Spinal Cord Flashcards
(12 cards)
SPINE:
% of vertebral column
articular process - junction of, synovial joint how
central canal - cont, sup (1), inf expand to what where, close where
spinal artery
- anterior: mother, supply, small level
- pos: mother, supply, small level
- segmental: child
- adam: from/mother, side, supplu
- 2/3 of vertebral column
- articular process: junction of lamina & pedicle; synovial joint forms at SAP of inf & IAP of above vertebra
central canal
- cont with medulla’s canal, sup with 4th ventricle
- inf expand to terminal ventricle at conus medullaris; end at filum terminale
spinal arteries
- ant: from vertebral; ant 2/3; T2 & L1
- pos: from vertebral & PICA; pos 1/3; T1-T3
- adamkiewicz: from aorta; unilateral (usually left); lower 2/3
- segmental: give rise to radicular arteries
SPINE: Gray Matter
amount depends on what + greatest level
ant gray
- polar of roots coming out
- med group: level, innervate
- lat group: level, innervate
- central: size, level, nerve, innervate (3)
pos gray
- level
- SG: from to, golgi type, receive (3.1)
- NP: where to SG, what, receive
- ND: name, from to, receive (1)
- VAN: where to ND, level, receive
lat gray
- level, give rise to
- amount depends on muscles innervated; most at cervical & lumbosacral
ANT GRAY
- multipolar roots
- med group: most segments; innervate neck, trunk, abdomen
- lat group: in cervical & lumbosacral; innervate limbs
- central: smallest, in cervical & lumbosacral, forms part of spinal part of accessory nerve; innervate diaphragm (phrenic C3-C5), SCM, traps
POS GRAY
- 2 are throughout
substantia gelatinosa
- from apex of PGC to throughout
- golgi type II
- receive: ascending pain temp pressure, descending from supraspinal levels
nucleus pulposus
- ant to SG, main bulk of cells in PGC
- receive: deep
nucleus dorsalis/clarke column
- C8 to L3-L4
- receive proprioception
visceral afferent nucleus
- lat to ND, T1 to L3
- receive: visceral afferent info
LAT GRAY
- T1 to L2/3
- give rise to preganglionic sympathetic fibers
SPINE: White Matter
why white, in/out of spine, extero vs. proprioceptive info
- white bc myelin
- outer spine
- exteroceptive (from outside body), proprioceptive info (from inside body)
SPINE: White Matter - Ascending (LSTT, ASTT)
start where, lissauer, cervical/sacral fiber, pain/temp fiber
reach (?) between (2) = joined by (2) = what
ascend (1) > (1) med/lat to (?) > 3rd neuron where > end (3)
terminations - cerebral cortex, RF, postcentral, cingulate, insular (purpose)
- start at PRG then ascending & descending fibers travel 1-2 (poslat tract of lissauer)
- sacral later, cervical medial
- pain fiber more ant than temp fiber
- reach medulla between inf olivary nucleus & nucleus of CN5 = join ASTT & spinotectal = spinal lemniscus
- ascend to pos pons -> to tegmentum lat to medial lemniscus -> 3rd order at VPLN & VPMN of thalamus -> end at parietal, postcentral gyrus, cortex
terminations
- cerebral cortex: conscious sensory
- reticular formation: chronic suffering pain
- postcentral gyrus: pain x experience
- cingulate gyrus: pain x emotion
- insular: pain x internal organs & autonomic
SPINE: White Matter - Ascending (LSTT & ASTT)
pain - glutamate detect + released by (2), substance p released by, winding up phenomenon (stimulus = release), a delta vs. c fiber (speed)
analgesia - (3) inhibit what component, stimulate structures (3)
LSTT vs. ASTT - detect (2.2)
- glutamate: detect fast localized; released by a delta & c
- substance p: released by c fiber
- winding up phenomenon: repeated arrival of C fiber stimuli = inc glutamate from C fiber
- a delta (fast; 6-30m/sec), c fiber (slow; 0.5-2m/sec)
analgesia
- serotonin enkephalin endorphin inhibit release of substance p
- stimulate periventricular of diencephalon, periaqueductal of midbrain, nuclei of brainstem
detect
- LSTT = pain temp
- ASTT = touch pressure
SPINE: White Matter - Ascending (DCML)
great sensory decussation - where
start where = divide into (2) + laterality = gracilis & cuneatus (medlat + level)
fasciculus reach (2) = synapse with (2) = become = event = new name
undecussated - name/tract, from nucleus, enter, detect
- great sensory decussation: above pyramidal decussation
- start at PRG = divide into long ascending & short descending at ipsilateral
- fasciculus gracilis: T6 below, more medial
- fasciculus reach nucleus in medulla = synapse with those = become internal arcuate fibers -> decussate = medial lemniscus
undecussated
- cuneocerebellar tract
- nucleus cuneatus that did not cross, towards ICP of cerebellum
- detect proprioception til T6
SPINE: White Matter - Ascending (Spinocerebellar)
ant
- start where > 2nd what where = event > ascend as (1) in (laterality) to (?) > enter (?) > end (?)
