Final answer:
Chronic pain can persist beyond the healing of injured tissue due to sterile inflammation and the actions of immune system components like macrophages. These chemical messengers maintain the sensation of pain by influencing pathways in the brain.
Step-by-step explanation:
Chronic pain often continues even after the injured tissue has healed, and it may involve sterile inflammation with participation from elements of the immune system like macrophages. These immune cells release chemical messengers that can perpetuate pain signals, leading to a persistent pain experience.
The coordinated response model illustrates how immune response chemicals can exacerbate or maintain chronic pain.
In the context of pain perception, nociception starts with sensory receptors, but the perception of pain is only commenced once the signal reaches the brain for processing, specifically at the thalamus and primary somatosensory cortex.
Nociceptive pathways also influence autonomic functions, such as the cardiovascular and neuroendocrine systems, linking pain with stress responses and potentially leading to increased pain sensitivity after stressful events.
Different treatments for pain, like relaxation therapies, analgesic medications, or even deep brain stimulation, target various aspects of these pathways to alleviate pain.
Treatment effectiveness depends on several factors, including the type of pain (neuropathic or inflammatory) and individual characteristics, such as psychological conditions and potentially sex-related responses to pain.