motor systems Flashcards
functions of upper motor neurones
initiate, regulate, modify and terminate lower motor neurones
required for voluntary movement of skeletal muscle
where to UMNS to LMS supplying the extensor muscles travel
in the lateral funiculi of the spinal cord
where do UMNS to LMNS supplying extensor muscles travel
ventral funiculi of spinal cord
where are UMNS found
wholly within CNS
where are LMNS found
cell body in CNS and axon in the PNS
run via spinal or cranial nerves to innervate skeletal muscle fibres
what does an action potential in LMN cause
muscle contraction
components of motor unit
LMJ NMJ and skeletal muscle fibres
what do extensor muscles maintain
posture against gravity
what are extensor muscles tempered by and what does it lead to without
the effect of the inhibitory UMNs on the LMNs which supply the muscles
without inhibition extensors would take over leading to spacticity
effects of UMN injury
exaggerated reflex
effect of LMN injury
reduced or absent reflexes
difference between reflex and response
reflex is innate
response is learned
what does Y-1a-alpha lead to
amplification of signal
function of corticospinal tract
fine motor skills
function of rubrospinal tract
skilled movments
function of tectospinal tract
orientates head and eyes in response to sight and sounds
