ADAPTIVE IMMUNITY. *To adapt means to become suitable, and adaptive immunity can become “suitable” for and respond to almost any foreign antigen. *Adaptive immunity is: -specific -and is carried out by lymphocytes and macrophages. *The majority of lymphocytes are -T cells and
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*To adapt means to become suitable, and adaptive immunity can become “suitable” for and respond to almost any foreign antigen.
*Adaptive immunity is:
-and is carried out by lymphocytes and macrophages.
*The majority of lymphocytes are
-T cells and
* When activated some B cells will divide many times and become plasma cells that produce antibodies to a specific antigen.
*The mechanisms of immunity that involve T cells and B cells are specific
. A macrophage has receptor sites for foreign chemicals such as those of bacterial cell walls or flagella, and may phagocytize just about any foreign material it comes across
1-cell-mediated immunity which involves:
2-antibody-mediated immunity (or humoral immunity), which involves:
- T cells,
- B cells,
1- chemically destroy foreign antigens by disrupting cell membranes as destruction of cells infected with viruses
2- produce cytokines, which are chemicals that attract macrophages to the area to phagocytize the foreign antigen and cellular debris.
3-produce(with helper T) feedback chemicals to limit the immune response once the foreign antigen has been destroyed ( T suppressor).
antigen, this time by B cells as well as by
macrophages and helper T cells.
The sensitized helper T cell presents the foreign antigen to B cells, which divide many times, and two types of cells are formed:
1- memory B cells, which will remember the specific antigen
2-plasma cellthat produce antibodies
specific for this one foreign antigen.
*are proteins shaped somewhat likethe letter Y.
* Antibodies do not themselves destroy foreignantigens, but rather become attached to such antigensto “label” them for destruction.
*Each antibody produced is specific for only one antigen forming antigen antibody complex labelled for phagocytosis or fixation by complement
*millions of different antigen-specific antibodies can be produced.
-the injection of immune globulins (gamma globulins or preformed antibodies) after presumed exposure to a particular pathogen.
Such immune globulins are available for German measles, hepatitis A and B ,tetanus and botulism (anti-toxins), and rabies
-it is only for weeks or months
antibodies and may be stimulated by natural or artificial means.
-Naturally acquired active immunity means
that a person has recovered from a disease and now has antibodies and memory cells specific for that pathogen.
-Artificially acquired active immunity is the result of a vaccine that has stimulated production of antibodies and memory cells
The purpose of vaccines is to prevent disease. A vaccine contains an antigen that the immune system will respond to, just as it would to the actual pathogen.
- The types of vaccine antigens are a killed or weakened (attenuated) pathogen, part of a pathogen such as a bacterial capsule, or an inactivated
bacterial toxin called a toxoid
-Allergens include plant pollens, foods, chemicals in cosmetics, antibiotics such as penicillin, dust, and mold spores.
-Such allergens are themselves harmless as most people, for example, can inhale pollen, eat peanuts, or take penicillin with no ill effects.
-infections as influenza and to what
are called secondary infections, such as pneumonia
-Autoimmune disorders as rheumatoid arthritis
-cancer is also higher