Spinal cord anatomy Flashcards
how do action potentials enter the spinal cord
how do the neurons split up
cell bodies in the dorsal root
enters from dorsal horn, split up and syapse onto many neurons
come out of ventral horn
Two descending tracts
two ascending tracts
white or grey matter?
LCST= Lateral corticospinal tract, distal muscles
VCST= Ventral corticospinal tract, proximal muscles
VST= ventral spinothalamic tract, pain, temp
DCML= dorsal column medial lemniscus, mechanoreceptors, cutaneous, joint, GTOs
Descending spinal tracts
what side does act pot come from and controls what side
come from M1, primary motor cortex, Betz cells bring it out
at medullary pyramids, DECUSSATE onto other side
from ventral corticospinal tract(core muscles), the ipsilateral side— to lateral corticospinal tract(distal muscles)
Red: where to, what tract
Peach: where to, what tract
Yellow: where to, what tract
caudal medulla
Red: hand and arm. LCST
PEACH: trunk—- VCST—-no decussate, innervate bilaterally
Yellow: none
decussate at caudal medulla
LCST
where are the synapses
GOES TO DISTAL MUSCLES
act potential come down from M1, reach caudal medulla and decussate onto the other side
contralateral
continues down spinal cord until reaches place it needs to leave to get to limbs
at the caudal medulla, and on the alpha motor neuron
VCST
where are the synapses
GOES TO PROXIMAL MUSCLES
Act potential come from M1
goes thru caudal medulla
stays ipsilateral
innervates bilateral when needs to
both sides and to core or proximal muscles
at the area of spine it leaves from
A-beta axon
A-delta axon
C axon
A-BETA— cutaneous receptors, stay on one side
A-delta and C– pain and thermoreceptors
- in thru dorsal, decussate where it enters
VST
ventrospinothalamic
where are the synapses
info from Adelta or C
pain or thermoreceptors
come in and decussate WHERE IT ENTERS
go up the spinothalamic tract to S1
synapse where it enters, then at thalamus, and S1
DCML medial lemniscus pathway
where are the synapses
info from mechanosensory inputs, spindles, joints, GTOs, cutaneous
goes into the dorsal horn and the DCMLT
goes up on the contralateral side to the S1
decussate and synapse at the brainstem, then at the thalamus, and lastly at S1
