Final answer:
Chronic pain in fibromyalgia involves changes in pain transmission in the spinal cord.
Step-by-step explanation:
Chronic pain in fibromyalgia involves changes in pain transmission in the spinal cord. It is not caused by autoimmune destruction of muscle tissue, muscle inflammation, or nerve inflammation. Fibromyalgia is a condition characterized by widespread musculoskeletal pain, fatigue, and tenderness in specific areas of the body.