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61 Cards in this Set
- Front
- Back
Immunity |
the immune's systems capacity to protect individuals from disease by recognizing and eliminating potential pathogens
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Pathogen
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potential disease-generating agent |
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List the 4 types of pathogens
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Bacteria, virus, parasite and fungi |
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Difference between nonspecific (Innate) immunity and specific (adaptive) immunity |
Nonspecific: provides the first defenses against pathogens regardless of the type of pathogen Specific: provides a stronger defense against a specific pathogen(s) and takes longer to develop |
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3 components of the Immune System |
1) Physical/Chemical Barriers 2) Leukocytes 3) Lymphoid tissues |
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The Physical and Chemical barriers consist of which 2 main branches? Describe the outer epidermis and inner dermis. |
- Skin and mucous - Outer Epidermis: epithelial cells and keratin, lacks blood cells - Inner dermis: sebaceous glands that secrete sebum |
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List the chemicals found under chemical barriers and where each is located |
Lysozymes: in the saliva HCl: in stomach Acid: in urinary tract (and vagina in females) Fatty acids:: in sebaceous glands |
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What are the first lines of defense
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physical and chemical barriers
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Antigen |
foreign or abnormal substance
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The three major lymphocytes |
B Lymphocytes (B cells) T Lymphocytes (T cells) Null cells |
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Null cells |
Lymphocyte cells that lack cell membrane components that are characteristic of B and T cells. Ex: natural killer cells (NK cells) |
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B cells (B lymphocyte cells)
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- when they come in contact with antigens, they develop into plasma cells - these plasma cells secrete antibodies (only for the antigen the b cell came into contact with) - the antibodies it secretes do not damage the bacteria but marks them for destruction |
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Antibodies (immunoglobulins)
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Proteins in the plasma and interstitial fluid that target specific antigens for destruction.
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T cells (T lymphocyte cells) |
- do direct damage to antigens - they contact infected, mutant and transplanted cells - take several days to develop into active cytotoxic T cells that destroy theses antigens |
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Which lymphocyte cells develop into active cytotoxic cells and how do they destroy antigens? |
-T cells - Cytotoxic T cells kill antigens by secreting molecules that form pores in the target cell's membrane - the rupture of its membrane causes the cell to fill with fluid (that seeps into it from outside) and bursts |
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3 categories of leukocytes |
1) Phagocytes 2) Lymphocytes 3) Tissue Cells of Hematopoietic Origin |
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Two cells considered tissue cells of hematopoietic origin
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Mast cells and dendritic cells
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All blood cells, mast cells and dendritic cells derive from where?
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bone marrow from the hematopoietic stem cells
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Mast cells |
- secrete histamine and other substances - found in skin and mucous membranes |
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Dendritic cells |
- able to phagocytose or endocytose cells - able to activate certain types of T cells - similar to macrophages |
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The 4 types of dendritic cells |
- Langerhans cells - Interstitial dendritic cells - myeloid cells - lymphoid dendritic cells |
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Lymphoid tissue |
- third component of the immune system - plays a major rule in defending the body against pathogens |
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The two types of lymphoid tissues |
1) Central lymphoid tissues 2) Peripheral lymphoid tissues |
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What are the central lymphoid tissues?
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Bone marrow, thymus and the fetal liver
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Lymphoid tissue type that are the sites of lymphocyte production and maturation |
Central lymphoid tissues
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Lymphoid tissue type that are the sites where lymphocytes generally contact pathogens (and other antigens) and become activated as part of the immune response |
Peripheral lymphoid tissues
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T and B cells mature in the _____________________ tissues and then upon full maturity, migrate to the _____________________ tissues. |
1) Central lymphoid tissues 2) Peripheral lymphoid tissues |
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What are the peripheral lymphoid tissues? |
The adenoids, tonsils, lymph nodes, spleen, appendix, lymph nodules of the gastrointestinal tract and Peyer's patch (regions in lining of the gastrointestinal tract) |
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Virulence
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The ability of a specific pathogen to cause a disease
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Smallest type of pathogen, needs a host to survive |
Virus |
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The transmission of this pathogen to another host, primarily through body secretions and excretions, is required for its survival
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Bacteria |
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Difference between gram-positive and gram-negative bacteria and the toxins each release. |
Gram-positive bacteria: take up cresyl violet - release exotoxins: cytotoxins, neurotoxins and enterotoxins Gram-negative bacteria: has enzymes that break up cresyl violet, preventing it from accessing the interior of the cell - have endotoxins located on its walls that activate certain aspects of the immune system to cause fever & other symptoms |
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Differences between cytotoxins, neurotoxins and enterotoxins
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Cytotoxins: attack host cells Neurotoxins: interefere with nerve signaling Enterotoxins: affect the lining of the gastrointestinal tract |
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In which two ways does bacteria cause disease?
