Pain and Temperature Flashcards
(91 cards)
Define Pain
- An unpleasant sensory and emotional experience
- Associated with actual or potential tissue damage.
Specificity Theory
- Low and high threshold receptors in specific pathway for pain that is independent of other senses
- Intensity of pain related to amount of tissue damage
Patterning Theory
- Somatic receptors of variable sensitivity
- Different sense organs have different levels of responsiveness to stimuli
Gate Control Theory
- Pain modulated by gate in substantia gelatinosa
- Large myelinated A-delta fibers and small un-myelinated C-fibers respond to painful stimuli like mechanical, thermal, and chemical signals that open the “gate”.
- Stimuli from nociceptive transmissions, such as touching vibration are larger A-Beta fibers that close the gate.
Neuromatrix Theory
- Sensory inputs to the brain produce patterns of pain
- Illustrates Plasticity - the adaptable change in structure and function of the brain networks over time.
- Explains phantom limb pain
3 types of Opioid receptors? What are there endogenous ligands?
1) Mu (μ) – Contributes most of the signs of opioid administration - Endorphins
2) Delta (δ) - Enkephalins
3) Kappa (K) - Dynorphins
Since each Opioid receptor is a G-protein linked receptor, explain what happens when an agonist binds the receptor?
- Binding to an Opioid receptor
- G-protein (Gi) inactivates adenylate cyclase
- Decrease in cAMP and neuronal function.
3 locations of Opioid Receptors?
1) Brain
2) Spinal Cord
3) Peripheral
What are the effects when the following opioid sub-receptors are banded:
1) Mu-1
2) Mu-2
3) Mu-3
1) Mu-1 - Bradycardia and analgesia (spinal and supraspinal)
2) Mu-2 - Analgesia (spinal only), respiratory depression, constipation, physical dependence
3) Mu-3 - Immune suppression
Edinger-Westphal Nucleus?
Opioid stimulation causes this nucleus to constrict the pupils (miosis).
Organize the following opioids from most potent to least potent:
1) Sufentanil
2) Fentanyl
3) Dilaudud
4) Morphine
5) Meperidine
6) Remifentanil
7) Alfentanil
Sufentanil > Fentanyl > Remifentanil > Alfentanil > Hydromorphone > Morphine > Meperidine
(T/F?) Although all the opioids cause miosis (pupil constriction) Meperidine will not cause this?
True (Meperidine causes mydriasis and increased HR)
Toxidrome symptoms?
CPR-3H
1) Coma
2) Pinpoint Pupils
3) Respiratory Depression
4) Hypotension
5) Hypothermia
6) Hyporeflexia
PTs with who develop tolerance to the effects of opioids will never develop tolerance to which 2 opioid effects?
Miosis and constipation
What are the early and late symptoms of opioid withdrawal?
1) Early Symptoms - Diaphoresis, insomnia and restlessness
2) Late Symptoms - Abd cramping, nausea and vomitting
What are the onset, peak and duration of the following opioids’ withdrawal:
1) Fentanyl and Meperidine -
2) Morphine and Heroin
3) Methadone
1) Fentanyl and Meperidine - Onset 2-6hrs, peak 6-12 hrs, duration 4-5 days
2) Morphine and Heroin - Onset 6-18hrs, peak 36-72 hrs, duration 7-10 days
3) Methadone - Onset 24-48hrs, peak 3-21 days, duration 6-7 weeks
Describe the characteristics of the following peripheral nerve fibers:
1) A-beta
2) A-delta
3) C-fiber dorsal root
1) A-beta - Heavily myelinated, used for touch and pressure, 5-12 micrometer diameter
2) A-delta - Medium myelinated, used for fast pain, touch and pressure, 2-5 micrometer diameter
3) C-fiber dorsal root - No myelination, used for slow pain, touch and pressure, .4-1.2 micrometer diameter
What are the 3 system necessary for pain?
1) Afferent Pathway - Begins in the PNS, travels to the spinal gate in the dorsal horn.
2) Interpretive Centers - Located in the brainstem, midbrain, diencephalon, and cerebral cortex.
3) Efferent Pathway - Modulates pain
What are the four elements of Pain Processing?
1) Transduction
2) Transmission
3) Modulation
4) Perception
What happens during the Transduction step of pain processing?
- Tissue gets damaged by exposure to chemical, mechanical, thermal, or noxious stimuli
- Stimuli is converted to an action potential.
What happens during the conduction step of pain processing?
-Pain signals from A-delta and C-fibers in dorsal horn excite or inhibit signals to 2nd order neurons.
What happens during the Transmission step of the pain process?
If pain signals from A-delta and C-fibers excite 2nd order neurons, signal proceeds to the thalamus, brainstem and cortex.
What happens during the Perception step of the pain process?
-Cognitive evaluative system makes you consciously aware of the pain.
What happens during the Modulation step of the pain process?
Pain is suppressed or facilitated