Motor Systems - Chp. 5 Flashcards
(57 cards)
Motor Programs?
The plan to produce a particular motor action, such as writing your name, that occurs independently of the effectors used to carry out the movement.
Lower Motor Neurons?
Also called primary motor neurons, are neurons that directly innervate muscles.
Local Circuit Neurons?
Also called interneurons, are neurons whose local connections contribute to processing circuitry.
Upper Motor Neurons?
Neurons that give rise to a descending projection that controls the activity of lower motor neurons in the brainstem and spinal cord.
Primary Motor Cortex?
A major source of descending projections to motor neurons in the spinal cord and cranial nerve nuclei; located in the precentral gyrus and essential for the voluntary control of movement.
Premotor Cortical Areas?
Cortical areas, including the premotor cortex, supplementary motor cortex, and parts of the parietal cortex, that provide motor programming signals to the primary motor cortex.
Premotor Cortex?
Part of the prefrontal cortex lying just anterior to the primary motor cortex; involved in planning movement.
Medullary Pyramids?
Longitudinal bulges on the ventral aspect of the medulla that signify the corticospinal tracts at this level of the nervous system.
Frontal Eye Fields?
A region of the prefrontal cortex in human and non-human primates, often associated with area 8a, that plays a key role in voluntary visual orienting movements.
Superior Colliculi (singular super colliculus)
Paired structures that form part of the roof of the midbrain; important in orienting movements of the head and eyes.
Saccades?
A ballistic eye movement that changes the point of binocular visual fixation; normally occur at a rate of about three to four per second.
Readiness Potential?
An electrical potential, recorded from the motor and premotor cortices with EEG electrodes, that signals the intention to initiate a voluntary movement well in advance of actual production of the movement.
Anosognosia?
Lack of awareness’s of one’s own disability.
Reward Value?
The likelihood that a particular movement will yield a reward, multiple by the amount of reward expected.
Supplementary Motor Area (SMA)?
Also called supplementary motor cortex, a premotor area, lying anterior to the primary motor cortex on the medial surface of the cerebral hemisphere, that plays an important role in movement planning.
The cerebellum & basal ganglia do not project to lower motor neurons; they work together to modulate motor activity via cortical connections.
Cerebellum = fine tuning movement.
Basal Ganglia = gating voluntary movement.
Optic Ataxia?
A neurological condition associated with damage to the dorsal parietal cortex, and is characterized by deficits in visually guided reaching.
Basal Ganglia?
A group of nuclei lying deep in the subcortical white matter of the frontal loves that organize motor behavior. The caudate, putamen, & globus pallidus are major components; the subthalamic nucleus & substantia nigra are often included.
Gating?
Allowing or permitting. The basal ganglia, for example, gate movement initiation. Channels through the neuronal membrane are often gated, allowing the access of certain ions under certain conditions.
Caudate?
One of the three major nuclei that make up the basal ganglia in the cerebral hemispheres. Together with the putamen, it serves as the input structure for the globus pallidus. Damage to this nucleus leads to hyperkinetic movement disorders, such as Huntington’s disease.
Putamen (Striatum)?
One of the three major nuclei that make up the basal ganglia.
Globus Pallidus?
One of the three major nuclei that make up the basal ganglia in the cerebral hemispheres. It relays information from the caudate & putamen to the thalamus.
Substantia Nigra Pars Reticulata?
A component of the midbrain substantia nigra nucleus that plays a key role in the suppression and initiation of saccadic eye movements.
Parkinson’s Disease?
A neurodegenerative disorder affecting the substantia nigra that results in a characteristic tremor at rest and a general paucity of movement.
Huntington’s Disease?
A autosomal dominant genetic disorder in which a single gene mutation results in damage to the basal ganglia that causes personality changes, progressive loss of the control of voluntary movements, and eventually death.
