pain mechanism 1 Flashcards
what is pain?
unpleasant phenomenon uniquely experienced by each individual
three systems that produce pain?
- sensory
- motivational
- cognitive
what does the sensory system do?
a discriminative system that processes info about strength, intensity, quality and spatial aspects of pain.
what does the motivational system do?
an affective system that determines the persons approach-avoidance behaviour
what does the cognitive system do?
it evaluates the individuals behaviour concerning their experience of pain.
what is somatogenic pain?
pain with a localised cause.
two types of somatogenic pain?
- nociceptive
2. neuropathic
what is psychogenic pain?
pain where there’s no physical cause - more to do with CNS process is disturbed
what is acute pain?
a protective mechanism that alerts the individual to a condition or experience that is immediately harmful to the body
what nervous system is associated with the perception of pain?
autonomic nervous system
what is chronic pain?
persistent or intermittent usually defined as lasting at least 3-6 months. (continues when it should not)
what decreases pain tolerance?
- with repeated exposure to pain,
- by fatigue, anger, boredom, apprehension
- sleep deprivation.
what increases pain tolerance?
- by alcohol consumption,
- medication, hypnosis,
- warmth, distracting activities
- strong beliefs or faith.
what effect does age have on pain threshold?
threshold increases with age
what is the gate theory of pain?
signals received and sent to the spinal cord (the gate), which decides whether to amplify the pain or attenuate it.
what type of afferent nociceptors do bone and visceral tissues have?
peptidergic C afferents
where are nociceptors localised to?
muscle, skin and viscera
which are more and least myelinated out of A-beta, A-delta and C fibres?
A-beta = most myelinated (thick myelin sheath) C = least myelinated (no myelin sheath) A-delta = thin myelin sheath
what are A-delta fibres useful for?
crucial for the fast signalling of injury
what fibres are 1st and 2nd pain detected by?
1st pain is mainly detected by A-beta and delta whilst 2nd pain is detected by C fibres.
what are TRP (VR) classes of nociceptors for?
thermal sensitivity
what are TREK classes of nociceptors for?
co-expressed with TRP and K+ channels for heat sensitivity. Activity is reduced by heat
what are ASICS and DRASICS classes of nociceptors for?
detect H+ and are cation selective. DRASICS also detect mechanical stimuli.
what are MDEG classes of nociceptors for?
sensitive to sodium channels
