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40 Cards in this Set
- Front
- Back
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What is immunity?
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It a biological defense of avoiding infection, disease, and other biological invasion.
Involves non specific and specific components. Other components adapt themselves to a new disease. |
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Non specific
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They acts as barriers or as eliminators
There are two types of barriers Physical (skin, mucus, etc.) and chemical (pH, lysozyomes, stomach acid) is always present and does not have immune memory,Normal flora, |
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Neutrophile
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killers of bacteria (PMN’s) are present in the highest numbers
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Eosinophils
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active in worm and fungal infection, allergy, and inflammation reactions
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Basophils
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inflammation and allergy
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Mast cell
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responsible for most of the allergy, Tissues.
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Macrophages
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are big eater in the tissues
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Lymphatic system
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– Lymph nodes
• Houses immune cells |
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• Spleen
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– Filters pathogens in the blood
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• Thymus
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– Site of T cell maturation
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GALT
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–gut associated lymphoid tissue
– Peyer’s patches - intestines |
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Whole blood contains
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– Red blood cells – carry O2 and CO2
– White blood cells • Leukocytes |
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Plasma
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Water
• Proteins • Chemicals |
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Plasma proteins
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• Blood plasma contains
– Clotting factors – Complement – Antibodies – Molecules not related to defense |
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• Serum
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is missing clotting proteins
– From clotted blood |
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Leukocytes
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neutrophils, eosinphils, basophils, and mast cells
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Innate immunity
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– Nonspecific resistance
– Protects us against all pathogens – Over-the-counter defenses |
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Adaptive immunity
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– Specific resistance
– Defends against specific pathogens – Prescription defenses |
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Nonspecific host defenses
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– Innate
immunity • Always present • Immediately effective • No immune memory – work at the same speed each time |
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Inflammation
Rubor |
– redness
– From increased vascular permeability (more blood to the area) |
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Inflammation
Calor |
– warmth
– From the increase in blood |
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Inflammation
Tumor |
– swelling
– From the increased amount of fluids leaking into the tissue |
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Inflammation
Dolor |
– pain
– From the stimulation of the nerve endings |
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Phagocytosis
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= eating of cells
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Neutrophils (PMNs)
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are present in the highest
numbers in blood |
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Macrophages
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(“big eaters”) in the tissues encounter
the pathogen first • Secrete cytokines ---> inflammation, systemic responses |
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Membrane receptors
(on phagocytes) |
bind
commonly shared bacterial molecules – LPS (endotoxin, Gram -) – Lipoteichoic acid (Gram +) – Patterns of sugars (PAMPs – pathogen-associated molecular patterns) – Nucleic acids |
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Pathogen recognition
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• Phagocyte must bind pathogen to begin
phagocytosis |
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opsonins
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Phagocytosis is easier • if the pathogen is
coated with antibodies or complement |
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Macrophages
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produce chemokines to
increase inflammation |
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Lymph nodes
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contain specific B and T cells
– Make the adaptive immune response – Produce the immune memory cells |
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Macrophage lymphokines
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Signal hypothalamus to increase body
temperature = fever • Signal liver to produce acute phase proteins = opsonins that aid phagocyte binding of pathogen • Signal bone marrow to release more PMNs |
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Pathogen destruction
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• Pathogen is killed by enzyme digestion,
toxic oxygen molecules, and defensins • Some pathogens resist killing and live in phagosome or escape to cytosol (Mycobacterium tuberculosis, Listeria monocytogenes) |
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Complement
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Lyses bacteria
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Interferon
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Stops virus infection
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Anti-Viral interferons
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IFNa (alpha) and IFNb (beta) made by virusinfected
cells • Not virus-specific |
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Gamma interferon
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• IFNg is made by T cells
• Activates macrophages and neutrophils to kill bacteria • [ IFNg is not antiviral ] |
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Natural Killer Cells
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• cells recognize virus-altered receptors and kill
virus-infected cells (also tumor cells) • All nucleated cells in body have these membrane receptors • cells can “recognize” cells that are infected • Stimulate those cells to apoptose |
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Stages of complement
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-Initiation
C1 binds to antibodies -Amplification and cascade -Polymerization More subunits come together and bind on the surface -Membrane attack Final product is an enzyme that blasts a hole |
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• IFNg
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is made by T cells
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