The control of action Flashcards
An important scientific breakthrough in the treatment of Parkinson’s disease from the tragic overdose of adults in San Jose, California, who thought they had taken heroin but instead had ingested MPTP, a chemical that selectively destroys
D……………………………… cells.
Dopaminergic
The discovery of the effect of
M………..
allowed for the creation of animal models of Parkinson’s disease, and, thus, the massive increase in studies of Parkinson’s disease treatment.
MPTP
A part of the body that can move is referred to as an
E…………………….
Effector
A…………..
motor neurons provide the primary communication between muscles and the nervous system.
Alpha
Alpha motor neurons originate in the
S……………. cord
and terminate on
the M…………………..,
releasing the neurotransmitter
A………………………………..
and causing muscle contraction.
Spinal
Muscles
Acetylcholine
Extrapyramidal tracts receive input from
C………………….. and S……………………..
structures and send information to
the S……………….cord.
The D……………………….. fibers
originate in the
B…………………………….
Cortical
Subcortical
Spinal
Descending
Brainstem
The corticospinal tract is also referred to as the
P……………………….. tract.
These descending fibers originate in the cortex and project
M………………………………..
to the spinal cord.
Pyramidal
Monosynaptically
Primary motor cortex (Brodmann area 4) is
A…………………. to the
C…………………. sulcus.
Most of the
C…………………….. F…………………………
originate in this area.
Anterior
Central
Corticospinal Fibers
Brodmann area …….
includes
S……………………….. motor areas
like the P……………………. cortex and the
S…………………………….. motor area.
6
Secondary
Premotor
Supplementary
The primary and secondary motor cortices contain
S……………………………
representations.
Somatotopic
Motor areas are
H……………………. :
The L……………………. level
is the S…………………… cord,
from which motor neurons project to activate muscles.
Hierarchical
Lowest
Spinal
Subcortical and cortical areas, including motor cortex, can represent actions at more
A…………………… levels
corresponding to movement
G……………………
Abstract
Goals
Although areas higher on the motor hierarchy
M……………………. activity,
L…………… levels
are sufficient for producing movement
P…………………….
Modulate
Lower
Patterns
The S………………… reflex
is an important spinal mechanism for maintaining postural stability. It remains presence in the absence of higher level commands.
Stretch
Descending motor signals
must M…………………
stretch reflexes to produce
V…………………………
movements.
Modulate
Voluntary
Motor plans represent
the G……………….
of motor actions. They can be location based as in
E………………………… control,
or they can be
R……………………………..
of distance or
T……………………………
plans for an action.
Goals
Endpoint
Representations
Trajectory
Motor learning can occur at a high level in the motor hierarchy,
I………………………………
of the muscular system (as demonstrated by your ability to sign your name fairly well with your dominant hand, nondominant hand,
T…………..,
or even mouth).
I…………………………………
T……………
A population vector is a representation of a movement formed by
S……………………………
of the activity of many neurons, usually in
P………………………. or S………………………..
motor cortex.
Summation
Primary
Secondary
Population vectors can be used to predict intended
M…………………………..
Movement
When hooked up to a
C…………………… or
R………………. A……………,
the population vector can be used to control a computer cursor or robotic arm.
Computer
Robotic Arm
Such brain-machine interfaces may prove useful for people who have
L…………
mobility because of stroke or another neurological problem.
Lost
M……………….. neurons
are neurons in premotor cortex
and other areas (like the parietal lobe) that respond to an action, both when the animal
O…………………. a S………………
action produced by another animal.
Mirror
Observes
Similar
A mirror neuron might
R……………………..
when the animal cracks a peanut, as well as when the animal
W………………….
someone else crack a peanut or
H……………….
the sound of a peanut cracking.
Respond
Watches
Hears
S……………………. motor neurons
tend to be active during
I………………………..
guided movements.
Supplementary
Internally
P………………….. neurons
tend to be active during
E……………………..
guided sequences.
Premotor
Externally
P………………….. circuits
are involved in motor planning.
Parallel
A circuit that includes the parietal lobe, lateral premotor and cerebellar pathways is essential for producing spatially
D……………….. or G…………………..
movements.
Directed
Guided
These movements dominate during the early stages of
S…………….. A…………………….
Skill
Acquisition
A second circuit, associated with the
S……………………….. motor area,
B……………….. G………………,
and perhaps
the T………………… lobe,
becomes more dominant as the skill is well learned and driven by an internal representation of the desired action.
Supplementary
Basal Ganglia
Temporal
Both circuits converge on
the M…………… C……………..,
the primary link between the cortex and limbs for
V………………… movements.
