Pain Flashcards
what is pain?
an unpleasant sensory and emotional experience associated with actual or potential tissues damage or described in such terms of such damage.
What are the 3 neuroanatomy of pain?
- Afferent pathways in the PNS travel along the spinal cord to the dorsal horn, then to higher centres in the CNS.
- Brainstem, midbrain, thalamus, and cerebral cortex all interpret pain.
- Efferent (descending) pathways descend from the CNS to the dorsal horn of the spinal cord, and reduce or eliminate pain signals.
What is transduction?
Electrical signals sent by the noicerecptors can be targeted by NSAIDs and gabapentinoids (gaba inhibitory neurotransmitter, less neurons firing)
What is transmission in terms of pain?
The electrical signal moving from the injury site to the spinal cord and brain can be the target for local anaesthetics and gabapentinoids.
What is a perception in terms of pain?
awareness of the pain by the somatosensory cortex of the brain targeted by opioids and NMDA (cedamine) receptor antagonists. Distraction techniques help with this.
what is the descending and local modulation?
Pain impulses may be enhanced or diminished either centrally ( descending pathways from the brain to the spinal cord) or the periphery are the target of modes such as epidual/ intrathecal, nerve blocks, and wounds infusions
How is pain perception transduced?
- mediated by A-delta( shooting and stinging pain and C-fibers on afferent nerve pathways are exposed to tissue damage due to inflammation, infection, or injury
- Neurotransmitters (inflammatory chemicals are released from the damaged cells)
- Medications work by blocking the production of neurotransmitters (ibuprofens stop prostglandins)
What is the difference between chronic and acute pain?
Acute = less than 6 mo.
Chronic = longer that 6 mo.
What is productive pain and non-productve pain?
Productive: correlated to tissue damage. serves a purpose as a warning of injury. Wanes as damage resolves, accompanied by sympathetic nervous system responses.
Non-productive: does not serve as a warning of injury. Cause of pain is difficult to identify. often accompanied by stress and depression.
What are the characteristics of A-delta fibers?
( Primary afferent fibers)
Sharp, stinging, prickling, localised, fast/ first pain sensations.
Stimulated by mechanical thermal stimuli
Located Fingertips, and hands
Large in Dia.
Myelinated
What are the characteristics of C-fibres?
(Primary afferent fibers)
Dull, ache, burning sensations, poorly localized, long-lasting. Slow/second pain sensations.
stimulated By mechanical, thermal, or chemical stimuli
Location in organs
Small in Dia.
Not myelinated
What are the characteristics of A-beta fibres?
Do not transmit pain.
Stimulated by touch and vibration.
Location is in the muscle fibers
Large in Dia.
myelinated
What are excitatory (or inflammatory) chemicals that activated the noicereceptors
Substance P
Bradykinin
prostaglandin
glutamate
Aspirate
Calcitonin gene-related peptide (CGRP)
nitric oxide
What are inhibitory chemicals that are activated by noicerecptors?
Dynorphin
Enkephalin
norepinephrine
seritonin
endorphins
gamma-aminobutyric acid (GABA)
What is somatic pain?
Connective tissue, muscles, or bone (torn Achilles tendon). Usually sharp, aching, throbbing, or gnawing
