The Immune System Chapter 43 Nonspecific Immunity Helps prevent the entry of microbes: Skin and mucus membranes 1st line of defense Helps prevent the spread of microbes:
Acidify the skin Saliva, tears have antimicrobial proteins Nostril hairs & mucus Stomach acids Phagocytes destroy themselves and pathogen Inflammatory response brings blood and therefore more phagocytes to the area Antimicrobial proteins either directly attack microbes or interfere with their reproduction Specific Immunity The body responds to a particular type of
infectious agent Four components: Specificity Diversity Memory Self/non-self recognition Lymphocytes provide the specificity of the immune system Specificity
The immune system is able to recognize and eliminate particular microorganisms and foreign molecules This is the job of the lymphocytes Antigen a foreign substance that elicits a specific response by lymphocytes Antibody an antigen-binding protein produced by lymphocytes that functions as the effector in an immune response; these tag the invading cell for destruction Diversity
The ability to respond to the wide variety of antigens which enter the body is based on the diversity of antigen-specific lymphocytes present in the system The primary immune response is the making of lymphocytes during the 1st exposure to the antigen A secondary immune response occurs when the body is exposed to the antigen again Memory The ability to recognize a previously encountered antigen This is based on memory cells which are produced during the primary immune
response Memory cells are not active during the primary response but survive in the system for a long time This is acquired immunity Self/non-self recognition The immune system is able to distinguish between the bodys own molecules and foreign antigens It develops before birth when the lymphocytes begin to mature The failure of this ability to recognize self leads to autoimmune disorders that destroy the bodys own tissues Blood groups and transfusion
An example of self/non-self recognition Type A blood produces A antigen; makes B antibodies Type B blood produces B antigen; makes A antibodies Type AB blood produces A and B antigen; makes neither A nor B antibodies Type O blood produces neither A nor B antigen; makes both A and B antibodies Universal donor Type O: no antigens Universal recipients Type AB: no antibodies
Immune Response: either humoral or cell-mediated Humoral immunity antibodies produced in response to toxins, bacteria, and viruses present in the body fluids (the humors) Cell-mediated immunity the response to intracellular bacteria, viruses, fungi, protozoa, worms, transplanted tissues, and cancer cells Achieving Immunity Active immunity conferred by recovery from an infectious disease
Depends on response by the persons own immune system May be acquired through illness or vaccination Passive immunity transferred from one person to another Pregnant or nursing mother to child Artificially from an animal or another person already immune to the disease Abnormal immune function
Allergies a hypersensitivity to an environmental antigen Autoimmune disorders an immune system reaction against self Anaphylactic shock a life-threatening condition associated with some allergens such as insect stings or peanuts; epinephrine may be used as an anecdote lupus erythematous, rheumatoid arthritis, multiple sclerosis, insulin-dependent (juvenile) diabetes -?
Immunodeficiency diseases immune system is not working Hodgkins disease AIDS
