PAT 20 Week 4: Pain and Osteoarthritis
PAIN
Non-objective notes:
Analgesics: class of medications which relieve pain.
-Example: opioid analgesics are used to relieve moderate to severe pain.
Pain: “defined as an unpleasant sensory and emotional experience associated with either actual or
potential tissue damage”.
-Social environments can influence how a patient expresses pain. The origin, nature of pain, or access to
healthcare can hinder or prompt a patient to seek medical attention. For example: because of the
prevalence of heart and stroke in public health announcements, a patient experiencing chest pain is
more likely to seek emergency medical attention. In contrast, a patient experiencing depression may be
less likely to access help because of stigma attached to mental health.
Patient controlled analgesia (PCA): Patients self-medicate through pressing a button which activates a
PCA infusion pump. This method which is commonly used with fentanyl and morphine also reduces the
total opioid dose used.
-Opioid tolerance is a state of adaption in which continued exposure to a drug changes the drug
receptors causing a reduction in the drugs effect. Opioid tolerance can develop in as a little as one week.
-Longer-acting opioids such as methadone or extended-release oxycodone are usually better
choices than shorter-acting immediate-release drug products for these patients.
Allodynia: Sensation of pain from non-injurious stimuli to the skin
Hyperalgesia: Extreme sensitivity to pain
Analgesia: Absence of pain despite noxious stimuli
Two pain theories:
-Specificity theory: Describes pain as being a separate sensory modality which is evoked by the
activation of specific receptors which transmit information to pain centres of the forebrain.
-Gate control theory stems from this theory to include the presence of a neural gating
mechanism which determines which stimuli will be determined as painful. A
stimulus must surpass the pain threshold for pain to be experienced.
-Neuromatrix theory: By the same theorist who developed the gate control theory, this
theory further addresses the brains role in pain perception. Clinically this theory
is applied to chronic pain and phantom limb pain
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, -Pattern theory: Describes pain receptors as sharing pathways with other sensory stimuli. It
describes pain as being elicited through high frequency firing of receptors and other sensory as
being communication through low frequency firing.
1. Characterize the response of nociceptors to stimuli.
-Pain from a noxious stimulus stimulates sensory nerve fibres called nociceptors. Pain signals from
nociceptors travel through the spinal cord and brain to create pain sensation called nociception or
nociceptive pain.
-There are three receptors involved in pain:
-mu receptors in the dorsal horn of the spinal cord
-Pain perception and emotional well-being are linked to the number of mu receptors.
The number of mu receptors is controlled by the opioid receptor gene. When
the number of receptors is high pain sensitivity is diminished.
-kappa receptors
-delta receptors
2. Discuss the difference between the Aδ- and C-fiber neurons in the transmission of pain information.
See objective three “transmission”.
3. Trace the transmission of pain signals with reference to the neospinothalamic, paleospinothalamic
and reticulospinal pathways, including the role of chemical mediators and factors that modulate pain
transmission.
-Pain pathways are composed of first, second, and third order neurons. First order neurons detect
noxious stimuli, second order neuron process nociceptive information in the spinal cord, and third order
neurons deliver pain information to the brain.
Neospinothalamic tract: Associated with fast-conducting fibres that transmits sharp-fast pain (acute
pain). ***Delta A Fibres
-The neospinothalamic tract interconnects between the lateral thalamus and the
somatosensory cortex. For this reason we are able to identify the location and meaning of the
pain we are experiencing.
-Somatosensory cortex: Sensory area for touch.
Paleospinothalamic tract: Associated with slow-conducting fibres that transmit dull, aching pain
(chronic and visceral pain). ***C Fibres
This study source was downloaded by 100000898062787 from CourseHero.com on 09-30-2025 05:04:14 GMT -05:00
https://www.coursehero.com/file/251309824/PAT-20-Week-4-paindocx/
PAIN
Non-objective notes:
Analgesics: class of medications which relieve pain.
