Motor Flashcards
1
Q
Simple reflexes with brief muscle activation
Ex: eyeblink, hiccup, finger twitch
A
Movements
2
Q
Complex sequential movements
Ex: honking your car horn, writing your name, playing lead guitar
A
Acts (action patterns)
3
Q
A set of muscle commands established before the action occurs
A
Motor plan (motor program)
4
Q
- most of the brain’s activity
- preparing to move, moving, correcting ongoing movement
A
Motoric
5
Q
The only reason we need a brain at all is
A
To move
6
Q
The whole point of our brain is to
A
Guide movement
7
Q
- open-loop control
- ballistic movements
A
Two control mechanisms optimize accuracy and speed
8
Q
- maximizes speed
- no guiding external feedback
A
Open-loop control
9
Q
- rapid
- completed no matter what sensory feedback is received
A
Ballistic movements
10
Q
- closed-loop control
- ramp movements
A
Two control mechanisms optimize accuracy and speed
11
Q
- maximizes accuracy
- information from what is being controlled flows back to the controlling device
A
Closed-loop control
12
Q
- smooth movements
- slower, sustained motions guided by feedback
A
Ramp movements
13
Q
-skeletal system and muscles
-spinal cord
-brain stem
-primary motor cortex
-nonprimary motor cortex
-cerebellum and basal ganglia
A
Hierarchy of motor control systems
14
Q
Power movement
A
Skeletal system and muscles
15
Q
Control skeletal muscles
A
Spinal cord
16
Q
Integrates motor commands
A
Brainstem
17
Q
Initiates commands for action
A
Primary motor cortex
18
Q
Initiates cortical processing
A
Nonprimary motor cortex
19
Q
Tweak these systems
A
Cerebellum and basal ganglia
20
Q
-planning
-initiating
-directing voluntary movements
-descending systems (upper motor neurons)
A
Motor cortex
21
Q
-basic movements
-posture control
-descending systems (upper motor neurons)
A
Brainstem centers
22
Q
-reflex coordination
-spinal and brainstem circuits
A
Local circuit neurons
23
Q
-lower motor neurons
-spinal cord and brainstem circuits
A
Motor neuron pools
24
Q
Gating proper initiation of movement
A
Basal ganglia
25
Sensory motor coordination
Cerebellum
26
Muscles that contract when others extended are
Antagonists
27
Muscles that act together are
Synergists
28
Flexor and extensor muscles are balanced
At rest
29
-alternation of flexor-extensor contraction
-normally present, but if poorly regulated it is debilitating
Tremor
30
Biceps and triceps are
Antagonists
31
-a muscle is composed of
-each contain two kinds of regularly arranged, overlapping filaments
Muscle fibers
32
Thick filaments
Myosin
33
Thin filaments
Actin
34
Shortens the fiber length
Contraction
35
Voluntary
Striated muscles
36
-fast twitch muscle fibers
-slow twitch muscle fibers
Two types of fibers
37
-contract slowly but resist fatigue
-first to be recruited
-use fat for fuel
Slow twitch fibers
38
-contract rapidly but fatigue easily
-last to be recruited
-use glucose
Fast twitch fibers
39
Send their axons to innervate muscles
Motorneurons
40
Travel down the motorneuron, which branches into many terminals near its target
Action potentials
41
-motor neuron terminal and muscle fiber meet
-acetylcholine is released
Neuromuscular junction
42
One motorneuron’s axon and all its target fibers
Motor unit
43
Muscles that make fine, precise movements have only a few
Muscle fibers per axon
44
1/13
Innervation ratio
45
Is guided by sensory feedback
Action of muscles
46
Information about body movements and position
Ex: how tiger knows when to start his downswing
Proprioception
47
-muscle spindles
-gogli tendon organs
two kinds of muscle proprioceptive receptors
48
responsive to muscle stretch
muscle spindles
49
respond to muscle contraction, less to stretch
togli tendon organs
50
Are like the lad who is too little to play football, so he serves as team statistician
Muscle spindles
51
If a muscle is stretched, ______ ______ also stretches
muscle spindle
52
Afferent nerve impulses tell ______ ______ of the stretch
spinal cord
53
Muscle contracts to maintain '_____' length
present
54
Stimulation of ______ _____ _______ inhibits motorneurons, thereby relaxing extreme tension to prevent damage
Golgi tendon organs
55
1. Muscle is stretched
2. Excitation of muscle spindle afferents
3. Excitation of motoneurons
4. Agonist muscle stimulated to oppose stretch
5. Antagonist muscle is inhibited
Stretch Reflex Circuit
56
Muscle is stretched
Stretch reflex circuit #1
57
Excitation of muscle spindle afferents
Stretch reflex circuit #2
58
Excitation of motoneurons
Stretch reflex circuit #3
59
Agonist muscle stimulated to oppose stretch
Stretch reflex circuit #4
60
Antagonist muscle is inhibited
Stretch reflex circuit #5
61
Touching back of the hand resets the muscle spindles, for a few secs
Arm wrestling hack
62
Impaired control of the stretch reflex
Spasticity
63
-normally keeps a tight rein (inhibition) on reflex behavior
-reflexes don't interfere with voluntary movements
Motor cortex
64
When normal cortex input is cut off, spinal cord becomes
hyperreflexic
65
normal reflexes are exaggerated as in
clonus
66
Muscles of the body
Pyramidal
67
Muscles of head and neck
Extrapyramidal
68
- direct control
- Primary motor cortex
- non primary motor cortex
- spinal cord
Pyramidal
69
- indirect control
- basal ganglia
- thalamus
- cerebellum
Extrapyramidal
70
A two-neuron chain
Pyramidal system pathway
71
Upper Motor neuron
neuron #1
72
lower motor neuron
neuron #2
73
The cross over of the primary motor cortex and the pyramid in the medulla
Upper motor neuron
74
From spinal cord to muscle
Lower motor neuron
75
changes as a result of learning
primary motor cortex
76
early music training results in expansion of
motor cortex
77
plans movement
nonprimary motor cortex
78
- M1
- Primary motor cortex
Motor cortex
79
-SMA
-encodes sequences of movements during skill acquisition
Supplementary motor area
80
neurons fire just before performing an activity
Premotor cortex
81
guides movement through inhibition
Cerebellum
82
contains Purkinje cells which only send inhibitory messages
Cerebellum cortex
83
modulate movement
cerebellum and basal ganglia
84
are more involved in early phase of a movement than SMA and cerebellum
Primary motor cortex and basal ganglia
85
need postural adjustment
voluntary movements
86
- predicts postural consequences of planned (pyramidal) movement
- acts to prevent loss of balance
Extrapyramidal system
87
neutral circuit that generates rhythmic behaviors
central pattern behavior
88
rhythmic activities, such as walking, are generated in the
spinal cord
89
a very long journey
input to output
90
- power
- largely a pyramidal function
strength
91
- posture
- largely an extrapyramidal function
tone
92
causes weakness
pyramidal damage
93
impairs movement control
extrapyramidal damage
94
primary disorder of muscle
myopathy
95
progressive degeneration of muscle
muscular dystrophy
96
- a protein needed for normal muscle function
- produced by X chromosome
Dystrophin
97
- an autoimmune disorder
- patient develops antibodies to their own acetylcholine (ACh) receptors
- weakness develops over the day and resolves with sleep
Myasthenia gravis
98
Tension (acetylcholine agonist) test
Myasthenia gravis diagnosis
99
- destroys spinal motoneurons and sometimes cranial motoneurons
- no treatment
- spinal cord with loss of motoneurons
Poliovirus (polio)
100
- Lou Gehrig disease
- degeneration of motoneurons and consequent loss of their target muscles
Amyotrophic lateral sclerosis (ALS)
101
- result in paralysis
- reflexes, sensation, and strength below level of the injury are lost
spinal cord injuries
102
- inability to sequence movements
- no muscle paralysis exists
Apraxia
103
motor planning disorder
Sequencing
104
- new acts are ramped (feedback-controlled)
-slow, variable
Frontal and parietal cortex
105
- well-learned acts are ballistic
- fast, consistent
Cortex and basal ganglia
106
- tremor
- bradykinesia
- shuffling gait
- postural instability
Parkinson's disease
107
a basal ganglia protein
a-synuclein
108
- a defective gene for a-synuclein
-an inherited cause of
- environmental exposures also contribute
Parkinson's disease
109
degeneration of dopamine cells in _________ ______, which project to basal ganglia
substantia nigra
110
- a precursor to dopamine
- use as a drug improves the symptoms
L-dopa
111
dancing hands and feet
chorea
112
- progressive destruction of the caudate nucleus and putamen
- cerebral cortex also is impaired
Huntington chorea
113
- impairs motor control
-Purkinje cells die
cerebellar damage (ataxia)
114
childhood tumors of
cerebellar vermis (ataxia)
115
alcoholism causes
gait ataxia (ataxia)
116
inherited degeneration of
cerebellum (ataxia)
117
- abnormal sustained posture
- basal ganglia dysfunction
dystonia (severe)
118
tics and obsessive-compulsive disorder
Tourette syndrome
119
basal ganglia and cortex disorder
Tourette syndrome
120
- boys more than girls
- usually end by adulthood
- affect face and shoulders more than hands and legs
- coprolalia (swearing) is rare in children
clinical features of Tourette syndrome
121
- motor cortex damage, such as stroke, causes motor impairment
- weakness (paresis) of voluntary movements
Hemiparetic gait
