lecture 10: motor systems Flashcards
true or false: motor pathways are usually 3 neurons
false, 2
where are the upper motor neuron cell bodies located
in cortex (or brainstem)
where are the lower motor neuron cell bodies located
in ventral horn or brainstem
UMN are CNS or PNS
CNS
LMN are CNS or PNS
PNS
upper motor neuron axons comprise tracts or nerves
tracts (central nervous system)
lower motor neuron axons comprise tracts or nerves
nerves (peripheral n system)
LMN innervate what
muscles
the motor pathways are broadly divided in what 2 systems
1) lateral motor system
2) medial motor system
the lateral motor system contains what info
control of appendicular muscles
control of appendicular muscles is laterlal or medial system
lateral
the medial motor system controls what
control of axial muscles (eg: postural tone)
control of axial muscles (eg: postural tone) is lateral or medial motor system
medial
what are the 3 divisions of the lateral motor system
lateral corticospinal
lateral reticulospinal
rubrospinal
what are the 4 divisions of the medial motor system
medial reticulospinal
anterior corticospinal
vestibulospinal
tectospinal
what pathway contains our volunteary pathway to move
lateral corticospinal
be able to locate the pathways on the crossection of the SCq
what are the pyramidal pathways
(2)
corticospinal and corticonuclear
what category of pathway is control of musculature or trunk and limbs
(lateral and ) corticospinal
:)
what pathway is equivalent to corticospinal pathway but for synapses in the brainstem
corticonuclear
corticonuclear pathways synapse where
in the brain stem
what does the corticonuclear pathway control
musculature of the head and neck
musculature of the head and neck is associated with what pathway
corticonuclear
extrapyramidal pathways original where
in brainstem
extrapyramidal pathways originate in brainstem but receive cortical input via what and what is their purpose
corticofugal fibers
fibers that project from the cerebral cortex to nuclear masses in the brainstem and spinal cord (go to extrapyramidal)
what are the extrapyramidal pahthways
rubrospinal
tectospinal
reticulospinal
vestibulospinal
UMN cell bodies are located in what cortical motor area
Most in primary
(some in premotor and supplementary)
what is the function for cortical input from premotor and supplementary cortical
=supplemental
aids with planning of complex movement
rubrospinal pathway originates in what part of brainstem
red nucleus
tectospinal pathway originates in what part of brainstem
superior colliculi
reticulospinal pathway originates in what part of brainstem
reticular formation
vestibulospinal pathway originates in what part of brainstem
vestibular nuclei
all of the motor pathways synapse where (first synapse)
in anterior horn or brainstem
all of the motor pathways synapse where (second synapse)
axons will synapse with target tissue (skeletal muscle)
50% of the UMN are located where
in the primary motor cortex
if 50% of UMN are located in the primary motor cortex, where are the others located
premotor cortex
supplementary cortex
true or false, in the motor pathways primary motor cortex is somatotopically organized and explain
true
UMN synapse with LMN at different levels depending on where the UMN cell is located
are motor neurons pseudo unipolar or multipolar
multipolar
true or false: upper motor neurons axons pass thru the posterior limb of internal capsule
true
upper motor neuron axons form the BLANK of the internal capsule
the posterior limb
corticospinal fibers carry info for what region
trunk and limbs
corticonuclear fibers carry info for what region
head and neck
explain the somatotropin arrangement of the internal capsule
corticonuclear fibers (F:face) form the genu of the internal capsule
cortispinal fibers are arranged from rostral (C:cervical) to caudal (L:lumbosacral)
corticonuclear fibers from what aspect of the internal capsule
genu
corticosinal fibers from what aspect of the internal capsule
arranged from from rostral (C:cervical) to caudal (L:lumbosacral)
what is the anterior limb of the internal capsule comprised of
motor and sensory fibers
what is the motor aspect of the anterior limb
motor tracts include the corticofugal fibers
=cortical regulation of extrapyramidal pathways
motor tracts include the corticofugal fibers in anterior limb, what is their purpose
=cortical regulation of extrapyramidal pathways
explain location of UMN of corticospinal pathways axons in midbrain
UMN of corticospinal pathways in cerebral peduncles
UMN of corticospinal pathways in cerebral peduncles is in what aspect of the brainstem
midbrain
UMN of corticospinal pathways in cerebral peduncles, is that more ventral or dorsal
ventral
true or false, in the brainstem, motor pathways are located dorsal
false, ventral
UMN from corticospinal pathway cervical region are more lateral or medial in brainstem
medial
UMN in corticospinal pathway from lumbar region are more lateral or medial in brainstem
lateral
explain location of UMN corticospinal pathway axons in pons
UMN axons of cortispinal pathways in basilar (ventral) region of pons
explain the location of UMN of corticospinal pathway in rostral medulla
UMN axons of corticospional pathways in medullary pyramids
after entering the brainstem, the tracts formed by the UMN axons in the corticospinal pathway are found what region of the brainstem
ventral
true or false, somatotropin organization of motor patwhways is similar throughput and explain
true
cervical more medial
lumbar more lateral
be able to understand the location of corticospinal pathway in brainstem and the associated blood vessels
what blood vessel supplies the corticospinal UMNs in the midbrain
posterior cerebral