1. Inflammation is the body's response to infection, irritation, or injury, characterized by redness, swelling, heat, and pain. It involves the immune system and blood vessels. 2. Acute inflammation is a short-term response to recent injury or infection, marked by increased blood flow, blood vessel permeability, and migration of white blood cells. Chronic inflammation is a long-term response involving lymphocytes, macrophages, and fibrosis. 3. Inflammation can resolve, lead to abscess or fibrosis, and is mediated by chemical signals like histamine, bradykinin, prostaglandins, and cytokines. Different cell types and patterns characterize specific inflammatory diseases.