Pain experience 2 Flashcards
what type of nerves transmit signals from the periphery to the trigeminal nuclei?
primary afferent
what type of nerves transmit signals from the trigeminal nuclei to the thalamus?
2nd order neurone
what type of nerves transmit signals from the thalamus to the cerebral cortex?
cortical projection
list the locations in order of the nociceptive pathway from a stimulus in the periphery
detection in periphery
primary afferent nerves
pons trigeminal tract
1st synapse at trigeminal nuclei
2nd order neurone
2nd synapse at thalamus
cortical projection
cerebral cortex
which trigeminal nuclei are linked to pain?
caudalis
oralis - specifically tooth pain
interactions between pathways
what is divergence?
primary afferent nerve synapses with many 2nd order nerves
interactions between pathways
what is convergence?
Many primary afferent nerves synapse to one 2nd order nerve.
This allows summation and spatial inaccuracies
Multiple teeth are supplied by one axon so difficult to locate dental pain
interactions between pathways
what is discrete pain
pain coming from a precise location
interaction between pathways
what is hyperalgesia?
increased response to a noxious/nociceptive stimulus -> more pain experienced as other nerves are sensitised
interactions between pathways
what is radiating pain?
pain feels like its coming from a larger area
interactions between pathways
what is referred pain?
pain in another area not the site of stimulus -> maxillary sinus as tooth pain
modulation/modification of the signal
what is the gate control theory?
inhibitory interneurones activated by other receptors e.g. mechanoreceptors can reduce the depolarisation in the 1st synapse reducing the pain.
what are segmental controls/inputs?
Inputs from the same part of the body e.g. rub
what are descending controls?
emotions can control pain experience
what is diffuse noxious inhibitory controls?
pain cancels pain
