somatosensory II Flashcards
spinothalamic tract projects to
VPL and intralaminar nuclei of thalamus
spinomesencephalic tract projects to
periaquaductal gray and tectum
spinoreticular tract projects to
reticular formation of medulla, pons, midbrain
spinobulbar tract projects to
brainstem nuclei
spinohypothalamic tract projects to
hypothalamus
allodynia
body says “turn down for what?!”
this is CENTRAL SENSITIZATION so where normal sensory information (like touch) can be percieved as pain.
sensory neurons enter the dorsal roots and bifurcate.
whats medial?
whats lateral?
medials are more MEATY (large fibers); synapse on lamina III-V
laterals are small fibers; synapse on lamina I, II, V
senses in ALS that are different from PCML system
hypesthesia, paresthesia, anesthesia
feel the burn: (pain and temp)
what are the fast burners? why?
lamina?
A delta are lightly myelinated
1 and 5
feel the burn: (pain and temp)
what are the slow burners? why?
lamina?
C are unmyelinated
1 and 2 and 3 (specific tracts in ALS have different lamina for C fibers)
lamina 2/3 is responsible for
cock-blocking the incoming pain signal.
SUBSTANTIA GELATINOSA it is the gate keeper for which signals are painful. pain is modulated at the level of the dorsal horn
lamina of nucleus proprius
4,5,6
what is a triple response to pain
you get fast pain sensation(A delta). slow pain sensation(C fibers), and inflammation
what is the role of hypothalamus in pain
connects the pain to emotion and ALS
=> this is is why people like S&M
what is the role of the insular cortex in pain
connections give you the “dislike” part of feeling pain
what is the role of the hippocapus in pain? amygdala?
hippocampus does pain memory
amygdala does the fear and anxiety part of pain
you get stuck by a needle. what is the role of substance P in pain
1 - substance P (a peptide) is in nerves
2 - it is released at the site to bind with arterioles leading to the FLARE RESPONSE
3 - it binds to mast cells for inflammation/histamine - WHEAL RESPONSE
what neurons DESCEND and synapse on lamina 2/3? why?
RAPHESPINAL pain modulation!
remember?! thats what happens in those two lamina!!
I sprayed you with pepper spray.
what system is it?
fibers?
synapse?
paleospinothalamic tract
C fibers
lamina II and III
you accidentally got warming lube on your face what system is it? first order neurons? second order neurons? decussate?
anterior trigeminothalamic tract is most important
1 = trigeminal ganglion
2 = spinal trigeminal nucleus
decussate to form the ventral trigeminothalamic tract
what are the cock-blocker cells of the dorsal horn?
enkephalinergic interneurons. they work PRE-synaptically.
opiates are also cock-blockers. How?
made in the PAG, they “go down” on the raphe nucleus so that when the pain signal comes in, it gets turned off
serotonin is a ____
cock-blocker. but its for the primary aferents. aka the pain signal gets to the spinal cord, but serotonin kills the mood
trans cutaneous nerve stimulation treatment is based off of
gate control theory
rhizotomy is
transection of dorsal roots
ventral trigeminothalamic tract mediates?
pain and temp sensation from the face and oral cavity
dorsal trigeminothalamic tract mediates?
tactile discrimination and pressure sensation from the face and oral cavity (meissner/pacinian corpuscles)
afferent/efferent limb of corneal reflex
ophthalmic n (V1) facial n
afferent/efferent limb jaw jerk reflex
mandibular n (V3) mandibular n (V3)
afferent/efferent limb tearing (lacrimal) reflex
ophthalmic n (V1) facial n
afferent/efferent limb oculocardiac reflex
ophthalmic n (V1) vagal n
