PAIN AND NOCICEPTION Flashcards
what is pain?
an unpleasant sensory and emotional experience associated with actual or potential tissue damage
what is nociception?
the neural processes of detecting, encoding and processing noxious stimuli
why is pain good?
it is an early cue to help protect our bodies from serious harm
it teaches us to avoid harmful situations
it forces us to rest an injured part of the body to allow tissue repair
it makes us toss and turn in sleep to prevent bedsores or skeletal strain
why is pain bad?
sometimes it serves no useful function e.g. in chronic pain
pain can persist even when tissues have healed
what is acute pain?
pain that resolves when the injury heals and is expected to end in days or weeks, it forces rest and avoidance of further harm. It is adequately treatable
what is chronic pain?
pain persists and duration is long and unpredictable. it has no biological function and rest does not improve pain. it is poorly treatable.
what is visceral pain?
pain from organs of the thorax and abdominal cavity. it is a dull aching pain or a vague burning that can be poorly located
what is somatic pain?
pain from skin (superficial) or muscles, joints, deep skin layers and connective tissue (deep)
what lasts longer superficial or deep somatic pain? what do they both feel like?
deep pain lasts longer
superficial pain is a pinching whilst deep pain is an aching, burning or itching pain
what are nociceptors?
free nerve endings found in most body tissues other than the brain that respond specifically to noxious stimuli
what is a noxious stimulus?
one that is actually or potentially a tissue-damaging event
what are the 5 types of nociceptors?
thermal mechanical chemical polynomial sleeping/silent
what are thermal nociceptors activated by?
extreme temperatre
what are mechanical nociceptors activated by?
excess pressure or mechanical deformation
what are chemical nociceptors activated by?
chemical stimulants
what are polymodal nociceptors activated by?
extreme temperature, excess pressure, mechanical deformation, chemical stimulants
what are sleeping nociceptors activated by?
inflammation
what are the 4 types of primary afferents?
A-alpha, A-beta, A-delta, C
which of the 4 primary afferents have large diameters and are myelinated?
what does this mean?
A-alpha and A-beta
they are rapidly conducting
what do A-alpha primary afferent carry?
information related to proprioception
what do A-beta primary afferent carry?
information related to touch