Immunity Ch. 11.1-6 Microbiology

Immunology Study of how the body protects against and responds to pathogens or disease to keep you healthy.

Overview of Immune System Protects against disease (pathogens) Three Levels of Defense Physical & Chemical barriers- skin, mucous, flora Innate-immediate non-specific, inflammation, phagocytes Adaptive (acquired)-slower, develops over time, specific, antibodies

11.1 Organs of the Immune System Thymus Spleen Tonsils Bone marrow

11.1 Tissues of the Immune System Lymph Vessels Lymph nodes Adenoids Skin Liver

11.1 Cells of the Immune System Hematopoietic stem cells Innate Leukocytes (white blood cells) Phagocytes Macrophages Neutrophils Dendritic cells Mast cells Eosinophils Basophils Natural killer (NK) cells

11.1 Cells of the Immune System Adaptive Leukocytes (Lymphocytes) B cells-bone marrow T cells-thymus

1.1 Human-Microbial Interactions Human Microbiome Project Flora-Mutualistic both benefit or Commensal-one benefits, other is not harmed Skin-protection from pathogens Gut-vitamins, hormones, protection, remove toxins & immune system development Relatively few microbes are pathogenic

11.2 Innate Immune Response Natural Killer (NK) cells Recognize infected or tumorigenic cells and kill them. Major Histocompatibility Complex (MHC) I molecules Release perforin which makes the cells self-destruct (apoptosis)

11.2 Physical & Chemical Barriers Skin Cilia-lungs Tears Mucus Sweat pH-stomach, vagina

11.2 The Complement System Around 20 soluble proteins help destroy extracellular microorganisms Produced by the liver & macrophages Proteins bind to invaders (non-self) (opsonization) to identify them for destruction.

11.2 Pathogen Recognition Pathogen-Associated molecular Patterns (PAMPs) Pattern-Recognition Receptors (PRRs) Cytokines released, trigger inflammation Interferons warn nearby cells, apoptosis Interleukins help leukocytes Phagocytosis

11.3 Phagocytosis Engulfment of foreign material in the body by a specialized cell Macrophages Dendritic cells Neutrophils

11.3 Antigen-presenting B & T cells Recognizes antigens derived from pathogens. If you have a secondary infection from the same or a similar pathogen, memory B and T cells will give you immunity. This natural process of creating immunity is enhanced artificially by the use of vaccines.

11.4 The Complement System Three Biochemical Pathways: Classical Alternative Lectin Four Functions: Opsonization Chemotaxis Lysis Clumping

11.4 Innate Defenders Toll-Like Receptors (TLRs) recognize molecules associated with pathogens Iron-Binding Proteins remove iron from blood to limit pathogenic growth. Antimicrobial peptides kill bacteria, found on skin and in blood

11.5 Adaptive Immune Response Humoral Response Defends against pathogens using antibodies against pathogen- specific antigens. B & T cells Differentiation Hematopoiesis (stem cells)

11.6 Antigens & Antibodies Immunodeficiency Failure to respond, HIV/AIDS Antibody Functions Neutralization Opsonization Complement activation