Module 7 - Motor and Sensory Systems Flashcards
What do the premotor and supplementary motor areas do?
receive info from broca’s area and association areas of parietal lobe and pass info to primary motor cortex
What does the premotor area get info about?
external cues; info about environment, where you are in space
What does the supplementary motor area get info about?
internal cues - motor programs that are learned
What are the functions of the basal ganglia?
regulate muscle tone, regulate ongoing movements, inhibit extraneous motor activity, motor learning
Where does the basal ganglia get info from and where does that info go?
BG gets info from everywhere, sends it everywhere
What is the neurophysiological consequence of damage to the basal ganglia?
loss of inhibitory control over motor behaviors
What are some symptoms of damage to the BG?
dyskinesia - involuntary movement bradykinesia - slow movement hypokinesia - limited range of movement postural abnormalities altered muscle tone
What are the types of dyskinesia?
athetosis - slow involuntary writing movements
ballism - violent, forceful flinging movements
chorea - involuntary, rhythmic movements
tremor - resting, action, postural, intention
What are some diseases associated with the BG?
parkinsons, huntington’s, wilson’s (degeneration in basal ganglia, hereditary)
What is parkinson’s?
destruction of dopamine producing cells
What are the functions of the cerebellum?
muscle synergy, muscle tone, range of movement, strength of movement, equilibrium
How does the cerebellum connect to the brainstem?
peduncles - superior (e), middle (a), inferior (a)
The cerebellum receives extensive sensory input, but…
it is not involved in sensory discrimination or interpretation
The cerebellum influences motor function, but…
when lesioned does not result in paralysis
The cerebellum is involved in motor learning by…
modifying motor activity based on results of movement
The cerebellum knows intention and results and so…
makes adjustments based on results
The cerebellum receives info from
motor cortex
spinal cord
brainstem
The cerebellum sends info to
thalamus, brainstem (red nucleus)
Damage to the cerebrocerebellum results in what?
tremors
Damage to the spinocerebellum results in what?
hypotonia, hypertonia
Damage to the vestibulocerebellum results in what?
balance and gait problems
What are some symptoms resulting from cerebellar damage?
ataxia, tremor, dysdiadochokinesia, dysmetria, rebound, disequilibrium
What is ataxia?
discoordinated muscle activity (can be genetic or acquired)
What kinds of tremors can be caused by cerebellar damage?
action, terminal (gets worse as limb approaches target), postural
What is dysdiadochokinesia?
awkward performance of rapid alternating movements (pataka), disruption of rhythmic movements
What is dysmetria?
impairment in judging distance to target (over or undershoot when reaching for something)
what is rebound?
inability of agonist and antagonist to adapt to rapid changes in load
What is disequilibrium?
unsteady, lurching gait, appearing drunk, exaggerated movements of legs (trying to overcompensate), tendency to fall
What is a motor unit?
LMN + group of muscle fiber
What are the three things muscles can do?
contract, relax, stretch
What are the kinds of proprioceptors?
stretch receptors (spindles within each muscle - intrafusal fibers) tension receptors - golgi tendon organs, within tendons joint receptors
what are extrafusal fibers?
contractile elements, under direction control of LMN (alpha motor neuron)
What are intrafusal fibers?
muscle spindles, under control of gamma motor neuron?, have proprioreceptors – feedback
influenced by cerebellum, basal ganglia, and extrapyramidal system
What is the importance of gamma loops?
they give us muscle tone; allow us to sit up and stuff.
What are the muscle conditions we learned about?
paresis, paralysis, fasciculation, fibrillations
What is paresis?
some alpha motor neurons are damaged
What is paralysis
all motor neurons damaged
What is fasciculation?
rippling muscles, spontaneous discharge
What are the types of pyramidal pathways?
corticobulbar (corticonuclear), corticospinal
What are first order sensory neurons?
innervate sense organ in PNS; ipsilateral
What are second order sensory neurons?
projection neurons located in brain stem or spinal cord, point of deccusation, go to thalamus
What are third order sensory neuron ?
cerebral cortex, primary sensory cortex
What are the transducers for the somasthetic system?
tactile system receptors (non-discriminative and discriminative touch)
free nerve endings (pain, cold, heat)
proprioception and
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