Ascending pathways of spinal cord Flashcards
3 diff categories of ascendin info carried by spinal cord
discriminatory - determines type/location/intensity of stimulus
reflexive - activates responses to create behavioral state change with appropriate stereotyped motor responses
Postural - informs or joint, tendon, and muscle position at unconscious level
discriminatory
•Dorsal columns/medial lemniscus (DCML) –Fasciculus gracilis –Fasciculus cuneatus •Anterolateral system –Neospinothalamic
reflexive
•Anterolateral system
–Paleospinothalamic
–[Spinoreticular]
–[Spinomesencephalic
postural
•Spinocerebellartracts –Cuneocerebellar –[Rostral spinocerebellar] –Dorsal spinocerebellar –Ventral spinocerebellar
faster, wider axons
travel to white matter in posterior funuliculi, mechanoreception and tactile, type I and II
slower, thin axon
travel to lamina I to VI in dorsal horn, nociceptive (nociceptors, themoreceptors, mechanoreceptors, and visceral afferents, Adelta and C
discriminatory pathway are how many neurons long
3
postural pathways are how many neurons long
2
discriminatory or non-discriminatory decussates?
discriminatory (pinpointing goes to other side, non-pinpointing does not)
Dorsal Columns also called the
posterior columns medial lemniscus (when in medulla)
dorsal columns type of info
tactile discrimination and conscious prorioception
dorsal columns point of origin
meissners corpuscle merkesl disks pacinian corpuscles ruffinis ending in skin muscle spindles Golgi tendon organs in muscles joints and tendons
dorsal columns cell bodies
dorsal root ganglion
dorsal columns first synapse
nucleus cuneatus or gracilis in caudal medulla
dorsal columns enters spinal cord
medial aspect of dorsal horn, fasciculus cuneatus or gracilis
dorsal columns decussates
internal arcuate fibers ventral to cuneatus and gracilis (becomes medial lemniscus)
dorsal columns second synapse
ventral posteriolateral nucleus (VPL) or thalamus
dorsal columns final destination
primary somatosensory cortex (via internal capsule and corona radiata
where is posterior intermediate sulcus located
thoracic and higher
gracilis is for
lower part of body, lumbar and sacral, nuclei separated by posteiro intermediate septum
cuneatus is for
upper part of body, thoracic and cervical
cuneatus in lumbar
no
how is information organized in posterior columns
lumbar has no posterior intermediate sulcus, info is organized from medial to lateral with medial being lower in body
intermediate sulcus does what
divides gracilis and cuneatus
in medulla fasciculi change to
nuclei
tactile nociceptive and conscious proprioceptive infor are represented where
primary somatosensory cortex
dorsal columns internal arcuate fasciculus
arching fibers
settle at the medial lemniscus
Anterolateral system neospinothalamic is called the
neospinothalamic tract
Anterolateral system type
pain, temp and poorly localized touch
Anterolateral system neospinothalamic point of origin and receptors
free nerve endings (TRP Vchannels) in skin viscera and muscles
Anterolateral system neospinothalamic primary cells bodies
dorsal root ganglion
Anterolateral system neospinothalamic first synapse
Lamina I-VI
Anterolateral system neospinothalamic enters spinal cord and travels
dorsal horn (Lissauer’s Fassciculusto ascend at least 1 segment), after 1stsynapse, travels through anterior white commissure, ascends through anterolateral spinothalamictract
anterolateral system neospinothalamic decussates
spinal cord after first synapse
anterolateral system neospinothalamic second synapse
ventral posteriolateral nucleus (VPL) of thalamus
anterolateral system neospinothalamicfinal desination
primary somatosensory cortex (via internal capsule and corona radiate)
anterolaterl system neospinothalamic organized in spinothalmic tract
CTLS from mdial to posterior
anterolateral system neospinothalamic tidbits
2nd order neuron is highly myelinated
in midbrain anterolateral and medial lemniscus kindof merge so you get pain and tactile in same place
Anterolateral system Paleospinothalamic tract type of info
