
• Movement in summation of reflex activity
• Withdrawal reflex
• Limitations is that it:
• does not predict voluntary movements
• does not predict movement absent of sensory stimuli
• does not explain predicted movement patterns
• reflexes can be inhibited
o Hierarchical
• Neuromaturational theory
• Phylogenic development of NS
• Higher centers inhibit lower centers (problems affect inhibition)
• You can see the difference in babies and adults
• If it occurs might be due to the presence of neurological disease
• Limitations: reflexes persist (focus on being feedback)
• Practical application: train or rehabilitate according to hierarchy
• Sit→crawl→stand→walk
• Supine→prone→kneel→stand→dynamic
o Motor Program
• Creating a burned motor patter in your brain (**once you know you know**)
• Innate or learned/feedforward
• Memory storage for a unique movement pattern
• Motor response schema is formed
• Two types:
o Recall: produces the movement after recall of movement parameters (motor memory)
o Recognition: (similar to efference copy), it does an ev - 28• Know functions of Vestibular systemo Semicircular canals detect head angle movements
o The otolith detects linear transitions
o Vestibular ganglion→vestibular nuclei→ cerebellum - 29• Motor development and skills (boys vs girls)o Once they hit that age cap young males start to outperform in throwing distance, speed of running, and long jump
o Young females surpass in balance control, flexibility, and accuracy
o Influences:
• Genetics:
• Constant throughout lifetime
• Represents the person’s blueprints and the potential they might have for performing certain actions
• Environment
• **key for motor skill learning at a young age**
• Has to do with practice
o The gender doesn’t play a role until they reach a certain age (approximately 9 and up then a change in SKILL development)
o The environment plays a role in learning new skills because it provides the different genders with the opportunities to practice
o Physical development and opportunities for practice moderate the differences
o The noticeable difference becomes greater as children reach 7+ years of - 30• Neural Control of Gait/Posture (what regions of nervous system?)• Parallel loop systems of motor control (cortex-cerebellum, cortex-basal ganglia)…general functions of each.
• Proximal to Distal rule of recruitment
o “proximal to distal”
o This falls under the progression of recruitment (size and encoding principles)
o The trunk is composed of small oxidative Type I muscles fibers which are recruited first because of their low thresholds and as more of them are recruited it leads to calling on the muscles from the limbs such as moving the arms (this happens almost instantaneously which is why we never notice it)
o If you cannot recruit the smaller muscles in charge of posture then it would become more difficult if not extremely strenuous to recruit other muscle like the ones more distally (limbs)
• Energy use: not energy efficient to the point where you are spending more energy maintaining the bad posture than using it for the other functions
• Joint load: the mix of balance problems and energy efficiency can cause a favoring of one type of leg or putting more stress on only certain parts of the joint body
• Balance: with the different postu - 31• Central nervous system changes in agingo Cortical atrophy
o Decreased cortical volume/gray matter reduced
o Decreased neurochemical flux (decreased neurotransmitters)
o Increased cortical effort (especially prefrontal)/neurochemical activation - 32• Paradox of Motor control in aging—apply to situations
- 33• Last In –First Out Hypothesiso Last regions to develop are the first to atrophy
o Your last to develop would be the higher cortices, so they would atrophy first - 34• How does sensorimotor integration change in aging? Does this have anything to do with receptor activation?o Sensorimotor integration:
• Parietal cortex atrophy
• Decr. white matter (myelin deterioration)
• Decr. proprioception (this specifically effects the receptor potentials/how well the receptors fire) **think of the older people and restaurant example**
• Cerebellar input is reduced (needs to have sensory input to fx so without it it will be reduced)
• Decr. MS sensitivity
o Yes with the decreased sensory input it will cause the receptor activation to decrease (since we are sensory driven beings it is highly effective when do not have all the information we need to cause the necessary changes) - 35• Know definitions of Neural de-differentiation and De-automatization of movemento De-automatization:
• Simple tasks become more cognitive (we need to think about it more) due to the attempt of greater recruitment of prefrontal regions
• There is going to be less feedback control from the closed loop systems
o De-differentiation:
