L7 - Pain Flashcards
(27 cards)
Define nociception
Neural process of encoding noxious stimuli
What is the name of the condition where you can’t feel pain?
Congenital insensitivity to pain (CIP)
What are the nociceptive fibres?
C and adelta
What Are the three main qualities of pain?
Therman
Mechano
Chemical
What are the main receptors for thermal pain?
Cold - TrpM8
Hot - TrpV1/V2
What are the specialized receptors for mechano pain?
Piezo channels
What are the specialized receptors for chemical pain?
TRPA1, ASICs, P2X3
What mutations can lead to CIP?
Mutations in Nav 1.7 and Nav 1.9
What are the inherited pain syndromes associated sith Nav 1.7 mutations?
Erythromelalgia - Burning hands and feet syndrome
Paroxysmal Extreme Pain Disorder (PEPD)
Small fibre neuropathy
What are the main neuropeptides released by nociceptors?
Substance P
Calcitonin gene related peptide (cGRP)
What does the release of substance P and CGRP cause?
Blood flow increases to the area
Production of: Histamine Bradykinin Serotonim Prostaglandin
What do eicosanoids do?
They are mediators of inflammation
List some eicosanoids and their functions
Leukotriene - chemotaxis, inflammation, anaphylaxis
Thromboxin - thrombocyte, aggregation, vasoconstriction
Prostaglandin - inflammation, vasodilation, vasoconstriction
Where can painkillers act to target peripheral sensitization?
NSAIDs inhibit Cox therefore inhibit prostaglandin production
Local anaesthetics target Nav 1.7, 1.8 and 1.9 channels
Where do A delta fibres project to in the spinal cord?
Peptidergic –> I
Non- peptidergic –> IV
Where do c fibres project to in. The spinak cord?
iI
What are the three mechanisms that lead to central sensitization?
Temporal and spatial summation
Ltp and homosynaptic facilitation
Heterosynaptic facilitation
In central sensitization what does homosynaptic facilitation do?
Enhances synaptic transmission
In central senstization what does heterosynaptic facilitation do?
Increase the size of the receptive field of the nociceptive afferent
In central sensitization what does NO do?
Increase the pre-synaptic response
What is allodynia?
Pain induced by a non-toxic stimuli due to heterosynaptic facilitTion by Abeta mechanoreceptors
What are the pain areas in the brain?
Front cingulate cortex Si Hypothalamis Formarion reticulus Insel Sii
What are the main pain phenomena?
Neuropathic pain
Neuralgia
Projected pain
What causes neuropathic pain?
Due to diseases of the peripheral nociceptive system