poorly localized pain, fibromyalgia
Anterolateral system Paleospinothalamic tract point of origin and receptors
Free nerve endings (TRP channels) in skin, viscera, muscles
Anterolateral system Paleospinothalamic tract primary cell bodies
dorsal root ganglion
Anterolateral system Paleospinothalamic tract first synapse
Lamina I-VI
Anterolateral system Paleospinothalamic tract enters spinal cord and travels
dorsal horn (Lissauer’s Fassciculusto ascend at least 1 segment), after 1stsynapse, travels bilaterally, ascends through anterolateral spinothalamictract
Anterolateral system Paleospinothalamic tract decusstes
spinal cord after 1st synapse
Anterolateral system Paleospinothalamic tract second synapse
intralaminar nuclei of thalamus
Anterolateral system Paleospinothalamic tract final destination
bilateral cortex, poorly localized (includes cingulate gyrus and insula (both in limbic lobe, have bad feeling with fibromyalgia))
syrinx in spinal cord
get syringomyelia, a problem with horns which usually aren’t affected bc ther are interior, but fluid filled sac is pressing on them
4 tracts that make up prorioception
- Dorsal spinocerebellar - lower fine component of prorpioception
- Ventral spinocerebellar - lower whole limby prioprioception
- Rostral spinocerebellar(?) - upper limb prioprioception (don’t worry about)
- Cuneocerebellar - upper limb fine prioprioception
Dorsal Spinocerebellar and cunocerebellar type of info
unconscious proprioception
Dorsal Spinocerebellar and cunocerebellar point of origin and receptors
muscle spindles, Golgi tendon in muscle joint and tendons
Dorsal Spinocerebellar and cunocerebellar cell bodies
DRG
Dorsal Spinocerebellar and cunocerebellar 1st synapse
Clarke’s Nucleus (aka nucleus dorsalis) of thoracic cord if dorsal spinocerebellar. Accessory cuneatenucleus in caudal medullaif cuneocerebellar
Dorsal Spinocerebellar and cunocerebellar enters spinal cord and travels
posterior funiculi (thickens with dorsal columns)
Dorsal Spinocerebellar and cunocerebellar decussates
none
Dorsal Spinocerebellar and cunocerebellar second synapse
vermis/paravermis of the cerebellum via inferior cerebellar peduncle
dorsal spinocerebellar and cuneocerebellar final destination
deep cerebellar nuclei (via purkinje cells)
Dorsal spinocerebellar overview
hitchhikes on fasciculus gracilis until l3 then it is visible as dorsal spinocerebellar tract
not visible until l3
cuneocerebellar
hitchhikes on fasciculus cuneatus
clarkes nucleus
DORSAL SPINOCEREBELLAR
•When below C8, unconscious proprioceptiveinfo hitchhikes on posterior column.
–Synapses in Lamina VII
–Visible L3 to C8
•CLARKE’S COLUMN/CLARKE’S NUCLEUS/NUCLEUS DORSALIS
cuneocerebellar above C8
•When above C8, synapses in accessory/external/lateral cuneate nucleus
–Caudal Medulla
which sense is ipsilaterla, contralateral and bilateral
ipsi - proprioception
contra-discriminatory
bilat-reflexes
Dorsal Spinocerebellar and cunocerebellar in cerebellum
intracerebellar pathway
enter through peduncle and are changed to mossy fibers
mossy fibers synapes on granule cells
creating second synapse in the system
granule cell axons go to superior surface and bifurcate and then are called parallel fibers which then synapse on purkinje cells
purkinje cells take axon signal to dcn (deep cerebellar nuclei)
last one is 5th order neuron
Ventral spinocerebellar type o info
unconscious proprioception
Ventral spinocerebellar point of origin and receptors involved
muscle spindle, Golgi tendon organ in muscle joint and tendon
Ventral spinocerebellar cell bodies
drg
Ventral spinocerebellar first synapse
lamina VII then travels to posterior funiculi
Ventral spinocerebellar decussates
immediately in spinal cord
Ventral spinocerebellar second synapse
vermis/paravermisof the cerebellum via superiorcerebellar peduncle. Will then decussate again!
Ventral spinocerebellar final destination
deep cerebellar nuclei (via purkinje cells)
Ventral spinocerebellar hitchkies
hitchhikes on fasciculus gracilis until clarkes nucleus appears (synapes right next to it in lamina VII)
