Pain: peripheral mechanisms and central pathways Flashcards
what is the path of pain
Stimulus receptor action potential Spinal cord Ascends to brain sensory cortex
Features of myelinated neurones
Immediately
sharp
fast pain
fast conduction
Features of unmyelinated neurones
Slow
Dull
Delayed
Slow Conduction
What type of stimulus does mechanical supply
fast and dull
What type of stimulus does chemical supply
Dull
What type of stimulus thermal supply
Fast and dull
What are the nocioceptor pathways
Gracile and cuneatus fasciculs - A delta fibres Facial nerves ( trigeminal) - C fibres
What is meant by referred pain
Pain felt in a superficial area from a visceral organ
Difference in acute and chronic pain
Acute- physiological- nocioceptive/inflammatory
Chronic- pathological- neuropathic
Features of neuropathic pain
Lesion/disease in P/CNS
Burning/ticks
Hyperalgesia
Allodynia
When does peripheral sensation occur
Increased sensitivity of C and A delta fibres due to prostoglandin release
Increased voltage dependent Na+ channel
Increases threshold
What happens for central sensation
increase glutamate release
Increase expression of glutamate receptors
sprouting of A beta fibres to make new connections
Why does phantom limb pain occur
No signals
get signal from other parts of the body