Motor Cortex
Voluntary
The cerebellum is located at the base of the
M………….. P………………………
portion of the brain.
Most
Posterior
The cerebellum is divided into three parts:
V……………………………,
S…………………………… and
N……………………………..
Vestibulocerebellum
Spinocerebellum
Neocerebellum
The vestibulocerebellum is innervated by the brainstem
V…………………….. N…………………….,
and output is projected back to the
S………………… region.
Vestibular Nuclei
Same
The output from the spinocerebellum originates in the
M……………….. cerebellar nuclei
and innervates
the S……………. cord and
N…………. of the
E………………………. system.
Medial
Spinal
Nuclei
Extrapyramidal
The neocerebellum is heavily innervated by the
C………………….. C…………………
and sends its output back to the cortex.
Cerebral Cortex
One computational account of cerebellar function emphasizes a role in controlling
the T……………. of M……………………..
A variant of this idea is that the cerebellum provides
P…………………………
of forthcoming sensory events.
Timing
Movements
Predictions
The basal ganglia are a collection of five nuclei:
the C…………………,
P…………………..,
G………………… P…………………..,
S…………………… nucleus,
and substantia N…………………
Caudate
Putamen
Globus Pallidus
Subthalamic
Nigra
I……………….. to
the basal ganglia is restricted primarily to the caudate and putamen, collectively called the
S……………………
Input
Striatum
O…………….. from
the basal ganglia originates in the
I…………………… segment
of the globus pallidus and part of the substantia nigra.
Output
Internal
Motor control by the basal ganglia is cortically mediated via
T…………………… projections.
Thalamic
There are two pathways within the basal ganglia:
D…………………. and I……………………..
Direct
Indirect
The direct pathway consists of direct inhibitory projections from
the S………………….. to the
G………………….. P…………………
and S………………….. N…………………..
Striatum
Globus Pallidus
Substantia Nigra
The indirect pathway also connects the striatum to these output nuclei, but only through intervening processing stages involving
the E…………….. segment of the
G………………… P…………………
and the S……………………. nucleus.
External
Globus Pallidus
Subthalamic
All the output signals from the basal ganglia are
I……………………..
Inhibitory
The basal ganglia can be hypothesized as playing a critical role in the
I………………….. of actions,
or the ability to shift actions to those that are most often
R………………………
Initation
Rewarded
Hemiplegia most frequently results from hemorrhage in
the M………………. C…………………… A………………….
and results in a
L……………… of voluntary movements
on the side of the body
C…………………………..
to the lesion.
Middle Cerebral Artery
Loss
Contralateral
A…………………..
is characterized by coordination deficits that cannot be attributed to hemiplegia, motoric problems of weakness, sensory loss, or motivation.
Apraxia
In I…………………… apraxia,
a patient appears to have a sense of what the desired action is but cannot execute the action properly.
Ideomotor
In I……………………….. apraxia,
the patient’s knowledge about the intent of an action is
D………………………..
This deficit often manifests itself in the lost of
K………………………..
of proper tool use.
Ideational
Disrupted
Knowledge
Apraxia is usually associated with
L…..-H…………….. lesions,
often in the
P…………………….. C……………….
Left-Hemisphere
Parietal Cortex
Damage to the cerebellum produces
A………………….
in which movements become
U………………………. and E……………………..
Ataxia
Uncoordinated
Erratic
Parkinson’s disease results from
cell death D………….
in the S……………………. N…………..,
a brainstem nucleus that is part of the basal ganglia.
Death
Substantia Nigra
Parkinson’s disease includes disorders of
P………………….. and L……………………,
H………………………….
(the absence or reduction of voluntary movement), and
B……………………………
(slowness in initiating and executing movement).
Posture
Locomotion
Hypokinesia
Bradykinesia
The drug
L-D………….
is used in treating Parkinson’s disease because it is effective in compensating for the loss of
E………………………… D…………………………..
Dopa
Endogenous
Dopamine
D………-B…………. stimulation
is a surgical technique in which electrodes are chronically implanted in the brain.
This procedure has become a novel treatment for Parkinson’s disease with implants usually placed in the
S………………………….. nucleus.
Deep-Brain
Subthalamic
Huntington’s disease is a
P………………….. D……………………….
disorder that appears in the fourth or fifth decade of life.
Progressive
Degenerative
Huntington’s disease is is characterized by
C…………………….,
B………………….. problems,
R…………………………
and I……………………….. movements (or chorea).
Clumsiness
Balance
Restlessness
Involuntary
A………………….
is most prominent in the basal ganglia, especially the striatum. Huntington’s disease has a
S……………….. G……………………
component.
Atrophy
Strong
Genetic
