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Hyperalgesia (/ ˌ h aɪ p ər æ l ˈ dʒ iː z i ə / or /-s i ə /; hyper from Greek ὑπέρ (huper) 'over' + -algesia from Greek ἄλγος (algos) 'pain') is an abnormally increased sensitivity to pain, which may be caused by damage to nociceptors or peripheral nerves and can cause hypersensitivity to stimulus.
In the case of hypoalgesia, a decreased response to pain would be very beneficial in a situation where an organism's life was at stake, since feeling pain would be a hindrance rather than a help. It has been well documented that fear does cause a decrease in pain response, [ 6 ] however much like the exercise induced hypoalgesia, the exact ...
In 1968, three years after the introduction of the gate control theory, Ronald Melzack concluded that pain is a multidimensional complex with numerous sensory, affective, cognitive, and evaluative components. Melzack's description has been adapted by the International Association for the Study of Pain in a contemporary definition of pain. [1]
Patients with such mutations are congenitally insensitive to pain and lack other neuropathies. There are three mutations in SCN9A: W897X, located in the P-loop of domain 2; I767X, located in the S2 segment of domain 2; and S459X, located in the linker region between domains 1 and 2. This results in a truncated non-functional protein.
' pain receptor ') is a sensory neuron that responds to damaging or potentially damaging stimuli by sending "possible threat" signals [1] [2] [3] to the spinal cord and the brain. The brain creates the sensation of pain to direct attention to the body part, so the threat can be mitigated; this process is called nociception .
Ao fibers synapse on laminae 1 and 5 while Ab synapses on 1, 3, 5, and C. C fibers exclusively synapse on lamina 2. [13] [14] The amygdala and hippocampus create and encode the memory and emotion due to pain stimuli. The hypothalamus signals for the release of hormones that make pain suppression more effective; some of these are sex hormones.
Aδ fibers are characterized by thin axons and thin myelin sheaths, and are either D-hair receptors or nociceptive neurons. Aδ fibers conduct at a rate of up to 25 m/s. D-hair receptors have large receptive fields and very low mechanical thresholds, and have been shown to be the most sensitive of known cutaneous mechanoreceptors.
Pain motivates organisms to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future. [2] Most pain resolves once the noxious stimulus is removed and the body has healed, but it may persist despite removal of the stimulus and apparent healing of the body. Sometimes pain ...