INFLAMMATORY RESPONSE - A part of innate immunity. Inflammation occurs when tissues are injured by viruses, bacteria, trauma, chemicals, heat, cold, or any other harmful stimulus. Chemicals including bradykinin, histamine, serotonin, and others are released by specialized cells. These chemicals attract tissue macrophages and white blood cells to localize in an area to engulf (phagocytize) and destroy foreign substances. A byproduct of this activity is the formation of pus--a combination of white blood cells, bacteria, and foreign debris. The chemical mediators released during the inflammatory response give rise to the typical findings associated with inflammation.