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Immunity
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Infectious disease: pass between people due to germs
Noninfectious: caused by genetics or lifestyle
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Infection Prevention Wash your hands Eat well-cooked food Avoid foreign bodily fluid
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Pathogens enter the body through an orifice (mouth, nose, genitals, wounds)
Vector: something that carries a pathogen and transmits it to healthy cells Insects, food
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First line of defense: Non-specific immunity
Mucous membranes Skin Cilia in nasal passages
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Acidic from oil + sweat First line of defense Non-specific immunity
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White blood cells! Basophil
Makes chemicals (histamine) to cause inflammation in bloodstream Mast cell Makes chemicals (histamine) that cause inflammation in body tissues White blood cells!
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Engulfs dead/damaged body cells + bacteria; phagocyte
Macrophage Engulfs dead/damaged body cells + bacteria; phagocyte Neutrophil Engulf pathogen + invaders; phagocyte Infantry Eosinophil Poisons parasites
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Lymphocyte Specific response Destroys infected body cells + makes proteins that inactivate pathogens T cells: helpers + killers B cells: make antibodies
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Immunological Proteins Complement proteins:
Punch holes in pathogens’ cell membrane Attract phagocytes Cause microbes to stick of blood vessels’ walls to be destroyed by phagocytes
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Immunological Proteins Antibodies: made by B cells (lymphocytes)
Deactivate pathogen by binding its membrane proteins Make pathogens clump so phagocytes can more easily find them Activate complement proteins Bacterium Virus Bacteria Soluble antigens Foreign cell Complement proteins MAC Pore Enhances Phagocytosis Leads to Cell lysis Macrophage
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Antibody molecules Antibodies are the secreted form of the B-cell receptor.
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Immunological Proteins Interferons: produced by infected cells
Alarm call to other cells to protect themselves
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Active/acquired immunity: body responds to a specific pathogen
Passive immunity Genetic immunity: virus cannot infect your species Inherited immunity: mom passes antibodies through umbilical cord or breast milk Active/acquired immunity: body responds to a specific pathogen Learns to fight it so upon next exposure, the immune system reacts quickly + efficiently
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Nonspecific: 1 size fits all
Specific vs nonspecific responses Nonspecific: 1 size fits all Inflammation: blood vessel becomes leaky, white blood cells rush to infection site Fever: mast cells + macrophages release chemicals that stimulate hypothalamus to increase body temp capillary wall extracellular space white blood cell 37.7°C or 100°F stimulates interferon production: prevent viruses from spreading Increase white blood cell maturity rate High fever 39°C or 103°F = enzyme denaturation, seizure, brain damage, death
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Specific response: customized
Antigens: marker proteins, flags on cell surface Acquired immunity: produce memory cells to quickly attack foreign antigens if ever encountered again Cellular + humoral immunity
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Specific response: customized
Cellular immunity Phagocyte engulfs intruder and presents antigens Antigen-presenting cell T cells activated by antigen-presenting cell Activated T cells burst infected cell Memory T cells: reserves pathogen antigens T cell receptors activated T cells memory T cells
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B cell engulfs pathogens + displays antigens
Humoral immunity B cell engulfs pathogens + displays antigens T cell activates B cell: differentiates into memory and active B cells Activated B cells make 2,000 antibodies/second B cell T cell pathogen memory B cells activated B cells antibodies
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Tissue rejection: recipient’s immune system fights donated tissue
Immunosuppressants Immune system attacks healthy body cells: autoimmune diseases Severe Combined Immunodeficiency (SCID): humoral + cell-mediated branches are impaired
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Staying Healthy Antiseptics: chemicals (soap, vinegar, rubbing alcohol) that kill pathogens. Nonspecific Antibiotics: target 1 bacterium/fungus. Specific
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Antibiotic resistance: bacteria mutate, evade antibiotics
A bacterium carries genes for antibiotic resistance on a plasmid. A copy of the plasmid is transferred through conjugation. Resistance is quickly spread through many bacteria.
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Vaccine: trains immune system Whole dead bacteria or viruses
Live attenuated vaccines (weakened strain) Component vaccine: parts of pathogen containing antigen Toxoid vaccine: inactivated bacterial toxins Antigens in a vaccine trigger an immune response, and memory B cells are made. 1 memory B cells A memory B cell is stimulated when the real pathogen binds to it. 2 The B cell quickly activates and makes antibodies that fight the pathogens before you get sick. 3
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Allergy: oversensitivity to nonpathogens
Anaphylaxis: great deal of histamine causes airways to tighten, blood vessels to leak
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Autoimmune disease: body attacks self
Type I diabetes: attack pancrease, cannot produce insulin
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Leukemia: cancer of bone marrow
Bone marrow produces immature white blood cells To compensate, it produces more and more As a result, bone marrow produces fewer red blood cells + platelets Treatment Chemotherapy, radiation + bone marrow transplant Risks Graft-versus-host-disease Opportunistic infections
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