MCS Cycle 6 // SEM 2 - Study Pack

What is chemotaxis? Movement of an organism in response to a chemical stimulus What is normal flora? Microbes that live on and in body without causing apparent harm (the bodies norm) What are lymphocytes? white blood cells What are B cells? B-lymphocytes; they release antibodies into blood. What are T cells? A lymphocyte of a type produced or processed by the thymus gland and actively participating in the immune response. What are leukocytes? white blood cells All 5 types of white blood cell? Mast cell, Macrophage, Neutrophil, Eosinophil, Basophil * Dendritic cells, T + B Cells also count What is a B lymphocyte (B cell) precur- Plasma cell (basically a developed B cell, sor too? that can not secrete antibodies) 3 types of cell that are APC's? (Antigen Presenting Cell's) Dendritic Cells Macrophages B-cells Humoral immunity is one half of adaptive immunity, which protects the extracellular space (fluid that surrounds cells), what type of cell does it use? Activated B cells (plasma cells) Two types of T cells CD4 - Helper T cells (activate macrophages) CD8 - Cytotoxic T cells (kill infected cells / cancer cells) What do CD8 T cells secrete? Perforin - delivers contents of granules into cytoplasm of target cell Granzymes - induce apoptosis in cytoplasm of target cell Granulysin - kill intracellular bacteria 1/6 Big difference between B cells and T cells? T cells - Cell mediated immunity (kill cells) B cells - Antibody mediated immunity (make antibodies) What is phagocytosis? Cell eating 4 ways antibodies can work? - Labels for identification of antigens (so they can be phagocytized) - Anti toxins (they block toxins) - Attach to bacteria flagella, making them less motile, allowing them to be captured and engulfed easier - Cause agglunation, meaning bacteria clump and don't spread What are the four types of defensive barriers for innate immunity? Anatomic Physiologic Phagocytic Inflammatory What comes under the Anatomic barriers? Skin Sebaceous glands Mucous membranes What is a monoclonal antibody? Stable antibody that can be used over a period of time What does perspiration contain that is antimicrobial? Lysozyme Sebaceous glands produce sebum, few bacteria can metabolize sebum, causing? Acne (usually severe) What is mucous secreted by? Epithelial cells In the lower respiratory tract, what is mucous membrane covered with? Cilia (hair like protrusions) What comes under the Physiologic barriers? Temperature Low pH Soluble Factors (Lysozyme's, Interferons) 2/6 Name some soluble factors? Lysozymes Cytokines Acute Phase proteins Complement What are lysozymes and what do they do? - Lysozymes are a hydrolytic enzyme - Found in mucous secretion and tears - Destroys certain bonds in the peptidoglycan layer of bacterial cell wall. either alpha or beta. Bind certain recepWhat are interferons and what do they tors to cause reactions like: macrophage do? stimulation, T cell activation, and activation of NK cells. Monocytes Neutrophils What comes under the Phagocytic barri- Eosinophils ers? Macrophages *they kill and digest micro-organism in the phagolysosome (immune cells) Two types of inflammation 1. Acute (response to acute injury like a cut) 2. Chronic (occurs even without the acute injury or external stimuli) Heat (Calor) + Redness (Rubor) caused by vasodilation / widening of The inflammatory barrier is generally blood vessels triggered by LPS, which kicks starts this Swelling (Tumor) - Caused by increased repair process. What are the signs of vascular permeability inflammation? Pain (Dolor) + Loss of function (Functio Laesa) - Caused by mediator release What do phagocytes do? Engulf and destroy pathogens 1. Cells go to the endothelial wall of blood vessels (margination) How do phagocytes get to site of inva2. They go from capillary-endothelial sion? cells into tissue (diapedesis/extravasation) 3/6 3. They migrate through tissue into side of invasion (chemotaxis) Cell Derived mediators: - Arachidonic acid derivatives - Cytokines - Vasoactive amines Plasma Derived factors: - Acute Phase Proteins - Kinin system - Clotting & fibrinolytic system - Complement Inflammation is activated by one of two types of mediators, name? Prostaglandins and Leukotrienes - These substances cause inWhat are arachidonic acid derivatives? creased capillary permeability, vasodilation (widening of blood vessels), smooth muscle constriction What are examples of cytokines? - IL: 1, 6, 12, 17, 18, 8 - Tumour necrosis factors, interferons What are the vasoactive amines? Histamine - released in response to tissue injury, binds to receptors on nearby capillaries and venules, causing vasodilation and increased permeability. What is the acute phase protein produced by the liver? CRP - levels of this are raised for infection and inflammation, - Where kinin's usually present? - What activates them? - What happens after activation - What particular kinin stimulates pain receptors in skin - Blood stream (in inactive form) - Tissue injury - Vasodilation and increased permeability of capillaries - Bradykinin Immunity - MAC (membrane attack complex MAC C5-9) punches hole in membrane What does complement do in immunity, Inflammation - C3a and C5a increase inflammation and phagocytosis? vascular permeability and vasodilation. Activates lipoxygenase pathway of C5a, causing leukocyte activation, adhesion 4/6 and chemotaxis. Phagocytosis - C3b acts as opsonin, promotes phagocytosis - Vasodilation / increase in capillary permeability allow enzymes of blood clotting system to enter the injured tissue. - These enzymes signal for a casHow does the clotting & fibrinolytic syscade, delivering insoluble strands of fibtem work? rin (main component of blood clot) - These strands seal off injured area from rest of body, serving to prevent spread of infection. What happens once inflammation response has subsided? Tissue repair and regeneration begins. - Capillaries grow into the fibrin of the blood clot. - New connective tissue cells (fibroblasts), replace fibrin as clot dissolves. - As fibroblasts and capillaries accumulate, scar tissue forms. What are the four types of vaccines? -Live attenuated (whole organism) -Inactivated -Subunit -Toxoid - Use live organism (just with no pathogenicity / weak or attenuated) What are whole organism vaccines (live - Virulent pathogen is grown under abattenuated)? normal culture conditions - Usually no need for boosters What is a common issue for whole organism vaccines? - Reversion to wild type - Contamination with other viruses *less safe than inactivated What are inactivated vaccines? - Pathogen killed by heat or chemicals - This type of vaccine does require repeat boosters - Induces humoral response - Less strong immune response than live attenuated 5/6 What problem is posed when pathogen Heating process can hurt epitope strucis inactivated by heat / chemicals (inactiture vated vaccines)? What are subunit (purified) vaccines? - Use antigenic parts of pathogen (so they don't physically contain any pathogenic content) - Produce one of the weaker immune responses What are the three types of subunit vaccines? Protein Polysaccharide Conjugate What are toxoid vaccines? - Use toxin made by pathogen that causes the disease - Immunity is created to parts of the pathogen that cause disease, not entire pathogen itself. - Probably the safest, but induce the smallest immune response out of the four. What is passive immunization? - Individual acquires immunity through the transfer of antibodies formed by an immune individual or animal - No vaccine - Can be artificial or natural What is active immunisation? - Administration of an antigen to induce an immune response and immunological memory. - Immune system activates its own means, T-cells, antibodies etc. - Basically vaccines 6/6