Chapter 14 - Pain and Temperature Flashcards
Pain Definition
dysfunction of general or specific senses
Pain is a ________ phenomenon
protective
Is pain subjective or objective? Why?
subjective, it is not measurable
The physical, cognitive, and emotional interactions of pain make it very ________
complex
How did McCaffery define pain?
“Whatever the experiencing person says it is, existing whenever they say it does.”
Variations in temperature can signal _________
disease
_______ is a common symptom of dysfunction
fever
What is often the first symptom of infectious or inflammatory conditions?
fever
Specific Pain Theory =
receptors
The specific pain theory says that injury activates specific pain ________ to the brain
receptors
The specific pain theory says that pain intensity is related to…
direct association with tissue injury ie. cutting hand with knife hurts more than finger prick
What is the problem with the specific pain theory?
it doesn’t account for emotional pain
Gate Control Theory =
spinal cord
The gate control pain theory explains _____________ aspects of pain
multidimensional
The gate control pain theory uses the spinal cord as a gate to control transmission to the _____
CNS (brain)
The Neuromatrix Theory =
brain
In the neuromatrix theory, stimuli trigger _______ of nerve impulses, but don’t produce them
patterns
Where are patterns of nerve impulses taken from?
genetic, psychological, or cognitive EXPERIENCES
What is an example of pain being felt without experience?
phantom limb
The afferent pathway brings the pain impulse from the _______ to the _______
epithelial receptors to the CNS
What part of the body interprets pain?
the brain and spinal cord
The efferent pathway brings the pain response from the _______ to the _________
CNS to the response organ (ie. muscle)
Nociception
processing of harmful stimuli through the nervous system
Nociceptors are _____ nerve endings in the ___________ PNS
free; afferent
What is larger: A delta or C fibres?
A Delta
Which of A delta or C fibres are myelinated?
A delta are myelinated, C fibres are not
_______ fibres access the large spinal cord tracts
A Delta
______ fibres access the small spinal cord tracts
C fibres
Which type of fibres produce the initial fast and sharp pain?
A delta
Which type of fibres produce the latter dull and throbbing pain?
C fibres
What is the “activation of nociceptors”?
transduction
What is the “conduction to dorsal horn and up the spinal cord”?
transmission
A transducer is…
a device that converts variations into an electrical signal
What does the sensory discriminative system do?
identify presence, location, and intensity of pain
What part of the brain is involved in sensory discrimination?
somatosensory cortex
What does the motivational-affective system do?
determines avoidance and emotional responses
What parts of the brain are involved in the motivational-affective system?
reticular formation and limbic system
The cognitive-evaluative system is involved with the ________ pain experience
learned
Pain Perception
conscious awareness of pain
The _______ and _______ systems are involved in pain perception
reticular and limbic
Pain Threshold
lowest recognizable intensity of pain
Pain Tolerance
highest intensity of pain a person can endure
**Pain tolerance ________ with repeated exposure
decreases
The concept of perceptual dominance says that intense pain at one location _______ the threshold at another location.
increases
What do pain modulation mechanisms do?
increase or decrease pain transmission
What are two triggers that initiate excitatory neurotransmitters?
tissue injury and chronic inflammation
What do excitatory neurotransmitters do?
reduce nociceptor activation threshold (increase their responsiveness)
Name 4 Examples of Excitatory Neurotransmitters
-substance P
-glutamate
-histamine
-prostaglandins
What do inhibitory neurotransmitters do?
reduce the transmission of a pain signal
Name 5 Examples of Inhibitory Neurotransmitters
-opioids
-GABA
-cannabinoids
-serotonin
-norepinephrine
What does the descending inhibitory pathway do?
releases endorphins to inhibit the pain signal
Endorphins (opiates) are a mixture of _______ and _________
endogenous and morphine
Where do endorphins bind?
opiate receptors
Opiate receptors are G _________ coupled
protein
Morphine-like neuropeptides are responsible for what sensation?
well-being
What do morphine-like neuropeptides bind with? What do they do?
opioid receptors; inhibit pain impulses
Cannabis produces a ________ containing cannabinoids
resin
Cannabinoids are an analgesic meaning…
they relieve pain
Cannabinoids have _________ and ___________ drawbacks
psychoactive and addictive
When was Cannabis legalized in Canada?
2020
Endocannabinoids are synthesized in the body from ___________ to modulate pain
phospholipids
How does alcohol relieve pain?
depressing the CNS
In 1200 to 1500 England a potion called ________ was used as an anesthetic.
dwale
Dwale Ingredients
-alcohol base
-bile
-opium
-lettuce
-hemlock (highly toxic plant)
-vinegar
When was Ether created?
1840
When was the first pain free surgery performed? Where?
1846 in the amphitheatre at Mass Gen
What is another name for acute pain?
