Test 3: 37 pain Flashcards
nociception
the sensory nervous system’s response to a harmful or potentially
harmful stimuli
pain vs nociception
Nociception– the sensory nervous system’s response to a harmful or potentially harmful stimuli
Pain – nociception + perception (needs consciousness)
acute pain
last less than 3 – 6 months, and/or is directly related to tissue damage. Short duration and gradually resolves as injured tissues heal.
chronic pain
extends beyond the expected period of healing (long duration), is not related to resolving injury, has no useful purpose, and is refractory to treatment.
abnormally increase in sensitivity to pain (“what hurts, now hurts a lot more”)
Hyperalgesia
triggering of a pain response from a stimuli that do not normally provoke pain (“what should not hurt, now hurts”)
allodynia
tranduction of pain
change of noxious stimuli into electrical impulse
transmission of pain
- Propagation of impulse through the nervous system
- A-delta fibers – myelinated, fast speed, sharp pain
- C fibers – unmyelinated, slow speed, longer-lasting, dull, diffuse pain
what kind of pain fibers for dull, diffuse pain
C fibers: unmyelinated, slow speed, longer-lasting, dull, diffuse pain
what find of pain fibers for sharp pain
A-delta fibers: myelinated, fast speeds, sharp pain
how does modulation of pain work
in spinal cord- will change the pain tranmission
activate descending analgesic systems: opioids, serotonin, NE
perception of pain is by
Integration of thalamocortical, reticular, and limbic function to produce final conscious subjective and emotional experience
3 neuron pain pathway simply is
First Order
* Originates in the periphery and projects to the spinal cord- primary afferent fiber
Second order
* Ascends to the spinal cord
Third order
* Projects into the cerebral cortex and other supraspinal structures
how do TRP work
Transient receptor potential (TRP) vanilloid / capsaicin (TRPV1)
- TRP are activated and allow calcium influx into the 1st order neuron, activating an action potential
- Acute pain – receptor turns off as soon as the stimulus is gone
- Chronic pain – receptors don’t turn off, and activating substances persist : Substance P, Calcitonin gene-related peptide, Potassium ions and Inflammatory mediators
lamina V contain — neurons that are able to respond to both — and —
wide dynamic range
noxious and non noxious stilumi
can be involed in wind up pain and the development of chronic pain