- fiber system, if crossed then what happens later
- detect
pos
- start > 2nd where (2) > ascend (laterality) to (?) > enter (?)
- why not til cortex, fiber system, detect
ANTERIOR SPINOCEREBELLAR
- start at PRG -> 2nd order at nucleus dorsalis in base of PGC = decussate -> ascend as ASCT towards medulla (mostly contralateral) -> enter SCP -> end at cortex
- both crossed & uncrossed; if crossed = revert in cerebellum
- detect muscle & joint info
POSTERIOR SPINOCEREBELLAR
- start at PRG -> 2nd order at nucleus dorsalis in base of PGC -> ascend to medulla -> enter ICP
- not reach cortex since nucleus dorsalis is only C8 to L3
- uncrossed
- detect muscle & joint info
SPINE: White Matter - Ascending
spinotectal - end, fiber system, detect (1=3)
spinoreticular - with, end, fiber system, detect (2)
spinoolivary - junction of, synapse, enter, detect
SPINOTECTAL
- end at superior colliculus of midbrain
- crossed fiber system
- detect spinovisual (pain temp tactile)
SPINORETICULAR
- with LSTT, end at reticular formation at midbrain
- uncrossed fiber system
- detect consciousness, diffused pain
SPINO-OLIVARY
- junction of LSTT & ASTT, synapse with inf olivary nucleus at medulla, enter ICP
- detect cutaneous & proprioception to cerebellum
SPINE: White Matter - Descending
from
functions - cortico, reticulo, tecto, rubro, vestib
intersegmental
- from (3), connect, for
- monosynaptic reflex
- descending: from supraspinal nerve centers
- corticospinal: motor
- reticulospinal: reflexes
- tectospinal: visual reflexes
- rubrospinal: facilitate flexion
- vestib: facilitate ext, balance
intersegmental
- from ant pos lat white column
- connects neurons per level
- for spinal intersegmental reflexes
- monosynaptic reflex: only 1 synapse
SPINE: White Matter - Descending (Corticospinal)
start where in where, from % (3.2)
- synapse with (1.1=1)
- converge where > where (UE/LE) > where (UE/LE) > enter = turn into what via what > go where & turn into what > decussate at what level
- if decussate vs. not: formed tract
- internuncial neuron purpose
branch nuclei (3)
branch nuclei: COL
- start as axons of pyramidal cells in 5th layer of cerebral cortex
- 1/3 from area 4, 1/3 from area 6, 1/3 from parietal lobe
- 2/3 from precentral gyrus, 1/3 from postcentral gyrus
journey
- synapse with motor neuron (if large) or internuncial neurons (mostly; synapse with alpha & gamma)
- internuncial neuron: spread afferent impulse to different levels
- converge at corona radiata -> down into internal capsule (pos=LE) -> down into basis pedunculi of midbrain (med=UE) -> enter pons = broken into bundles via transverse pontocerebellar fibers -> enter medulla = group again -> decussate at between medulla & spine
- if crossed = down LWC = lat corticospinal
- if uncrossed = down AWC = ant corticospinal
branch nuclei
- caudate, olivary nuclei, lentiform
- inform subcortical regions about cortical motor activity
SPINE: White Matter - Descending (Reticulospinal)
from pons vs. medulla - via what column, fiber system, tract
enter where
facilitate/inhibit what
pathway for (2)
- from pons: uncrossed fibers descend AWC = pontine reticulospinal tract
- from medulla: crossed & uncrossed fibers descend LWC = medullary reticulospinal tract
- enters AGC
purpose
- facilitate/inhibit alpha & motor neuron
- provide pathway for hypothalamus sympathetic & sacral parasympathetic outflow
SPINE: White Matter - Descending
tectospinal
- start > event > column > end
rubrospinal
- fiber system
- red nucleus (where + level) > decussate where > column > synapse + end
vestibulospinal
- fiber system
- vestibular nucleus (level/where) > column > synapse + end
olivospinal
- start, column
tectospinal
- sup colliculus of midbrain -> decussate -> brainstem -> AWC -> end at AGC
rubrospinal
- red nucleus: in tegmentum of midbrain, level of sup colliculus
- red nucleus -> decussate at pons & medulla -> LWC -> synapse with internuncial neurons at AGC
vestibulospinal
- uncrossed
- vestibular nucleus: at pons & medulla -> AWC -> synapse with internuncial neurons at AGC
olivospinal
- inf olivary nucleus in medulla -> LWC
