Sensorimotor Tracts Flashcards
what are the pyramidal tracts?
lateral and anterior corticospinal tracts
what are the extrapyramidal tracts?
rubrospinal, reticulospinal, and vestibulospinal tracts
what are the 2 spinocerebellar tracts?
posterior and anterior spinocerebellar tracts
which pathways are motor/descending/efferent?
pyramidal and extrapyramidal tracts
which tract contains the longest neurons in the body?
fasciculus gracilis
which tract is responsible for LE discriminative sensory?
fasciculus gracilis
what are the components of epicritic (discriminative) sensory?
deep touch, 2pt and vibration, conscious proprioception
where does fasciculus gracilis enter the spinal cord?
dorsal root ganglion
in what part of the spinal cord does fasciculus gracilis travel?
white matter of medial dorsal column pathway
where do the primary and secondary neurons synapse in fasciculus gracilis?
medulla
where does the secondary neuron of fasciculus gracilis crosses midline?
medulla
where do the secondary and tertiary neurons synapse in fasciculus gracilis?
thalamus
what is the ultimate destination of fasciculus gracilis?
sensory cortex
which tract does UE discriminative sensory, including fine touch, 2pt and vibration discrimination, conscious proprioception, stereognosis?
fasciculus cuneatus
with fasciculus cuneatus, where does the primary neuron enter the spinal cord?
dorsal root ganglion
with fasciculus cuneatus, where do the primary and secondary neurons synapse?
medulla
with fasciculus cuneatus, where does the secondary neuron cross midline?
medulla
with fasciculus cuneatus, where do the secondary and tertiary neurons synapse?
thalamus
with fasciculus cuneatus, where does the tertiary neuron ultimately end up?
sensory cortex
which tract is responsible for unconscious proprioception?
spinocerebellar tract
what are golgi tendon organs sensitive to?
pressure
what are muscle spindles sensitive to?
stretch
with the spinocerebellar tract, where does the primary neuron enter the spinal cord?
dorsal root ganglion
with the spinocerebellar tract, where does the primary neuron travel when heading towards the brain?
gray matter
with the spinocerebellar tract, where do the primary and secondary neurons synapse?
dorsal horn of spinal cord
with the spinocerebellar tract, where does the secondary neuron ultimately synapse?
inferior cerebellar peduncle
which tract is protopathic (protective) and detects pain and temperature?
lateral spinothalamic tract
what are the receptors that detect temperature?
free nerve endings
where does the lateral spinothalamic tract enter the gray matter of the spinal cord?
dorsal horn of spinal cord
with the lateral spinothalamic tract, where does the tract cross midline?
within gray matter of spinal cord
with the lateral spinothalamic tract, where do the primary and secondary neurons synapse?
within gray matter of spinal cord
with the lateral spinothalamic tract, what does the secondary neuron travel through as it heads towards the thalamus?
lateral white matter
with the lateral spinothalamic tract, where do the secondary and tertiary neurons synapse?
thalamus
with the lateral spinothalamic tract, where does the tertiary neuron ultimately end up?
sensory cortex
which tract is protopathic and detects coarse touch (pressure, pleasant touch, tickle, itch)?
ventral spinothalamic tract
with the ventral spinothalamic tract, where does the primary neuron enter the spinal cord?
dorsal horn
with the ventral spinothalamic tract, where does the tract cross midline?
within gray matter of spinal cord
with the ventral spinothalamic tract, where do the primary and secondary neurons synapse?
within gray matter of spinal cord
with the ventral spinothalamic tract, where do the secondary and tertiary neurons synapse?
thalamus
with the ventral spinothalamic tract, where does the tertiary neuron ultimately synapse?
sensory cortex
which tract is responsible for voluntary motor control and fractionation of movement?
corticospinal tract
with the corticospinal tract, what is the origin of the primary neuron?
M1
with the corticospinal tract, through what 2 structures does the primary neuron pass before entering the brainstem?
corona radiata, then internal capsule
with the corticospinal tract, where do the primary and secondary neurons synapse?
medulla
where does the corticospinal tract split to descend in 2 tracts?
medulla
what are the 2 corticospinal tracts of the secondary neuron?
ventral and lateral corticospinal tracts
10-20% of fibers of the corticospinal tract stay ipsilateral with this tract
ventral corticospinal tract
80-90% of fibers of the corticospinal tract cross contralaterally with this tract
lateral corticospinal tract
where does the secondary neuron of the ventral corticospinal tract ultimately synapse?
ventral horn of spinal cord
with the lateral corticospinal tract, where do the secondary and tertiary neurons synapse?
ventral horn
with the lateral corticospinal tract, at what point does the UMN synapse with the LMN?
synapse of secondary and tertiary neurons in ventral horn
with the lateral corticospinal tract, where does the tertiary neuron ultimately synapse?
effector muscle
which tract extends the wrist and fingers?
rubrospinal tract
with the rubrospinal tract, what is the origin of the primary neuron?
red nucleus of midbrain
where does the rubrospinal tract cross midline?
midbrain
with the rubrospinal tract, through what does the primary neuron travel as it descends?
lateral column
with the rubrospinal tract, where do the primary and secondary neurons synapse?
ventral horn
with the rubrospinal tract, where does the secondary neuron ultimately synapse?
effector muscle
with the reticulospinal tract, what is the origin of the primary neuron?
midbrain
which tract is responsible for postural control, overall muscle tone, bilateral motor control, and arousal?
the reticulospinal tract
what is the structure in the brainstem that belongs to the reticulospinal tract?
reticular formation
at what point does the reticulospinal tract become 2 pathways?
ventral horn
which pathway of the reticulospinal tract is responsible for control of antigravity extension (posture)?
medial reticulospinal tract
which pathway of the reticulospinal tract is responsible for control of axial extension (bilateral gross motor, stepping pattern generator)?
lateral reticulospinal tract
where does the primary neuron of the medial reticulospinal tract ultimately synapse?
white matter of spinal cord
with the lateral reticulospinal tract, where do the primary and secondary neurons synapse?
white matter of spinal cord
with the lateral reticulospinal tract, where does the secondary neuron ultimately synapse?
effector muscle (leg)
which tract is responsible for balance, posture, and head stabilization?
vestibulospinal tract
which pathway of the vestibulospinal tract controls the neck and upper back?
medial vestibulospinal tract
which pathway of the vestibulospinal tract controls the trunk and lower back posture?
lateral vestibulospinal tract
with BOTH vestibulospinal tracts, where do the primary neurons originate?
medulla
with the medial vestibulospinal tract, where do the primary and secondary neurons synapse?
ventral horn
with the medial vestibulospinal tract, where does the secondary neuron ultimately synapse?
neck/upper back
with the lateral vestibulospinal tract, where do the primary and secondary neurons synapse?
ventral horn
with the lateral vestibulospinal tract, were does the secondary neuron ultimately synapse?
trunk/lower back
