BSC 2011 Lecture Notes - Lecture 15: Cytotoxic T Cell, Adaptive Immune System, Natural Killer Cell
21 Oct 2016
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Document Summary
Animals have various means of defense against pathogens. Immunity is the ability to avoid disease when invaded by a pathogen. Saltiness and normal skin flora prevent entrance of pathogens. Phagocytes: recognize invading cells and ingest them by phagocytosis. Natural killer cells: type of lymphocyte that induce apoptosis in virus- infected or cancerous cells. Inflammation: coordinated innate immune response to injury/infection, blood vessels dilate and plasma and phagocytes move into damaged tissue, symptoms. Redness, swelling, pain due to dilation of the vessels and pressure on nerve endings. Mast cells (wbc) damaged cells: attracted to damaged tissues, release histamine and tumor necrosis factor (proteins, acquired (adaptive) immunity. Diversity of receptors to recognize different antigens. Ability to amplify those lymphocytes that recognize the specific pathogen: clonal selection- whatever cells recognize the pathogen present are mobilized. Ability to distinguish between self and non-self and remove self-reactive lymphocytes: clonal deletion. Hummoral immunity: antibody productions, b lymphocytes. Cellular immunity: kill infected cells, cytotoxic t lymphocytes (tc)
