Pain 1 Flashcards
what is the dura mater?
tough outer layer of skull
what is arachnoid layer?
middle spider wed layer of skull
what is Pia mater?
soft inside of skull
what are the 4 stages of pain perception?
transduction, transmission, perception, modulation
what is transmission of pain?
pain impulses from site of tissue damage along nerve fibres in dorsal roots to the brain
what is perception of pain?
the pain signal reaching the sensory cortex in the brain
what is modulation of pain signal?
relaying of motor signal in response via the ventral route
what do nociceptors respond to?
to a noxious stimulus or one that would become noxious if prolonged
what is a noxious stimulus?
one that is damaging to tissues
what are the types of noxious stimulus?
chemical, thermal or mechanical
what is stimulated by chemical triggers?
polymodal nociceptors on C fibres
what is stimulated by thermal triggers?
high threshold mechanothermal receptors on A-delta neurones and polymodal receptors
what is stimulated by mechanical triggers?
polymodal, mechanothermal and high threshold mechanoreceptors on A delta neurones
what is the process of non-noxious stimuli?
activate low threshold receptors, sends signals via afferent pathways to CNS and processed as innocuous
what is the process of a noxious stimuli?
activates low and high threshold receptors and nociceptors which activates specific pathway. and processed as physiological pain
what is the spinothalamic tract?
spine to the thalamus
what is the spinoreticular tract?
connects spine to reticular formation
what happens when the signal reaches the thalamus?
it acts as a sensory relay centre and causes further connections
where are nerve impulses transmitted past the thalamus?
to hypothalamus, limbic system and somatosensory cortex
what type of response is hypothalamus responsible for?
stress response
what type of response is the limbic system responsible for?
emotional response
what is the somatosensory cortex response used for?
to localise pain
what are the features of C fibres?
small and unmyelinated
what are the features of A fibres?
largest fibres, myelinated, are alpha/beta/gamma
how is fast pain caused?
stimulated of high threshold thermomechanical nociceptors
what fibres conduct fast pain?
A delta fibres
how is slow pain caused?
activation of high threshold polymodal pain receptors
what type of fibres conduct slow pain?
C fibres
