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68 Cards in this Set
- Front
- Back
What are the three behavioral viewpoints when considering motor movements?
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reflexes
motor plans acts |
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What are motor plans?
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Acts that are a series of predetermined movements.
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What are movement acts?
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Goal-directed series of motor actions
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What are the two control system types when we consider movement?
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Closed loop control (sometimes called ramp movements)
Open loop control (sometimes called ballistic) |
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What are the levels of organization in the neurobioligical point of view?
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-skeletal system sets limits on possible motion
-spinal cord controls and implements brain commands -brainstem integrates and relays -commands initiated in primary motor cortex -non-primary (or supplemental) motor cortex initiate other levels of programming -cerebellum and basal ganglia modulate activities of other systems |
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What types of joints are there?
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Hinge
Ball-and-socket Ellipsoidal |
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What connects muscles to bone?
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Tendons
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What are the two ways muscles work together?
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Antagonistically (biceps and triceps)
Synergistically |
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What two filaments make up muscle fiber?
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myosin
actin |
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What does contraction of muscles do to the muscle fibers?
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It increases their overlap
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What are the two different types of muscles?
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smooth
striated |
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What are the two different types of striated muscles?
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slow-twitch
fast-twitch |
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What are the characteristics of slow-twitch muscles?
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act slower but resist fatigue
used for posture are large diameter |
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What are the characteristics of fast-twitch muscles?
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respond quickly but fatigue quickly
used for rapid movement are small diameter |
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How many muscle fibers does an average motorneuron innervate?
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many
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How many axon collaterals per muscle fiber?
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1
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What neurotransmitter do neuromuscular junctions use?
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Ach
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How often does a motorneuron firing create an action potential?
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Nearly every time.
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What is posttetanic potententiation?
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The increased responsiveness of a NMJ to additional action potentials after experiencing a string of rapid action potentials.
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What ratio of fibers to axons is required for fine motor movements?
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Roughly 1:3
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What ratio of fibers to axons is required for gross motor movements?
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Roughly 1:300
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What is the size principle?
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The orderly recruitment of motor units. It is similar to range fractionation.
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What are muscle spindles?
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A muscle structure containing afferent and efferent elements.
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Where do primary sensory endings terminate in a muscle spindle?
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on small intrafusal fibers within the spindle
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Where do secondary sensory endings terminate in a muscle spindle
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secondary sensory endings (flower spray endings) terminate near thin ends of spindle.
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Describe primary spindle endings.
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primary endings react fast, then adapt to a lower level—dynamic indicators.
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Describe secondary spindle endings
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secondary endings react slowly in early phase and are most sensitive to maintained stretch—static indicators
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What are gamma efferents?
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Gamma efferents connect to myotube region and change length and tension of spindle to modify sensitivity to changes in length of extrafusal fibers
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What are Golgi tendon organs?
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Golgi tendon organs respond to contraction, detect overloads
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Give examples of automatic motor responses.
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flexion reflex, bladder emptying.
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What is the stretch reflex?
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weight added to hand triggers response from muscle spindle, which connects monosynaptically to motoneuron, which stimulates return to original position
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What is the pathway from the brain that controls motor movements?
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pyramdial tract:
frontal cortex-->cross at medulla-->descend lateral tract |
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What is another name for the primary motor cortex?
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Precentral gyrus.
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Where is M1 located?
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anterior to the central sulcus
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What is the executive system for voluntary movement?
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motor-cortex pyramid.
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Does M1 represent muscles, movements, or both?
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Both, but muscles to a lesser extent.
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What parts make up the nonprimary motor cortex?
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Supplementary motor area and the premotor cortex
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What is the non-primary motor cortex for?
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Skilled movement
conception and initiation of movement |
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What is the SMA activated by?
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complexity and mental rehersal
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What is the premotor cortes activated by?
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external guidance stimuli
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What are the parts of the extrapyramidial system?
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basal ganglia (putamin, globus pallidus, caudate)
red nucleus reticular formation |
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What does the cerebellum do?
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Receives feedback from all motor monitoring and executing systems
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What is Muscular dystrophy?
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muscles waste away due to biochemical abnormalities—abnormal dystrophin protein
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What is Myasthenia gravis caused by?
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antibodies destroying postsynaptic Ach receptors at neuromuscular junction
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What is amyotrophic lateral sclerosis caused by?
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genetic cases (10%) appear to involve an enzyme that normally coverts free radicals to less reactive compounds; high levels of glutamate may also be involved
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What can spinal cord damage cause?
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cause flaccid paralysis (if large stretch damaged) or excessive reflexes when brain inhibition is gone
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What can strokes cause?
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paresis paralysis or spasticity; in association or SMA, can cause ideomotor apraxia (cannot do simple act to verbal command) or ideational apraxia
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What is Parkinson's Disease?
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degeneration of A-containing cells in substantia nigra, which project to striatum; L-dopa works for a while, recently have tried implants of fetal brainstem cells with mixed results.
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What is Huntington's Disease?
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progressive destruction of basal ganglia and impairment of cortex by defective huntingtin; triggered when CAG repeats reach 38 or more.
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What can Cerebellar damage cause?
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ataxia or decomposition of movements; may be due to disruption of comparison of ongoing act with in-register maps
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What do diurnal and noturnal refer to?
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Diurnal = active during the day
Nocturnal = active during hte night. |
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What is the master clock of the body
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The suprachiasmatic nucleus (SCN) in the hypothalamus
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What photopigment is used to communicate to the SCN?
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melanopsin
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What are other internal clocks?
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infraradian
ultraradian circannual |
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Do humans free run?
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Yes
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What is frequency of stage 1 sleep
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9-12 Hz
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What is the frequency of stage 2 sleep?
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12-14 Hz
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What kind of waves in stage 1 sleep
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Alpha
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Stage 3 & 4 have what kind of waves?
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Delta
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What does REM sleep most closely resemble
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Stage 1 or waking?
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Normal pattern of REM sleep during the night?
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More at the end than the beginning.
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What are the different kind of dreams Non versus REM sleep
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REM = visual
Stage 2 = thinking |
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What is difference between night terrors and nightmares
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Night terrors = stage 3 & 4
nightmares = rem sleep |
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What neurotransmitter makes nightmares more frequent
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dopamine
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Does REM sleep increase or decrease with age?
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decrease unless learning
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What stage of sleep is recouped the most after sleep deprivation?
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REM
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What are the four biological theories of sleep?
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Energy conservation
Avoiding predation Body restoration—suprisingly little research support for this Consolidation of certain kinds of learning |
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Brain structures involved in sleep?
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Basal forebrain involved in initiation of slow-wave sleep
Reticular system in pons and medulla initiates waking BP 14.21 --this system is involved in other forms of activation and alertness, as well as experience of pleasure Raphe nucleus, which uses serotonin, seems to be involved in initiating sleep BP 14.22 Locus coeruleus in pons involved in producing muscle atonia Hypocretin neurons in hypothalamus project to all sleep centers and appear to be the switch from waking to SWS to REM |