MSK Pain Flashcards
Acute pain is primarily ___
nociceptive (somatic> visceral)
Compare Nociceptive vs neuropathic pain
Nociceptive: somatic or visceral, activation of nociceptive nerve fibers
Neuropathic: persists and has become disengaged from noxious stimuli or the healing process
Describe Somatic pain
- arising from skin, bone, joint, CT or muscle due to MSK condition, inflammation or mechanical problems
- Decribed as throbbing and well localized
Describe visceral pain
- arising from internal organs
2. referred pain or well localized
Describe neuropathic pain
- burning/tingling/shock like
- shooting
- exaggerated response to normal painful stimuli (hyperalgesia)
- and/or painful response to nomrally nonnoxious stimuli (allodynia)
What effect do prostaglandins have on chemoreceptors
do not stimulate them directly, but act to increase the sensitivity of the nerve endings to the other neurochemicals resulting in an increased pain response for any given stimulus
- NSAIDs inhibit PG synthesis
- GC decrease PG synthesis and have anti-inflammatory effects
How do local anesthetics help with blocking transduction-transmission of pain stimulus
Local anesthetics block VSSC along the spinothalamic tract and interrupt the transmission of pain impulses at any site in the pain pathway
Somatosensory cortex receives input from ___ and is involved in sensory-discriminative aspects of pain (where and how much?)
ascending pathway of spinothalamic tract
Stimulation gives rise to localized, sharp, stinging pain via ___ fibers. Describe the adaptation of these fibers
rapidly conducting A-δ nerve
*The pain receptors in this pathway adapt very little allowing the person to remain apprised of damaging pain-inducing stimuli as long as it persists
info from ___ + ___ forms subjective pain experience
discriminatory (somatosensory cortex) +
emotional (limbic system)
compare different pain nerve fibers
A-delta: sharp, stinging, fast conducting, little adaptation
C: slow, diffuse, achy,
How do opioid analgesics affect pain
- act on dorsal horn of SC to alter subjective reaction/response to pain (emotional- can feel pain but don’t care)
- act on endogenous enkephalin receptors at this site resulting in a subsequent decrease in ascending pain impulse transmission. (raises the pain threshold and decreases the patient perception of pain (intensity level))
The descending pain-inhibitory pathway originates in neurons of the ___ and descends (i.e., from the CNS to the periphery) to synapse on primary pain afferent neurons in the dorsal horn of the spinal cord (C and A-δ).
-The neurotransmitters that are released from [__] neurons include:
periaqueductal gray region (PAG) of the midbrain
PAG
- opioid peptides (enkephalins),
- norepinephrine, and
- serotonin.
Uses for:
Aspirin (acetylsalicylic acid, ASA) / Nonsteroidal anti-Inflammatory Drugs (NSAIDs) / Acetaminophen, COX-2 Selective agents
- most frequently used drugs for pain relief (analgesia)
- all but acetaminophen are also effective for tx of inflammation
- used as antipyretic or antiplatelet (ASA) actions
How do local anesthetics block pain
block all sensory afferents
*commonly used in combo w/ vasoconstrictors such as epi