-Example: opioid analgesics are used to relieve moderate to severe pain.
Pain: “defined as an unpleasant sensory and emotional experience associated with either actual or
potential tissue damage”.
-Social environments can influence how a patient expresses pain. The origin, nature of pain, or access to
healthcare can hinder or prompt a patient to seek medical attention. For example: because of the
prevalence of heart and stroke in public health announcements, a patient experiencing chest pain is
more likely to seek emergency medical attention. In contrast, a patient experiencing depression may be
less likely to access help because of stigma attached to mental health.
Patient controlled analgesia (PCA): Patients self-medicate through pressing a button which activates a
PCA infusion pump. This method which is commonly used with fentanyl and morphine also reduces the
total opioid dose used.
-Opioid tolerance is a state of adaption in which continued exposure to a drug changes the drug
receptors causing a reduction in the drugs effect. Opioid tolerance can develop in as a little as one week.
-Longer-acting opioids such as methadone or extended-release oxycodone are usually better
choices than shorter-acting immediate-release drug products for these patients.
Allodynia: Sensation of pain from non-injurious stimuli to the skin
Hyperalgesia: Extreme sensitivity to pain
Analgesia: Absence of pain despite noxious stimuli
Two pain theories:
-Specificity theory: Describes pain as being a separate sensory modality which is evoked by the
activation of specific receptors which transmit information to pain centres of the forebrain.
-Gate control theory stems from this theory to include the presence of a neural gating
mechanism which determines which stimuli will be determined as painful. A
stimulus must surpass the pain threshold for pain to be experienced.
-Neuromatrix theory: By the same theorist who developed the gate control theory, this
theory further addresses the brains role in pain perception. Clinically this theory
is applied to chronic pain and phantom limb pain
This study source was downloaded by 100000898062787 from CourseHero.com on 09-30-2025 05:04:14 GMT -05:00
https://www.coursehero.com/file/251309824/PAT-20-Week-4-paindocx/
, -Pattern theory: Describes pain receptors as sharing pathways with other sensory stimuli. It
describes pain as being elicited through high frequency firing of receptors and other sensory as
being communication through low frequency firing.
1. Characterize the response of nociceptors to stimuli.
-Pain from a noxious stimulus stimulates sensory nerve fibres called nociceptors. Pain signals from
nociceptors travel through the spinal cord and brain to create pain sensation called nociception or
nociceptive pain.
-There are three receptors involved in pain:
-mu receptors in the dorsal horn of the spinal cord
-Pain perception and emotional well-being are linked to the number of mu receptors.
The number of mu receptors is controlled by the opioid receptor gene. When
the number of receptors is high pain sensitivity is diminished.
-kappa receptors
-delta receptors
2. Discuss the difference between the Aδ- and C-fiber neurons in the transmission of pain information.
See objective three “transmission”.
3. Trace the transmission of pain signals with reference to the neospinothalamic, paleospinothalamic
and reticulospinal pathways, including the role of chemical mediators and factors that modulate pain
transmission.
-Pain pathways are composed of first, second, and third order neurons. First order neurons detect
noxious stimuli, second order neuron process nociceptive information in the spinal cord, and third order
neurons deliver pain information to the brain.
Neospinothalamic tract: Associated with fast-conducting fibres that transmits sharp-fast pain (acute
pain). ***Delta A Fibres
-The neospinothalamic tract interconnects between the lateral thalamus and the
somatosensory cortex. For this reason we are able to identify the location and meaning of the
pain we are experiencing.
-Somatosensory cortex: Sensory area for touch.
Paleospinothalamic tract: Associated with slow-conducting fibres that transmit dull, aching pain
(chronic and visceral pain). ***C Fibres
This study source was downloaded by 100000898062787 from CourseHero.com on 09-30-2025 05:04:14 GMT -05:00
https://www.coursehero.com/file/251309824/PAT-20-Week-4-paindocx/
