Pain management is a high priority in our health care system
• person in pain often experiences the pain as an all-consuming reality and wants only
... [Show More] one
intervention—pain relief.
THE PAIN EXPERIENCE
• It is one of the human body’s defense mechanisms that indicates the person is
experiencing a problem.
• “Pain is whatever the experiencing person says it is, existing whenever he (or she) says it
does.”
TRANSDUCTION
• The activation of pain receptors is referred to as transduction.
o Involves conversion of painful stimuli into electrical impulses that travel from the
periphery to the spinal cord at the dorsal horn.
• The nociceptors, or peripheral receptors, respond selectively to specific noxious stimuli
• The prolonged effect of pain stimuli acting on the central nervous system (CNS) can lead
to sensitization, meaning that the threshold for activation of pain is lowered
o At that point, even harmless stimuli can trigger pain; pain signals are faster and
feel more intense.
• Other substances are also released that stimulate nociceptors or pain receptors. These
include bradykinin, prostaglandins, and substance P:
o Bradykinin, a powerful vasodilator that increases capillary permeability and
constricts smooth muscle, plays an important role in the chemistry of pain at the
site of an injury even before the pain message gets to the brain. It also triggers the
release of histamine and, in combination with it, produces the redness, swelling,
and pain typically observed when an inflammation is present.
o Prostaglandins are important hormone-like substances that send additional pain
stimuli to the CNS.
o Substance P sensitizes receptors on nerves to feel pain and also increases the rate
of firing of nerves.
• Prostaglandins, substance P, and serotonin (a hormone that can act to stimulate smooth
muscles, inhibit gastric secretion, and produce vasoconstriction) are neurotransmitters,
substances that either excite or inhibit target nerve cell [Show Less]