Term
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Definition
| Lack of resistance to a disease |
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Term
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Definition
| Ability to ward of disease |
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Term
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Definition
| Defenses against any pathogen |
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Term
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Definition
| Immunity or resistance to a specific pathogen |
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Term
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Definition
First line of defense: Intact skin, mucous membranes and their secretions, normal microbiota
Second line of defense: Phagocytes (such as neutrophils, eosinophils, dendritic cells, and macrophages), inflammation, fever, antimicrobial substances
Third line of defense: Specialized lymphocytes - T cells and B cells, Antibodies |
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Term
| Skin (first line of defense) |
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Definition
Epidermis consists of tightly packed cells with:
- keratin, a protective protein
- dry
- high salt concentration
- sebum
- low pH
- lysozyme in sweat |
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Term
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Definition
- microbial antagonism/competitive exclusion
- commensal microbiota |
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Term
| Microbial antagonism (competitive exclusion) |
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Definition
| Normal microbiota compete with pathogens or alter the environment |
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Term
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Definition
One organism (microbe) benefits and the other (host) is unharmed
- May be opportunistic pathogens |
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Term
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Definition
Mucus - traps microbes
Ciliary escalator - microbes trapped in mucus are transported away from the lungs
Lacrimal apparatus - washes eye
Saliva - washes microbes off
Urine - flows out
Vaginal secretions - flow out; low pH |
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Term
| Differential white cell count |
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Definition
| Percentage of each type of white cell in a sample of 100 white blood cells |
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Term
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Definition
Neutrophils - 60-70%
Lymphocytes - 20-25%
Monocytes - 3-8%
Eosinophils - 2-4%
Basophils - 0.5-1% |
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Term
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Definition
Inflammation
Fever
Antimicrobial substances |
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Term
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Definition
Vasodilation (histamine, kinis, prostaglandins, and leukotrienes)
Redness, swelling (edema), pain, heat |
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Term
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Definition
| Ingestion of microbes or particles by a cell, performed by phagocytes |
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Term
| Lymphocytes (adaptive immunity - third line of defense) |
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Definition
B cells - humoral immunity; produce antibodies
T cells - cell mediated immunity |
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Term
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Definition
| A substance that causes the body to produce specific antibodies or sensitized T cells |
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Term
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Definition
| Specific site on the antigen that interacts with antibodies |
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Term
| Results of antigen-antibody binding |
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Definition
Agglutination
Activation of complement
Opsonization
Neutralization
Antibody-dependent cell-mediated cytotoxity |
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Term
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Definition
| Reduces number of infectious units to be dealt with |
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Term
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Definition
| Causes inflammation and cell lysis |
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Term
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Definition
| Coating antigen with antibody enhances phagocytosis |
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Term
| Antibody-dependent cell-mediated cytotoxicity |
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Definition
| Antobodies attached to target cell causes destruction by macrophages, eosinophils, and NK cells |
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Term
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Definition
| Blocks adhesion of bacteria and viruses to muscosa |
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Term
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Definition
Produces antibodies
- Globular proteins called immunoglobins
- 5 classes
-- IgG - enhance phagocytosis; neutralize toxins and viruses; protects fetus and newborn
-- IgA - mucosal protection
-- IgM - Agglutinates microbes; first antibody produced in response to infection
-- IgE - on mast cells, on baophils, and in blood, allergic reactions; lysis of parasitic worms
-- IgD - function not clear |
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Term
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Definition
T cells respond to antigen by T-cell receptors (TCRs)
T cells require antigen-presenting cells (APCs) macrophages, B cells
Two major classes of T cells
- CD4+ - helper cells (activates other immune cells)
- CD8+ - cytotoxic cells (directly kills infected cells) |
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Term
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Definition
Chemical messengers
Overproduction leads to cytokine storm |
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Term
| Different types of cytokines |
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Definition
Interleukin-1 (IL-1) - Stimulates Th cells in presence of antigens; attracts phagocytes
Interleukin-2 (IL-2) - Proliferation of antigen-stimulated CD4+ T helper cells, proliferation and differentation of B cells; activation of CD8+ T cells and NK cells
Interleukin-12 (IL-12) - Inhibits humoral immunity; activates Th1 cellular immunity
TNF-alpha - Promotes inflammation
IFN-gamma - Stimulates macrophage activity |
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Term
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Definition
| The amount of antibodies in serum |
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Term
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Definition
| Occurs after initial contact with antigen |
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Term
| Secondary (memory or anamnestic) response |
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Definition
| Occurs after second exposure |
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Term
| Naturally acquired active immunity |
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Definition
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Term
| Naturally acquired passive immunity |
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Definition
| Transplacental or via colostrum |
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Term
| Artificial acquired active immunity |
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Definition
| Injection of antigen (vaccination) |
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Term
| Artificially acquired passive immunity |
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Definition
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