1. Peer Support: Francesca Peters + Reesha Ranat

2. A system of biological structures and process that exits to protect against disease Can be divided based on response time: INNATE VS ADAPTIVE Or based on components: CELLULAR and HUMORAL

5. T-Lymphocytes: ADAPTIVE Cytotoxic T cells Involved in receptor-mediated destruction of antigen-presenting host cells Activated Tc cells bind to host cells expressing Ag-presenting MHC-1 molecules T-helper cells Involved in Tc and B cell activation and chemotaxis through cytokine release B-Lymphocytes:ADAPTIVE Antibody producing cells. Mature on activation by Th cells -> dived into Plasma cells (antibody production) and Memory cells (immunological memory for re-exposure situations)

6. Phagocytosis = recognition & engulfing of microbes, which are then killed by the release of toxic chemicals into the enclosed vacuole 2 types: Polymorphonuclear leukocytes (multi-nucleate white cell) = NEUTROPHILS -> INNATE Mononuclear phagocyte system (1 nucleus cells) = MONOCYTES (in circulation) + MACROPHAGES (in tissues) -> INNATE + ADAPTIVE

8. DENDRITIC CELLS: Phagocytosis and processing of antigen material to present antigen to T-cells Act as intermediate messengers between innate and adaptive system EOSINOPHILS: Pro-inflammatory cells which mediates the process of inflammation Main cell involved in allergy + hypersensitivity Histamine-releasing cells BASOPHILS: Pro-inflammatory cells also involved in allergy Contain heparin – prevents blood clotting too quickly - + histamine Activated under ectoparasitic infections MAST CELLS: Tissue resident immune cells with histamine and heparin rich granules Involved in allergy, anaphylaxis, wound healing and pathogen defense

9. NK cells = lymphocytes that perform both direct and antibody- dependent cell cytotoxicity -> INNATE Produce pore-forming molecules which are inserted into target cell membrane into which cytotoxic signalling molecules are pumped Detect cells that lack MCH molecules -> stimulates NK cell activation

10. Complement Protein (enzyme) system involved in opsonisation, chemotaxis and cell lysis Acute Phase Proteins Group of proteins whose plasma concentrations are responsive to inflammation  good diagnostic tool Antibodies Proteins produced by B-cells which act as receptors for antigens. Involved in antigen neutralisation Antibodies are antigen-specific

13. InnateAdaptive Primary line of defenceSecondary line of defence Immediate responseDelayed response Recognises certain threatsRecognises all threats No antigen presentationAntigen presentation No clonal selectionClonal selection No immunological memoryImmunological Memory

14. MHC = Major Histocompatibility Complex HLA = Human Leukocyte Antigen system MHC = HLA -> HLA tends to be used when referring to genes Cell surface molecules which mediate interactions with cells and other body cells. Determines organ donor-recipient compatibility and susceptibility to autoimmunity. MHC 1 molecules = all human cells. EXCEPT? presents host, viral or neoplastic antigens Tc cells MHC II molecules = Ag-presenting cells ONLY presents ingested microbial antigens to Th cells CD4+ (Th) cells interact with MHC II (2 x 4 = 8) CD8+ (Tc) cells interact with MHC 1 (1 x 8 = 8)