Blake: Pain Flashcards
An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage
Pain
Four forms of etiology-based pain
nociceptive
neuropathic
cancer
psychogenic
Two types of nociceptive pain
somatic pain
visceral pain
Pain arising from bone, muscle, ligament, subcutaneous tissue, or skin. (e.g. ankle sprain, arthritis)
somatic pain
Pain arising from organs such as lung, liver, bowel, etc. (Nociceptive pain; e.g. cholecystitis, nephrolithiasis)
visceral pain
Pain arising as a direct consequence of a lesion or disease affecting the somatosensory system (e.g. radiculopathy, CRPS)
neuropathic pain
Both nociceptive and neuropathic pain. Common in cancer related pain. (e.g. chest wall pain from lung cancer)
mixed pain
What are some pain assessment scales?
verbal pain intensity scale
0-10 numeric pain intensity scale
visual analog scale
faces scale
Total number of cases of low back pain excluding back pain (what?)
1, 765,000
Components of comprehensive treatment plan
- biological approaches
- psychological intervention
- social/rehabilitative issues
- pharm/nonpharm therapies
- mood disturbances, coping skills, sleep disturbances
- family/social relations, work issues, physical rehabilitation
What does “noci” mean?
to injure, hurt, harm, harmful
Sensory receptor that responds to noxious stimuli
When active or activated, can contribute to the experience of pain
nociceptor
Pain fibers - usually unmyelinated axons and small cell body diameters
C fibers and A gamma fibers
An important receptor in pain research - activated by Capsaicin, which is contained in chili peppers.
TRPV1
What’s hyperalgesia?
heightened sense of pain to noxious stimuli (moves stimulus intensity curve to the left)
What’s allodynia?
pain resulting from normally painless stimuli
Predominant location of excitatory neuropeptide input from primary afferent neurons
lamina I and II
What is lamina II?
substantia gelatinosa
Spinomesencephalic neurons target the midbrain and the (blank) - very important in the regulation of nociception
periaqueductal grey (PAG)
Located in the midbrain – key structure in relaying descending pain modulation via RVM nuclei
periaquaductal grey matter
Portion of the diencephalon to which all (but olfactory) sensory systems send signals
thalamus
All sensory systems send signals to the thalamus, and they are directed to the specific cortical representation areas. What are the two pain systems associated with the thalamus?
lateral and medial pain systems
Two portions of the cerebrum
sensory cortex
limbic system
Activation of Aβ fibers (Large diameter afferents) produces an inhibitory effect on the processing of signals from Aδ and C-fibers
E.g. Rubbing or massaging injured parts of body in order to achieve pain relief
Gate Control Theory
the idea that physical pain is not a direct result of activation of pain receptor neurons, but rather its perception is modulated by interaction between different neurons
Gate Control Theory
Phenomenon whereby repeated electrical C-fiber activation leads to a sequential increase in the number of action potentials evoked by each stimulus
Wind up
Portion of the midbrain that represents a site that provides descending influences on spinal processing
periaquaductal grey (PAG)
Excitatory amino acid neurotransmitters that act on ligand-activated ion channels
glutamate
aspartate
Excitatory amino acid activated ion channels
AMPA
NMDA
Responsible for “fast” nociceptive transmission
AMPA
Responsible for sustained depolarization
NDMA
2 phenomena linked to NMDA receptor activation
“Wind-Up” – increasing 2nd order neuron responses to repeated stimuli of equal intensity
“Central sensitization” – decreased thresholds for response and/or increased vigor of responses
Excitatory neurotransmitters via channel activation/2nd messenger system
CGRP
Substance P
effects related to peripheral vasodilation (migraines?)
Augments nociception
CGRP
co-released with glutamate; modifies the gain
Also important in neurogenic inflammation, where it is released from peripheral axons and produces local tissue effects
Substance P
Neurotransmitters from interneurons
Inhibitory amino acids (IAA’s): GABA
Glycine
Opioids
Acetylcholine
Neurotransmitters from supraspinal sources
serotonin: 5HT receptor of relevance to pain
norepinephrine: alpha 1 or 2 receptors
