Pain Flashcards
what are the 2 types of pain?
nociceptive and neuropathic
define nociceptive pain.
pain that arises from actual or threatened damage to non-neural tissue and is due to the activation of noci receptors.
define neuropathic pain.
pain initiated or caused by a primary lesion or dysfunction of the nervous system.
what is the difference between an anaesthetic and an analgesic?
anaesthetic - complete removal of all sensations ie it sedates
analagesia - relief of pain
what are the 2 pain fibres?
C-fibres and A delta fibres
what are the difference between C-fibres and A delta fibres?
A-delta fibres = small diameter have a high threshold potential and respond to thermal and mechanical stimulation
C-fibres = smaller diameter, unmyelinated and slowest conduction. they have the highest threshold and detect selectively noxious stimuli.
what are the 2 neurotransmitters involved in pain?
substance P and glutamate
what is the melzack-wall pain gate?
non-noxious stimulant can cause the inhibition of a noxious stimulant
what is substance P?
a peptide neurotransmitter and neuromodulator only involved in conveying pain signals
where is pain processed?
sensorimotor cortex - area pain is coming from
anterior cingulate gyrus - emotional effect of pain
amygdala - emotional effect of pain
describe the action of opioids.
opioids bind presynaptic opiate receptors - prevents neurotransmitter to secreted from presynaptic membrane on afferent pain fibres - prevents transmission of pain signals to the brain
what is periaqueductal gray? and what is it for?
grey matter that surrounds the cerebral aqueduct and stimulation of it causes it to send 5HT to pain fibres causing inhibition of noxious signals resulting in profound analgesia
