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45 Cards in this Set
- Front
- Back
Immune response |
Physiological process coordinated by the immune system to eliminate foreign substances |
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Antigen |
Foreign substances |
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Innate immunity |
Inborn, ancient protection existing in one form or another in all eukaryotic organisms |
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Adaptive immunity |
Immunity that matures over time with responses tailored to the pathogens encountered |
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Immune |
Specific protection conferred by adaptive immunity |
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Susceptible |
Vulnerability or lack of immunity |
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Characteristics of innate immunity |
Present at birth Defense against any pathogen 1st and 2nd lines of defense |
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Components of the first line of defense |
Intact skin Mucous membranes GI tract Chemical factors Normal microbiota |
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How does intact skin defend |
- Stratified squamous epithelium provides thick, tough barrier - Contains keratin (insoluble protein) - Sloughing of outermost layer and removing transient microbes - Low moisture inhibits microbes |
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How do mucous membranes defend |
- Mucous traps microbes - Cilia move microbes away from lungs by ciliary escalator - In respiratory, digestive, and urinary tracts |
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How does the GI tract defend |
- Peristalsis, defecation, vomiting expel microbes from GI tract ( usually in reponse to microbial toxins) - acidic pH in stomach kills most microbes |
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How do chemical factors defend |
- Tears, saliva, mucous have lysozyme (enzyme that breaks down peptidoglycan) - Urine, sebum, gastric juices have acidic pH - Sweat has high salt and lysozymes |
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How do normal microbiota defend and example |
Keep other microbes out by secreting chemicals, should not be eliminated with handwashing - Ex. E. coli in large intestine produces chemicals to inhibit growth of salmonella and if conditions change it can become an opportunistic pathogen |
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Physical barriers example |
Intact skin |
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Mechanical barrier example |
Mucous membranes, GI tract |
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Chemical barrier example |
GI tract (stomach acid), chemical factors |
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Normal microbiota characteristics |
Good microbes Keep other microbes out by secreting chemicals Should not be eliminated with handwashing or cleaning products |
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Opportunistic microbe and example |
Cause disease when host is weakened - Ex: E. coli, S. aureus |
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Components of second line of defense and examples |
- Formed elements: cells in blood (leukocytes, erythrocytes, thrombocytes) - Phagocytosis: neutrophils, monocytes - Inflammation: heat, pain, redness, swelling are symptoms - Fever: endotoxin releases pyrogens to induce fever - Antimicrobial substances: histamine, prostaglandin, leukotrienes, cytokines, interferons |
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Formed elements and what they do |
Leukocytes (WBC): fight infection Erythrocytes (RBC): transport O2 Thrombocytes (platelets): clot formation |
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Natural killer cell characteristics |
Lymphocytes Related to T cells but don't act specifically |
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Mast cell characteristics |
Specialized tissue cells similar to basophils that trigger local inflammatory reactions (allergic symptoms) |
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Which leukocytes are granulocytes |
Neutrophils Basophils Eosinophils Mast cells |
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Which leukocytes are agranulocytes |
Monocytes (macrophages, dendritic cells) Lymphocytes (B, T, NK cells) |
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Neutrophils function, %, characteristics |
Phagocytes that are active during initial infection 60-70% Leave blood and enter tissues |
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Lymphocytes function, %, characteristics |
Lead to antibody production 20-25% In tonsils, spleen, red bone marrow, lymph nodes |
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Monocytes function, %, characteristics |
Phagocytes (macrophages) 3-8% Largest, macrophage/ dendritic cells |
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Eosinophils function, % |
Produce toxic proteins against certain parasites, reduce inflammation 2-4% |
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Basophils function, % |
Release histamine .5-1% |
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Leukocytosis |
Increase in leukocytes (meningitis, mononucleosis, appendicitis) |
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Leukopenia |
Decrease in leukocytes (chemotherapy, radiation, some viral infections like HIV/AIDS) |
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Phagocytosis and steps |
Process of investing a pathogen or cellular debris Steps: 1. Chemotaxis: chemical attraction of phagocyte to pathogen by chemical receptors 2. Adherence: attachment to pathogen 3. Ingestion: engulfs pathogen 4. Digestion: enzymes (lysozyme) breaks down pathogen |
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Causes of inflammation |
Microbial infection, cut, burn, chemicals, allergies, etc |
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Symptoms of inflammation |
Heat (calor) Pain (dolor) Redness (rubor) Swelling (tumor) |
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What is a fever and its benefits |
Systemic response causing abnormally high body temperature Increases metabolism, inhibits multiplication of many viruses, fungal pathogens, and Mycobacterium |
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What occurs during a fever |
- Bacteria or viruses release chemicals called pyrogens which elevate body's thermostat (ex. Endotoxin) - Hypothalamus resets thermostat - Blood vessels constrict, shivering, chills |
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Function and example of histamine (antimicrobial substance) |
Causes vasodilation Released by tissues and basophils |
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Function and example of prostaglandins (antimicrobial substance) |
Intensify effects of histamine, help phagocytes move through capillary walls (vasodilation) Released from damaged cells |
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Function and example of leukotrienes (antimicrobial substance) |
Cause vasodilation, help attach phagocytes to pathogen Produced by mast cells and basophils |
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Function and example of cytokines (antimicrobial substance) |
Cause vasodilation, involved in cell communication Used in adaptive immunity |
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Function and example of interleukin (antimicrobial substance) |
Sends messages between leukocytes and stimulates immune responses Several types IL-1, IL-2, etc |
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Function and example of interferon (antimicrobial substance) |
Infected cell signals neighboring cells to produce antiviral proteins, activates macrophages Protects against viruses |
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Compliment system |
Series of proteins that destroy bacteria and some viruses activated in a cascade reaction through central protein (C3) Compliments antibodies |
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Three outcomes of compliment system |
Phagocytosis Inflammation Membrane attack complex (cell lysis) |
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Classical pathway |
Antibody -> C3 -> C3a (inflammation) and C3b (phagocytosis and C5) C5 -> C5a (inflammation) and C5b (membrane attack complexes) C6-9 causes cell lysis |