• Non-selective recruitment of cortical regions to perform a motor task
• Cortical activation of additional brain regions (over-recruitment) for a given task
• May result from lack of inhibition
• Less neural precision
• Incr. variability of movement - 36• Apply Dual Task Cost to daily activitieso Most can easily multi-task (not overly cognitive)
• Text/listen
• Eating/talking
• Sports
o Physical with mental activation
• Used with assessing mental fx (good for testing improvements)
• Alzheimer’s and concussions
• Different areas of the brain are being challenged→making it increasingly cognitive
o Incr. utilization of cognitive + motor activity (older adults more demanding attention to the task)
o Incr. blood flow to normally silent areas during walking (areas like the prefrontal/supplemental motor areas, which is due to incr. activation) - 37• Muscle physiology changes in agingo You have an increased co-activation of agonist and antagonist (stiffness)
• Opposite of the half-center CPG model
o Incr. hip flexor activity (knee pathologies to decr. pain on knee)
• Decreased proprioception
• Extensor of back due to incr. vestibulospinal fx
o Decr. stride fine tuning (mainly due to decr. proprioception)
o Longer stance phase
o Motor neuron activation is wider and more variable (de-differentiation) 3-4 different patterns
o Sarcopenia/dynapenia
• S: loss of muscle tissue
• Altered activation of motor neurons specifically of large proximal muscles
o Older people can change strength neutrally
• Decr. motor unit size/# (losing Type II)
• Slower cross bridge
• 3-5% dynapenia/year after 70
• Loss of descending drive
• D: decrease in strength - 38Muscle physiology with age photo
- 39• Upper and lower motor neuron injury differenceso Upper: disease/dysfunction of pathway from motor cortex to AHC (not including, only the pathway); brain stem and up
• Strokes
• TBI
• SC injury (L4/5 up)
• Cerebral palsy
• MS→large myelinated neurons
• Characteristics:
• Spasticity (velocity dependent)/high tone
o No inhibition of lower centers
o Both will lead to atrophy for under usage
• Weakness
• Incr. reflexes (hyperreflexia)
• No fasiculations
• Myopathies: various muscular dystrophies of a genetic nature(dystrophin metabolism)
• Muscle tissue degeneration
• NOT neurogenic
• Weakness, cramping, paralysis (all in the proximal muscles)
o Lower: disease/dysfunction along path from the anterior horn cells of the spinal cord to the neuromuscular junction
• Neurogenic: injury to the nerve
• Spinal muscular atrophy
• AHC = polio, ALS
• Spinal radiculopathies (most common)
o Pinch nerves/compressed nerves
• Mononeuropathy (carpal tunnel)
• Characteristics: weakness (compression = decr. AP)
• Atrophy/wasting (flaccid paralysis)
o C5→atrophy in muscles (mostly in rural situations)
• Loss of reflexes: motor/sensory pat - 40• Disease of receptors:o Myasthenia Gravis → autoimmune → attacks ACh **facial weakness**
o Lambert-Eaton Syndrome → autoimmune → Ca++ - 41• Neurometabolic cascadeo There is immediate structural dysfunction → K+ (wants out)
o Neurological membrane injury (K+) leakage = spontaneous AP
o Incr. Glutamate (most common excitatory) ⇒ incr. CA++, decr. GABA (most common inhibitory)
o Glutamate attaches to NDMA (triggers) = potently excitotoxic
o Na/K pump needs energy (ATP) kicks into overdrive
• Decr. in Na and an Incr. in K in the membrane (blood flow is also decr. temporarily)
o Trained for 5k → marathon will not do so well
• Marathon for neurons when they cannot compete
• Incr. glycolysis = incr. lactate (this is a cause of the blood flow decr.)
o The glycolysis causes excess Ca++ inside the cells = apoptic/cell death
o This causes an increase in everything (go from dim → high) - 42• Symptoms of concussiono Hyperocussis
o Headache
o Dizziness/vestibular
o Balance
o Concentration
o Memory
o Nausea
o Light sensitivity
o Ringing
o Decr. rxn time
o Decr. focus
o Decr. verbability
o Blurred vision (tunnel/blindness)
o Confusion/disorientation
o **delayed concussion = fatigue** - 43• 3 consistent findings in people that have experienced concussionso Disorientation/confusion DAY OF
o Loss of balance W/IN ONE DAY
o Decr. rxn time W/IN 2 DAYS
o Verbal/memory dysfunction W/IN 2 DAY - 44Application of knowledge to movement or skill: Be able to explain the Neural Control of Movement “x”…Example: Explain, in as much detail as you can, the neural control of a performing a push-up. You should be able to discuss the various topics covered this semester including: neurophysiological (action potentials), neuroanatomical (structures), neuromuscular (motor unit activation and recruitment), hierarchy (cns/pns and control mechanisms), motor learning (developing skill), and motor control theories (regulation of the movement).
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