Final answer:
The statement that complex regional pain syndrome is fairly common is false; it is actually considered rare. Chemical messengers from immune cells can perpetuate chronic pain by sensitizing nociceptors. General anesthetics work systemically unlike local anesthetics, which work in a targeted area.
Step-by-step explanation:
The answer to the question about the prevalence of complex regional pain syndrome (CRPS) is false. CRPS is not considered to be fairly common; it is actually relatively rare. Chronic pain can indeed persist long after the initial injury that caused it has healed, and this condition is often associated with an abnormal immune response.
Chronic pain, like that seen in CRPS, can be maintained by the ongoing activity of immune cells such as macrophages. These immune cells release chemical messengers, including cytokines and growth factors, that contribute to inflammation and pain sensation. In refining our model of pain, we consider how these substances can sensitize nociceptors, the nerves responsible for detecting pain, thereby leading to a persistent pain state that is disproportionate to the initial injury.
Unlike local anesthetics, which simply block pain signals in a small, targeted area, general anesthetics are used during surgeries to induce unconsciousness and prevent the brain from processing any pain signals at all.