Pain Medications and How They Work

摘要

Pain is a subjective experience with two complementary but unpleasant aspects: one is a localized sensation on a particular body part or region, the other is a mechanical quality of varying severity commonly associated with behaviors directed at relieving or terminating the experience. Depending on the species and the neuroanatomy, this also can involve an emotional response. Pain begins with specific receptors. Differing species will have varying numbers of receptors based on their evolutionary development and central nervous system (CNS) physiology. Receptors are on nerve endings present in most body tissues that respond, in a normal situation, to noxious stimuli and evoke a response to things that might be damaging or potentially damaging to theorganism. There are other forms of pain that do not have an evolutionary basis (known as chronic or neuropathic pain, with several different etiologies).