Motor I Flashcards
lateral or ventromedial pathways in the spinal cord control voluntary movements
lateral pathways (like corticospinal)
what do ventromedial pathways in the spinal cord control
posture and locomotion
what is the longest tract
corticospinal
if 2/3rds of the corticospinal tract orignates from the frontal motor cortex, where does the other 1/3 come from
the somatosensory cortex
what is the other spinal tract that controls voluntary movements
rubrospinal tract
where does the rubrospinal tract originate from
red nucleus of midbrain (red = rubro)
what differs about a CST lesion as opposed to a CST and RST lesion
a CST lesion alone will see function return in a few months, because RST will pick up the slack
does the rubrospinal tract go up to the cerebrum?
no, it only goes as far as the midbrain (red nucleus)
where is the red nucleus in relation to the substantia niagra
posterior to it
how can one signal through the corticospinal tract create a flexor and extensor motor response
some branches synapse directly with and excite the flexor (antagonist) motor neurons while other branches off that same first CST neuron synapse onto inhibitory interneurons which inhibit the extensor motor neurons
two ventromedial tracts of posture and locomotion
vestibulospional and tectospinal
purpose of tectospinal tract
keeping eyes stable as body moves
purpose of vestibulospinal tract
keeps head and neck stable on body
which of the the 4 ventromedial tracts originates from the vestibular nucleus of the medulla
vestibulospinal tract
where does the tectospinal tract originate
superior colliculi of midbrain
two ventromedial tracts controlling trunk and antigravity muscles
pontine and medullary reticulospinal tracts
which of the ventromedial spinal tracts originates from the pons
pontine reticulospinal tract
what are the four ventromedial spinal tracts and where do they all originate
vestibulospinal - vestibule of medulla
tectospinal - superior colliculi of midbrain
pontine reticulospoinal - pontine reticular formation
medullary reticulospinal - medullary reticular formation
which two tracts originate from the medulla
vestibulospinal and medullary reticulospinal
purpose of pontine and medullary reticulospinal tracts
maintain body posture through trunk and antigravity muscles in limbs using sensory info like balance, proprioception and vision
a more medial LMN will control a proximal or distal muscle
proximal
a more lateral LMN will control a proximal or distal muscle
distal
a LMN where in the spinal cord ventral horn will control axial muscles
medial
what tracts control posture and balance
ventromedial (proximal and axial muscles)
what area is the precentral gyrus
area 4
what is the PMA
premotor area
what is the SMA
supplementary motor area
which area are the PMA and SMA in
area 6
which of the PMA and SMA innervates distal motor units
SMA
true/false the somatotopic motor map is precise
false
where in the brain is the image of the body in space through proprioception and visual inputs formed
in the posterioir parietal cortex
what is area 6 for
working out how to carry an action out
