Pain Flashcards
What are 4 theories of pain?
- specificity theory of pain
- intensity theory of pain
- pattern theory of pain
- gate control theory of pain
_____ fibers = myelinated, localizes sharp first pain
Ad
Ad fibers = intense _______ and _______ stimulation
mechanical; thermal
___ fibers = unmyelinated, poor localized diffuse second pain.
C
C fibers = code for what 3 things?
- mechanical
- thermal
- chemical
Tissue injury causes the release of what 4 things, which stimulate the C fibres?
- bradykinin
- 5-HT
- protaglandins
- K+
Active C fibers release _____ and substance ___ which stimulates mast cells, which release histamine.
CGRP; P
CGRP and substance P released by C fibers causes the ______ of blood vessels.
dilation
A delta and C fibers synapse in the _____ horn of the SC in a complex network of projection ______ and _______.
posterior; neurons; interneurons
The posterior horn is the first site of pain _______.
modulation
What fibers synapse on nociceptor specific neurons?
A delta and C fibers
What fibers synapse on the WDRN?
Ad, Ab, and C
________ receive diverse input, and they play a role in pain modulation.
interneurons
____ neurons can fire APs in a graded fashion.
WDR
WDR neurons are dependent on __ fiber signalling.
C
____-__ can leave to sensitization.
wind up
Wind-Up refers to the amplification system that responds to repeated __ fiber activity
C
The input of the Ab fiber onto the interneuron leads to (more/less) inhibition of the WDRN.
MORE
The input of the C fibre onto the interneuron leads to (more/less) inhibition of the WDRN.
LESS
The ____-____theory has to do with prioritizing pain.
gate-control
________ system = comprises all fibers carrying pain and temp from the SC to the brainstem and thalamus.
anterolateral
_____ tract comprises only the fibers projecting from the spinal cord to the thalamus.
spinothalamic
What are the 5 ascending pain systems that are part of the anterolateral system?
- spinothalamic
- spinomesenchephalic
- spinoreticular
- spinobulbar
- spinohypothalamic
Where does the spinomesencephalic tract go to?
PAG in midbrain
The _____ system of the spinothalamic tract = affective motivational component
medial
The ______ system of the spinothalamic tract = discriminative localization of pain
lateral
Where does the medial system of the STT go to?
limbic system association cortices
Where does the lateral system of the STT go to?
primary somatosensory cortex
Convergence of pain afferents and descending modulation occurs in the _____ horn.
posterior
What are the 3 types of chronic pain?
- nociceptive/inflammatory pain
- neuropathic pain
- idiopathic pain
Athritis pain is an example of chronic _______ pain.
inflammatory
postherpetic neuralgia = example of chronic _________ pain.
neuropathic
________ = idiopathic pain
fibromyalgia
What are 3 possible mechanisms that occur in idiopathic pain?
- central sensitization
- allodynia
- hyperalgesia
What are 2 maladaptive mechanisms that occur in chronic pain?
- peripheral
2. central
______ sensitization = wind-up, overexpression of receptors
peripheral
______ sensitization = changes in ion channel expression, changes in NT receptors, disinhibition
central
What are 3 things that occur in central sensitization?
- parenthesis, dyesthesias
- hyperalgesia
- allodynia
_______ and _______ = increased spontaneous activity
parethesias; dyesthesias
_______ = reduced threshold for pain perception
hyperalgesia
_______ = non-noxious stimuli are interpreted as pain
allodynia
Allodynia = misdirected sprouting of ___ _____ fibres.
A beta
_____ pain = burning, shooting, electrical
neuropathic
______ pain = squeezing, throbbing, aching
nociceptive
______ pain = pain perceived in regions innervated by nerves other than those that innervate the site of noxious stimulation
referred
_______ pain = where stimulation of a sensory nerve along it’s path may induce pain that is projected to the tissue innervated by the stimulated nerve.
projected
For viscera, information about physiological functions travel with _______ fibres.
parasympathetic fibers
For viscera, information about pain travels with ______ fibers.
sympathetic
Referred pain can be from visceral nerve to ______ area, and it can be somatic nerve to ______ area.
somatic (dermatome)
