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immune system

immune system
免疫系统

Definitions

1. being highly resistant to a disease because of the formation of humoral antibodies or the development of immunologically competent cells, or both, or as a result of some other mechanism, as interferon activities in viral infections. 2. characterized by the development of humoral antibodies or cellular immunity, or both, following antigenic challenge. 3. produced in response to antigenic challenge, as immune serum globulin. immune response the reaction to and interaction with substances interpreted by the body as not-self, the result being humoral and cellular immunity. Called also immune reaction. The immune response depends on a functioning thymus and the conversion of stem cells to B and T lymphocytes. These lymphocytes contribute to antibody production, cellular immunity, and immunologic memory.Disorders of the Immune Response. Pathologic conditions associated with an abnormal immune response (immunopathy) may result from (1) immunodepression, that is, an absent or deficient supply of the components of either humoral or cellular immunity, or both; (2) excessive production of gamma globulins; (3) overreaction to antigens of extrinsic origin, that is, antigens from outside the body; and (4) abnormal response of the body to its own cells and tissues.Those conditions arising from immunosuppression include agammaglobulinemia (absence of gamma globulins) and hypogammaglobulinemia (a decrease of circulating antibodies). Factors that may cause or contribute to suppression of the immune response include (1) congenital absence of the thymus or of the stem cells that are precursors of B and T lymphocytes; (2) malnutrition, in which there is a deficiency of the specific nutrients essential to the life of antibody-synthesizing cells; (3) cancer, viral infections, and extensive burns, all of which overburden the immune response mechanisms and rapidly deplete the supply of antigen-specific antibody; (4) certain drugs, including alcohol and heroin, some antibiotics, antipsychotics, and the antineoplastics used in the treatment of cancer.Overproduction of gamma globulins is manifested by an excessive proliferation of plasma cells (multiple myeloma). hypersensitivity is the result of an overreaction to substances entering the body. Examples of this kind of inappropriate immune response include hay fever, drug and food allergies, extrinsic asthma, serum sickness, and anaphylaxis.Autoimmune diseases are manifestations of the body's abnormal response to and inability to tolerate its own cells and tissues. For reasons not yet fully understood, the body fails to interpret its own cells as self and, as it would with other foreign (not-self) substances, utilizes antibodies and immunologically competent cells to destroy and contain them. Disorders of the Immune Response. Pathologic conditions associated with an abnormal immune response (immunopathy) may result from (1) immunodepression, that is, an absent or deficient supply of the components of either humoral or cellular immunity, or both; (2) excessive production of gamma globulins; (3) overreaction to antigens of extrinsic origin, that is, antigens from outside the body; and (4) abnormal response of the body to its own cells and tissues.Those conditions arising from immunosuppression include agammaglobulinemia (absence of gamma globulins) and hypogammaglobulinemia (a decrease of circulating antibodies). Factors that may cause or contribute to suppression of the immune response include (1) congenital absence of the thymus or of the stem cells that are precursors of B and T lymphocytes; (2) malnutrition, in which there is a deficiency of the specific nutrients essential to the life of antibody-synthesizing cells; (3) cancer, viral infections, and extensive burns, all of which overburden the immune response mechanisms and rapidly deplete the supply of antigen-specific antibody; (4) certain drugs, including alcohol and heroin, some antibiotics, antipsychotics, and the antineoplastics used in the treatment of cancer.Overproduction of gamma globulins is manifested by an excessive proliferation of plasma cells (multiple myeloma). hypersensitivity is the result of an overreaction to substances entering the body. Examples of this kind of inappropriate immune response include hay fever, drug and food allergies, extrinsic asthma, serum sickness, and anaphylaxis.Autoimmune diseases are manifestations of the body's abnormal response to and inability to tolerate its own cells and tissues. For reasons not yet fully understood, the body fails to interpret its own cells as self and, as it would with other foreign (not-self) substances, utilizes antibodies and immunologically competent cells to destroy and contain them.





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