Immunology & Rheumatology L Immune System L Complete Guide 2023

Innate immunity {Ans: } Arm of the immune system that is *present from birth and present before the onset of infection* that constitutes *non-specific immune mechanisms* for defense against pathogens.Acquired Immunity {Ans: } Requires *recognition specificity* to foreign, non-self, antigens. Must be *induced b*y other immunoregulatory agents, usually part of the *innate immune system*, to become active against infections or tumors. Properties include: 1.* Antigen-specificity*- recognizes antigens, proteins, carbohydrates, lipids, or nucleic acids. 2. *Memory*- Results in increased reactivity upon repeated antigen or infectious agent exposure. 3. *Regulation*- Discrimination between* self and non-self *to prevent autoimmune reactions.Components of Acquired immunity {Ans: } *B- lymphocytes* which differentiate into plasma cells that produce antibodies. *T-lymphocytes: T-helper cells* which activate macrophages and other lymphocytes, *Cytotoxic T-cells *which kill infected or tumor targets, *Regulatory T-cells* which down-regulate, suppress or tolerize other lymphocytes.Antigen presenting cells (APCs) {Ans: } Cells that can ingest foreign molecules or pathogens and display the antigens on the cellular surface resulting in activation of humoral and adaptive responses. Includes: Macrophages, Dendritic cells, Langerhan's cells.Immunoglobulins {Ans: } Aka Antibodies, produced by B-cells and have antigen-specific receptor cells. Consist of 2 heavy chains and 2 light chains linked via disulfide bridges. 5 sub-types: