Motor Control Flashcards
Chorea
An abnormal involuntary movement disorder
Movements
simple reflexes with brief muscle activation
eyeblink, hiccup, finger twitch
Acts/action patterns
Complex, sequential movements
honking your car horn, writing your name, playing lead guitar
Motor plan/motor program
a set of muscle commands established before the action occurs
Most of the brain’s activity is ultimately _____.
motoric
preparing to move, moving, correcting movement
Open-loop control
maximizes speed
Ballistic movements
rapid, completed no matter what sensory feedback is received
Closed-loop control
maximizes accuracy
information from what is being controlled flows back to the controlling device
Ramp movements
smooth movements
slower, sustained motions guided by feedback
Skeletal system and muscles power _____.
movement
Spinal cord controls _____.
skeletal muscles
The brainstem integrates _____.
motor commands
Primary motor cortex initiates _____.
commands for action
Nonprimary motor cortex initiates _____.
cortical processing
_____ tweak the brainstem, primary and nonprimary motor cortex.
Cerebellum and basal ganglia
Muscles that contract when others extend are _____.
antagonists
Muscles that act together are _____.
synergists
At rest, flexor and extensor muscles are ____.
balanced
A tremor is _____.
an alternation of flexor-extensor contraction
A muscle is composed of _____.
muscle fibers
muscle fibers contain two kinds of regularly arranged, overlapping filaments: _____ and _____ filaments.
thick (myosin)
thin (actin)
Striated muscles - voluntary – contain two types of fibers:
_____ and _____ muscle fibers
fast-twitch
slow-twitch
Slow-twitch fibers _____, _____, and _____.
contract slowly
resist fatigue
are the first to be recruited
Fast-twitch fibers _____, _____, and _____.
contract rapidly
fatigue easily
are the last to be recruited
Motoneurons send their axons to _____.
innervate muscles
Action potentials travel down the _____, which branches into many _____ near its target
motoneuron
terminals
The neuromuscular junction is where _____ and _____. meet
motor neuron terminal
muscle fiber
___ is released at the neuromuscular junction.
Acetylcholine (ACh)
A motor unit is a motoneuron’s _____ and all of its _____.
axon
target fibers
The Innervation ratio is the _____.
number of fibers innervated by an axon
fibers/axon
Muscles that make fine, precise movements have only _____.
a few muscle fibers per axon
Action of muscles are guided by _____.
sensory feedback
Proprioception is the collection of information about _____ and _____.
body movements
position
Muscle spindles are responsive to _____.
muscle stretch
Golgi tendon organs responsive to _____.
muscle contraction
less to stretch
If a muscle is stretched, the muscle _____ to maintain its ‘preset’ length.
contracts
Stimulation of Golgi tendon organs inhibits _____, thereby relaxing _____ and preventing _____.
motoneurons
extreme tension
damage
When normal cortex input is cut off, the spinal cord becomes _____.
hyperreflexic
Hyperreflexic
normal reflexes are exaggerated
Clonus
muscular spasm involving repeated, often rhythmic contractions
Pyramidal
muscles of the body
Extrapyramidal
muscles of the head and neck
The Pyramidal System Pathway is a _____.
two neuron chain
The Pyramidal System Pathway involves neuron 1 from _____ to _____ in the medulla, where it crosses over, then down the _____ to end at the _____.
primary motor cortex
pyramid
spinal cord
anterior horn cell (motoneuron)
The Pyramidal System Pathway involves neuron 2 from _____ to _____.
motoneuron
muscle
Primary motor cortex changes as a result of _____.
learning
Early music training results in _____.
expansion of motor cortex
Nonprimary motor cortex is just anterior to __.
M1
The supplementary motor area (SMA) encodes _____.
sequences of movements
In the premotor cortex, neurons fire _____.
just before performing an activity
Mirror neurons in _____ fire when observing _____.
premotor cortex
another doing that task.
The _____ is located in the basal ganglia.
extrapyramidal system
The cerebellum cortex contains _____ cells, which only send _____.
Purkinje
inhibitory messages
The cerebellum guides movement through _____.
inhibition
The _____ and _____ modulate movements
cerebellum
basal ganglia
The _____ and _____ are more involved in early phase of a movement than the _____ and the _____.
primary motor cortex
basal ganglia
SMA
cerebellum
Voluntary movements have _____ consequences.
postural
The _____ predicts postural consequences of planned movement and acts to _____.
extrapyramidal system
prevent loss of balance
Rhythmic activities, such as walking, are generated in the _____.
spinal cord
Strength is largely a(n) _____.
power
pyramidal function
Tone is largely a(n) _____.
posture
extrapyramidal function
Pyramidal damage causes _____.
weakness
Extrapyramidal damage causes _____.
impaired movement control
Myopathy is a disease of _____, causing _____.
muscle fibers
muscular weakness
Muscular dystrophy is the disorder of _____, caused by abnormal or no _____ production.
progressive degeneration of muscle
dystrophin
_____ is a protein needed for normal muscle function and is produced by _____.
Dystrophin
X chromosome
Myasthenia gravis is a(n) _____ in which patients develop antibodies to own _____.
autoimmune disorder
ACh receptors
(Weakness of skeletal muscles that develops over the day, resolves with rest/sleep)
Poliovirus destroys _____ and sometimes _____.
spinal motoneurons
cranial motoneurons
Amyotrophic lateral sclerosis (ALS) or Lou Gehrig’s disease is caused by _____ and results in _____.
the degeneration of motoneurons
consequent loss of their target muscles
Spina bifida is a result of _____ deficiency in the mother during pregancy.
folic acid
Spinal cord injuries result in _____.
_____, _____, and _____ below level of the injury are lost.
flaccid paralysis
Reflexes, sensation, strength
Apraxia results in _____.
the inability to sequence movements
although no muscle paralysis exists
New movements are _____.
ramped and feedback-controlled
slow, variable
Well-learned movements are _____.
ballistic
fast, consistent
Parkinson’s disease is a result of a defective gene for _____ is a(n) _____ cause of Parkinson’s.
Degeneration of _____ cells in the _____, which project to the basal ganglia also cause Parkinson’s disease.
α-synuclein (a basal ganglia protein) inherited dopamine substantia nigra (can be treated with L-dopa)
Common symptoms of Parkinson’s disease include _____, _____, _____, and _____.
tremors, bradykinesia, shuffling gait, and postural instability
Chorea is a neurological disorder resulting in _____ and appear to _____.
irregular movements that are not repetitive or rhythmic
flow from one muscle to the next
(dancing arms and hands)
Huntington’s chorea is caused by _____ and
It results in progressive destruction of the _____ and _____, as well as impairment of the .
repitition of the trinucleotide repeat gene (CAG), which is variable in length
(If it repeats too many times the disease develops)
caudate nucleus
putamen
Cerebral cortex
Ataxia is a result of _____.
Cerebellar damage
impairs motor control
_____ causes gait ataxia.
Alcoholism
Purkinje cells die
Dystonia results in _____, _____, and _____.
sustained, patterned muscle contractions
abnormal sustained posture
basal ganglia dysfunction
Tourette syndrome is a combination of _____ and _____, resulting from _____ and _____ disorder.
Tics
OCD
Basal ganglia
cortex
Hemiparetic gait is caused by _____, resulting in _____.
motor cortex damage (such as stroke)
motor impairment
(Weakness (paresis) of voluntary movements)
