Innate & Adaptive Immunity + Inflammation
Walden University – Advanced Pathophysiology
High-Yield Notes | NCLEX-Style Questions Included
Core Concepts in Immunity
1. Innate Immunity (Nonspecific Defense)
• First line: Skin, mucous membranes, tears, saliva
• Second line: Inflammation, fever, phagocytes (neutrophils/macrophages)
• Key cells: Natural Killer (NK) cells, dendritic cells, mast cells
• Fast acting, no memory
2. Adaptive Immunity (Specific Defense)
• Slower to activate, but specific and has memory
• Humoral immunity: B cells → antibodies (IgG, IgA, IgM, IgE, IgD)
• Cell-mediated immunity: T cells (CD4 = helper, CD8 = cytotoxic)
• Requires antigen presentation by MHC (I and II)
3. Inflammation
• Cardinal signs: Redness, heat, swelling, pain, loss of function
• Chemical mediators: Histamine, prostaglandins, cytokines
• Acute inflammation = short-lived (e.g., injury)
• Chronic inflammation = prolonged, may lead to tissue damage (e.g., RA)
4. Hypersensitivity Reactions
Type Mechanism Example
I IgE-mediated (immediate) Anaphylaxis, asthma
II Cytotoxic (IgG/IgM) Hemolytic anemia, transfusion rxn
III Immune complex Lupus, RA