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Through the invasion of tissues and release of toxins
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Vector |
An organism that transmits a parasite from one host to another |
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Pathogen that invades a host in their quest to obtain nutrients, harming the host in the process
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Parasite
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2 Main classes of parasites
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Protozoans: unicellular eukaryotic organisms Metazoans: multicellular animals w/ different tissue types (Ex: Worms - tapeworms and Arthropods- mice, lice) |
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Pathogen that absorbs nutrients from the environment and can cause infections on the skin or respiratory tract |
Fungi |
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The body's nonspecific defenses include:
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1) Physical barriers 2) Inflammation 3) Interferons 4) Complement System |
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Inflammation
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Series of events that causing accumulation of proteins, fluids and phagocytic cells in an area of tissue that has been injured or invaded by microorganisms
- triggered by microbial invasion or damage to tissue |
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Interferons
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small molecule that stimulates strong contractions in the smooth muscles of the bronchi, gastrointestinal tract, uterus and bladder - makes small blood vessels dilate (expand) and become leaky - stimulates nerve endings = twitching and pain - stimulates bronchial mucus secretion, tear formation and salivation |
Histamine |
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Interferons secreted by virus-infected cells
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Interferon- a and Interferon-b
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Interferon not secreted by virus-infected cells but active T cells and NK cells
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Interferon-y
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Perforins
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proteins that form pores in the infected or abnormal cell's membrane
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Cytokines
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any of a number of substances (interferon, interleukin) that are secreted by certain cells of the immune system and have an effect on other cells
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The three ways the complement system can be activated (name the pathways)
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1) Classical 2) Lectin 3) Alternative |
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What initiates the classical pathway? Is it specific or non-specific |
Binding of antibody to a pathogen Specific |
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What initiates the lectin pathway? Specific or non-specific?
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Binding of lectin in blood to mannose on bacteria's surface Non-specific |
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What initiates the alternative pathway? Specific or non-specific?
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Binding to carbohydrates on the surface of the bacteria. Initiated by: presence of yeast cell wall fragments, snake venom, normal hydrolysis of C3 Non-specific |
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What are the four mechanisms of protection that result from the complement system? |
1) Opsonization
2) Leukocyte Recruitment 3) Histamine Secretion 4) MAC (Membrane-Attack Complex) |
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Opsonization |
Antibodies covalently bonding to pathogens and acting as opsonins (making them easier to phagocytose) |
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MAC
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Membrane-Attack Complex - pore-forming proteins pierce holes in the bacterial membrane/surface = fluid fills = bacteria swells = bursts (same effect as Perforins and Cytotoxic T cells |
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Humoral Response -caused by what cell - defends against what and where |
- caused by B cells - defend against bacteria, toxins and viruses in the body's fluids |
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Cell-Mediated Response - caused by what cell - defends against what and where |
- by T cells - defend against bacteria and viruses hidden within infected body cells |
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Effector cells
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- short-lived cells - combat the same antigen that stimulated their production (ex: plasma cell which is a B cell) |
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Memory cells |
- long-lived cells - have membrane receptors specific for the same antigen |
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Classical pathway vs. alternative |
C: antibody binding, slower, specific A: carbohydrate binding to bacteria surface, non-specific, faster |