what are the two phases of pain?
- dull, throbbing pain
- sharp, instant pain
what receptors are for pain perception?
nociceptors
what kind of pain fibres are A-delta?
- sharp and fast
what kind of pain fibres are c-fibres?
- dull and slow
what kind of stimulation does a-delta fibres respond to?
mechanical stimulation
what kind of pain stimulation does c-fibres respond to?
mechanical and chemical
which lamina does A-delta fibres synapse with?
1 and 5
which lamina does c-fibres synapse with?
1 and 2
what is periaqueductal grey matter?
- primary control centre fo descending pain modulation
what kind of cells are in the periaqueductal grey matter?
enkephalin producing cells that suppress pain
what is the locus coeruleus?
- nucleus in the pons of brainstem
what does locus coeruleus respond to?
stress and panic
what does locus coeruleus synthesize?
norepinephrine
where is raphe nucleus found?
brain stem
what is the function fo raphe nucleus?
release serotonin to the rest of the brain
where does the projections of raphe nucleus terminate?
dorsal horn of spinal grey matter
what does the projections of raphe nucleus do?
regulate release of enkephalins
what is peripheral senitisation?
- lower threshold of pain
- nociceptors become sensitised –> more sensitive
- trigger pain response from stimuli which normall do not provoke pain
what is central senitisation?
- sensitisation within soinal cord and brain
where does central sensitisation occur?
- spinal cord
- thalamus
- amygdala
- anterior cingulate cortex
what does AMPA do?
allow sodium into the cell
what does NMDA do?
less distinctice therefore they let any positive charge across membrane
what does sensitisation mean in terms of receptors?
more receptors therefore lower stimulus can trigger pain pathway
what is the gated theory of pain?
- non-painful stimulus closes the gates to painful stimulus
