Term
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Definition
| unmyelinated nociceptive neuron that responds to mechanical thermal and chemical stimulation |
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Term
| silent or sleepy nociceptors |
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Definition
| normally unresponsive to noxious stimuli but become active when the tissue they innervate becomes inflamed |
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Term
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Definition
| initial sensation of sharp pain, A delta afferents |
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Term
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Definition
| comes a second or two after the painful event, diffuse, poorly localized, long lasting, causes more suffering, C fibers |
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Term
| substances that cause inflammation |
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Definition
| potassium, peptides (bradykinin and substance P), serotonin, histamine, prostaglandins --> cause leaking of fluid from vessles, dilation of blood vessles, increased activity in nociceptors |
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Term
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Definition
| rubor (red) tumor (swelling) dolor (pain) calor (heat) |
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Term
| zone of primary hyperalgesia |
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Definition
| area around injured site that has a lowered pain threshold because of activity of sleepy nociceptors |
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Term
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Definition
| when skin temp rises above 45 C the cold receptors become active again too |
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Term
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Definition
| when certain internal organs are damaged, the pain is often felt somewhere else |
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Term
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Definition
| other pain - normally innocuous stimuli cuase pain, or when pain occurs away from area actually stimulated |
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Term
| nociceptor-specific neurons |
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Definition
| actiavated only by noxious stimulation |
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Term
| wide dynamic range neurons |
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Definition
| respond to both noxious and innocuous input |
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Term
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Definition
| pain system and crude touch. fibers are in the anterolateral column of the spinal cord. go to reticular formation and other components of the brain stem, some to thalamus |
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Term
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Definition
| burning pain associated with contact with very cold objects can be reproduced by touching the skin with interlacing ars that were alternately hot and cold. shows pain can be evoked by a pattern of non-noxious stimuli |
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Term
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Definition
| persistant pain in absence of any noxious stimuli |
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Term
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Definition
| lesions of the thalamus associated with unbearable pain in a part of the body that is, by sensory testing, completely ansthetic |
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Term
| gate control theory of Melzack and Wall |
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Definition
| explanation for counter-irritation effect - rub area around injury relieves the pain to some degree. proposed that neural activity in large diameter cutaneous fibers, inhibited pain receptors from passing info to brain |
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Term
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Definition
| control point in dorsal horn where pain impulses pass through |
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Term
| periventricular gray (PVG) periaqueductal gray (PAG) |
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Definition
| emotions and other psychological factors provoke activity in this part of the brain, which in turn activate the raphe nuclei of the medulla |
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Term
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Definition
| activated by PVG and PAG of upper brainstem and diencephalon - project then to dorsal horn via dorsolateral columns |
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