Nociceptive pain
Acute pain is a protective mechanism that…
alerts to harmful conditions and mobilizes person to relieve it
How long does acute pain last?
minutes to weeks
3 Types of Acute Pain:
- somatic
- visceral
- referred
Where does somatic pain occur?
localized to skin, joints, muscles
What fibres are responsible for sharp and localized somatic pain?
A delta
What fibres are responsible for dull, throbbing somatic pain?
C fibres
Where does visceral pain occur?
internal organs and body cavity lining
Is visceral pain localized?
no, it is more achy
Which fibres are responsible for visceral pain?
C fibres
Where is referred pain felt?
distant to the point of origin
Which receptors converge on the same ASCENDING neuron to provide referred pain?
cutaneous and visceral
Why does referred pain happen?
the brain can’t distinguish which receptors are affected
Why is referred pain often felt on the skin?
the skin has more receptors
Persistent pain is aka __________ pain
intractable
How long does persistent pain last?
3-6 months
What is the purpose of persistent pain?
there isn’t one
Persistent pain can be _________ or __________
-ongoing ie. back pain
-intermittent ie. migraine headaches
Studies on persistent pain show a change in the _______ that show a _______ ability to cope with pain
brain; reduced
Neuropathic pain is caused by a dysfunction of the _________ system
nervous
Neuropathic pain results from ______ term changes in pain _________ and ________
long; pathway; processing
Neuropathic pain ________ pain to a burning, shooting, tingling sensation
amplifies
Neuropathic pain is characterized by an increased ____________ to stimuli, painful or not
sensitvity
__________ (increased pain capacity) is a characteristic of neuropathic pain
hyperalgesia
Hyperalgesia
increased capacity to feel pain
Analgesia
absence of pain
Fever Definition: the _________ resetting of __________ thermostat to higher levels in response to exogenous or endogenous pyrogens
temporary; hypothalamic
Pyrogen
substance that produces fever when released into blood
Pyro
related to fire
Exogenous
growing from or on the outside
Endogenous
growing/originating within
Exogenous Pyrogens
pathogens
Endogenous Pyrogens
TNF-a, IL-1, IL-6
__________ pyrogens cause the release of __________ pyrogens
exogenous; endogenous
How do pyrogens raise the thermal set point?
inducing hypothalamic synthesis of prostaglandin E2 (PGE2)
How do prostaglandin’s increase temperature?
increased heat production and conservation
Heat conservation through cutaneous ___________ and decreased sweating makes the individual feel ______
vasoconstriction; colder
How long does the body maintain the increased temperature?
until the fever breaks and the original set point is reinstated
Pathogen activates the release of m_________ that release ___________ and signal the temperature regulating centre to release ______ to raise the set point
macrophages; cytokines (TNF-a, IL-1, IL-6); PGE2
How is heat generated after the set point is raised?
-increased muscle contraction
-shivering reflex
-increased metabolism
Fever kills __________ and affects their growth an replication
microorganisms
Fever decreases serum levels of ______ needed for bacterial growth
minerals
Increased temperature causes ___________ breakdown which prevents…
lysosomal; viral replication
Fever enhances ________ and antiviral _________
phagocytosis; interferon
Hyperthermia
elevation of body temp without an increased hypothalamic set point
What are 3 risks of hyperthermia?
-nerve damage
-protein coagulation
-death
Heat cramps are severe________ (sporadic) cramps
spasmodic
Heat cramps follow a) prolonged ________ and b) associated ______ loss
sweating; sodium
How many mmol of sodium are in a L of sweat?
40-60
Who is at risk for heat cramps?
-those not accustomed to heat
-those performing strenuous work in warm climates
S&S of Heat Cramps
-↑ core temp
-rapid pulse
-↑ BP
Heat exhaustion can result from high _____ or ___________ temperatures
core or environmental
Heat Exhaustion: intense vasodilation and sweating leads to:
-dehydration
-hypotension (low BP)
-tachycardia (fast HR)
Heat exhaustion manifests as: ______, _________, ________, and __________
dizziness, weakness, nausea, and confusion
Heat stroke can be ________
lethal
What body temperature does nerve damage and convulsions occur at?
41℃
What body temperature does death occur?
43℃
What is the normal core body temperature?
37℃
Hypothermia occurs when the body temp is less than ____℃
35
During hypothermia, what is produced inside cells that causes cellular rupture?
ice crystals
Tissue hypothermia: ________ metabolic rate, ______ blood viscosity, ________ blood coagulation and vasoconstriction
slows; increases; facilitates
When is therapeutic hypothermia used?
during surgery
Why is therapeutic hypothermia used?
to slow metabolism and prevent ischemic tissue
What is the risk of therapeutic hypothermia?
V fib or cardiac arrest
