Medial Pain System Lec17 Flashcards
the medial pain system enable the limbic system to ____
assign emotional weights/salients to stimuli
when asked to rate unpleasantness of a noxious heat simtulus
they activated the ___ and ___
acc and PAG (=medial pain system)
when asked to attend to the location of the thermal stimulus the ____ and ___ are activated
midcingulate and thalamus
(=lateral pain system)
what does the medial pain system include?
- acc
- anterior mCC
- amygdala
- anteriro insula
- midline and intralaminar thalamus
what are the major functions of the medial pain system? (5)
- enable limbic system to assign emotion weight to stim.
- anticipation/learning
- nocifensive behavior
- pain empathy
- pain inhibition
the indirect pathway for pain perception involves what structures
what is the path of the paleospinothalamic tract
Dorsal horn & intermediate gray matter –> Reticular Formation –> MITN, Midline and Intralaminar Thalamic Nuclei –> Cingulate Gyrus
what is the path of the spinoreticulotract (indirect AL)
Dorsal horn & intermediate gray matter –> splits CAUDAL
splits (caudal) Pars Gigantocellularis of Medullary Reticular Formation –> back down to
sympathetics in IML cell column
what is the path of the spinoreticulotract (indirect AL)
Dorsal horn & intermediate gray matter –> splits ROSTRAL
(rostral) Locus Coeruleus and Pontine Reticular Formation –> PVN and MITN
what is the path of the SpinoMesencephalic Tract: (indirect AL)
Dorsal horn & intermediate gray matter –>
** PAG, periaqueductal gray** –> PB (parabrachial) nucleus –> amygdala –> PVN
with the indirect pathway, projections to the
_____ innervate many key
upper and lower limbic/autonomic/motor structures:
- Nucleus ambiguus (breathing and heart rate)
- Gigantocellular RF that projects to the sympathetic IML
- Parabrachial nucleus (PB)
- Paraventricular nucleus of hypothalamus (PVN)
- Amygdala
- Anterior Cingulate cortex
RF, LC, MITN and PAG
PAG and RF regulates ANS via projections to (3)
NTS, DMX, IML
PAG and RF regulates ANS via projections to
NTS, DMX, IML
this circuit modifies ____ in response to pain
modify heart rate, BP, other sensory inputs
what makes up the direct AL pathways
A. Neospinothalamic (classic) Tract
B. Spinotrigeminothlamic (carries pain, temp, tacile from head and neck)
what is the pathway of the neospinothlamic tract (its the classic/lateral spinothlaamic)
Nucleus proprius (laminae III and IV of dorsal horn) --axons cross--\> lateral funiculus --\> VPL of thalamus --\> S1 of postcentral gyrus
what does the The Posteriomedial Pathway carry?
visceral afferents from GI tract
what is the pathway of the posteriomedial pathway
Initially follow autonomic nerves (vagus, sympathetics) –> Lamina X –>
Gracile nucleus –axons cross–> VPL & Central Lateral thalamic nuclei –> Insular &
Cingulate cortex
____ myelotomy - can give relief for chronic, debilitating visceral pain
Posterior midline
____ Creates and Stores “negative memories” associated with pain and distress
locus coeruleus
_____ = any peripheral or central nervous system response to noxious stimuli
- often subconscious
- nerves end in somatosensory cortex (S1, S2)
Nociception
Pain = emotional, ____ experience associated with a noxious stimuli that occurs in the cortex and thalamus
conscious
lateral pain systems is involved in___ and ___
stimulus localization and intensity coding
____ is a key player for acute pain
PAG
Pinched skin + electrical stimulation of ___ =
instant inhibition of nociceptive activity
PAG
- *Central Sensitization** is a major barrier to chronic pain relief.
- Occurs via___ release -
Substance P
Central Sensitization is a major barrier to chronic pain relief.
- Occurs via Substance P release –> long depolarization periods –> Mg block on
NMDA receptor released –> ___
LTP of pain
whay are opiate drugs the msot effective tx for chronic pain relief? what system do they work through?
inhibit substance P release, glutamate, post synaptic nocipcetor
Stress-Induced Analgesia (SIA) - acute, high-level stress can ____ pain sensation (via DNIS)
reduce
why does referred pain occur?
not all visceral noiceptive info project to lamina X in the posteriomedial pathway
some synapses in dorsal horn, so cross wirign can occur
what areas were activated with cue warning of shock (fear conditioning)
what connections does this depend on?
- acc
- medial mtoro areas, SMA and CMA
- MITN thalamus
depends on connections with the amygdala and thlaamus
nocifensive means ___
pain avoidance
seeing pain ifnlicted on others activates what pain system
medial pain system and lateral pain system
anterior cingulotomy for chronic pain relief
abolishes what?
nocifensive and many limbic/auntomic responses
anterior cingulotomy for chronic pain relief
what remains nml?
ability to localize the noxious stimulus (they can feel stimulus but are not bothered by it)
lesions to ventroposterior nucleus and somatosensory cortex results in
imapirs localization of pain, but not the perception
relief of pain is tied to activation in ___ and ___
perigenial and pag
“Placebo” effect of telling patients what to expect after surgery, how to relax, etc: those who received pain counseling self-administered less morphine.
what was involved?
the ACC
substance p release in the spinal cord leads to –>
release of Mg block of NMDA receptor
central sensization si maldaptive learning in the
medial pain system
Glia maintain central sensitization by releasing
pro-inflammatory factors
