Quiz 1 Flashcards
AB fibres
found in muscle spindle, 100m/s.
A-delta fibres
well localised, first pain, 40m/sec, Sharp, pricking pain
Type 1 pain
Pain from chemical or mechanical stimuli
Type 2 pain
Pain to thermal stimuli
C fibres
Slow second pain, 1-2m/s, dull burning quality
TRPV1 channels
Heat and chemical (approx 43 deg), capascin an acid sensiing (H+) V1 cars= hot
TRPM8
cold (+0), both noxious and innocuous, menthol M8 its cold
TRPA1
cold (-0deg)ad GI tract smooth muscle A for anus
ASIC 1
Git smooth muscle, cmustard, garlic, smoke
ASIC 2/3
cardiac and skeletal muscle, can be activated by anaerobic metabolism ASCIS is a sport shoe
naV channels
influence flow of sodium and therefore influence resting membrane potentials and thresholds.
NaV 1.7- in sympatetic and C fibres, upregulated in inflammatory conditions
Nav 1.8- c fibres, action potential in cold conditions
Nerve growth factor
released by macrohages and t lymphocytes
Tyrosine kinase is reeptor
1. binds directly to nociceptors
2. activates mast cells- degranulate- release histamie
3. increase sympathetic sprouting of nerves- increased receptive field
Interneurons
Excitatory glutamergic or inhibitory GABA/ glycine
Effects of intracellular Ca2+ on CS
- Increased Ca2+- activation of kinases- phosphorylate NMDA and AMPA- increased channel open times, quikcer Mg2+ remova, inreaed sensitivity
- Ca2+ activates Calmodulin (CaMK)- phosphorylates AMPA and makes modified AMPA receptors that are more efficient and open at loer activation levels
- PKC activation reduces effects of GABA and glycine and descending inhibition from PAG
Astrocytes
homestasis, neurotransmitter release and uptake, release NO, PGE2 and glutamate in inflammatory conditions
Microglia
like macrophages, accumulate in dorsal horn at injured nerve, neurotransmitter/cytokine release, activate in nerve injury, release SP, ATP, glutamate