Topic 5: Pain1: Intro Flashcards
Define pain according to the international Association for the study of pain
And unpleasant sensory and emotional experience associated with actual or potential tissue damage
Can pain exist without tissue damage and without detection by current diagnostic methods?
Should it be excepted as pain?
Strong evidence suggest YES pain can exist without tissue damage.
YES, If people report pain in the same way as pain caused by tissue damage, it should be accepted as pain.
The bio psycho social model of pain
Pain does not consist simply of biological factors but also psychological and social factors.
i.e.: thoughts, emotions and behaviours such as psychological distress, fear/avoidance believes, current coping methods and social economical, social environmental, and cultural factors contribute
Acute pain
- sudden onset usually sharp in quality
- warning of disease or threat to the body
- mostly does not last longer than six months, and disappears when underlying cause of pain has been treated or healed.
Can unrelieved acute pain lead to chronic pain?
Yyyyyeah
Chronic pain
- pain persists despite the fact the injury has healed
- pain signals remain active in the nervous system for weeks, months, or years
Physical effects of chronic pain
Tense muscles
Limited mobility
Lack of energy
Changes in appetite
Emotional effects of chronic pain
Depression
Anger
Anxiety
Fear of re-injury
How is pain classified?
Adaptive or maladaptive
Adaptive pain
Serves as an early warning system of potential injury from damaging stimulus
Maladaptive pain
Persists and becomes even more intense after healing apparently is complete
Pains adaptive role in healing:
Forces us to rest and reduce the likelihood of further injury
What is nociceptive pain?
AKA: acute pain
- detection of potentially tissue damaging noxious stimuli
- Early warning system to detect and minimize contact with damaging or noxious stimuli
When nociceptive pain is engaged what does it overrule? and what reflex does it initiate?
Over rules most other neural functions
Initiates withdrawal reflex, demand immediate attention in action
What can congenital insensitivity to pain result in?
Self-mutilation
Bone fractures
Multiple scars
Joint deformities
Amputations and early death
Peripheral neuropathy leads to_____________.
A sensory denervation of joints.
Example: Charcot arthropathy
What is Charcot Arthropathy?
Charcot foot occurs in patients with peripheral neuropathy resulting from the adverse conditions including diabetes, mellitus, leprosy, syphilis, poliomyelitis, chronic alcoholism.
Inflammatory pain
Caused by activation of the immune system by tissue injury or infection.
Inflammatory pain is________ and ________.
Adaptive and protective
After tissue damage inflammatory pain heightens ___________.
Pain sensitivity
How does inflammatory pain assist in healing?
Discourages contact and movement
Pathological pain
Maladaptive pain/. Pain that is not protective.
Pathological pain is a result of_______.
Abnormal functioning of the nervous system
pathological pain a disease state of the_______.
Nervous system
(It is not a symptom of some disorder).
Pathological pain can be evoked when there is no_________, ________.
Damage to the nervous system (Neuropathic pain),
No inflammation
Examples of conditions that can evoke maladaptive pain:
Fibromyalgia,
irritable bowel syndrome,
tension type headache, temporomandibular joint disease,
interstitial cystitis
And other syndromes in which there exists substantial pain but no noxious stimuli and no or minimal peripheral inflammatory pathology
Pathological pain is a consequence of_____.
Amplified sensory signals in the CNS (Allodynia)
Neuropathic pain can be from and coexist with_____.
Nociceptive pain
Pain modulation regulated by ______ and __________ circuits in the CNS
Excitatory and inhibitory
The CNS can either diminished or exaggerate pain depending on…
Mood, cognitive function, and memories.
Genetic and epigenetic component of pain modulation
Susceptibility, hypersensitivity, and conversion from acute to chronic pain
What is epigenetics?
The study of changes in organisms caused by modification of gene expression rather than alteration of genetic code itself.
Phenotype
How genetic and environmental influences come together to create an organism’s physical appearance and behaviour.
Genotype
Genetic code
Epigenetic change can be influenced by…
Age, the environment and lifestyle, and disease state.
Three neuron tract of pain
NEO SPINOTHALAMIC TRACT:
First order in the dorsal horn,
second order in the Thalamus,
third order in the primal somatosensory cortex
Multi Neuron tract of pain
PALEOSPINOTHALAMIC TRACT
It goes through the limbic system and gives affective (emotional) component
Axoplasmic transport
Aka axonal transport
Is??
As cellular process responsible for movement of mitochondria, lipids, synaptic vessels, proteins, and organelles to and from a multi polar neurons cell body through the cytoplasm of its axon.
(Anterograde and retrograde)
What is necessary for cell division and for axonal transport?
Microtubules
Pic: pg 7 of 17
Neurotransmitters released by the peripheral axon of the C fibre
substance P and glutamate
Mast cells
Immune cells release histamine
Released by mast cells activated by substance P
Histamine
Small protein hormones that have many normal cell functions and regulates cells involved in nonspecific and immune responses
Cytokines
Released by damage cells that intensify and prolong the pain associated with inflammation
Prostaglandins
A group of organic compounds found in high concentrations in meat products, especially internal organs such as liver and kidney, in general, plant-based diet are low in these
Purines
Extremely potent mediators of immediate hypersensitivity reaction’s and inflammation, producing smooth muscle contraction especially bronchoconstriction, increase vasculature probability, and migration of leucocytes two areas of inflammation
Leukotrines
Algogenic substances released into the ECF when cells are injured or destroyed, affecting C fibres in very low concentrations:
Substance P and glutamate Histamine Cytokines Prostaglandins Purines Leukotrines
Central sensation or plasticity
Changes in levels of neurotransmitters and APs that occur in the CNS in response to repeated nerve stimulation
Glutamate receptors
NMDA (N-methyl-D-aspartate)
Glutamate acts in the spinal cord and in brain sites to amplify_________.
Sensory input from the periphery.
NMDA receives glutamate
Increasing response and expansion of receptive fields to repeated input from C fibres
“Windup”
Repeated or prolonged application of noxious stimuli and non-noxious stimuli result in ….
Enhanced CNS excitability and sensation.
