IMMUNE SYSTEM BEN, LYSSA AND LINDSAY

TERMS TO KNOW 1.Immunity- Ability of the body to protect itself from foreign substances and cells, including disease causing agents 2. Inflammatory Response- Tissue Response to injury that is characterized by redness, pain and swelling 3. Histamine- Substance produced by basophils in blood mast cells in connective tissue that causes capillaries to dilate 4. Mast Cells- Connective tissue cells that releases histamine in allergic reactions 5. Chronic Inflammation- Slow progressive inflammation of connective tissue, usually causes permanent damage 6. Macrophages- Large phagocytic cell derived from a monocyte that ingests microbes 7. Cytokines- Type of protein secreted by a lymphocyte that attacks viruses, virally infected cells and cancer cells 8. Natural Killer Cells- Lymphocyte that causes an infected or cancerous cell to burst 9. Interferon- Antiviral agent produced by an infected cell that blocks the infection of another cell

NONSPECIFIC DEFENSES Nonspecific defenses occur automatically because they are innate; however, no memory is involved—there is no recognition that the same intruder has been attacked before. Barriers to entry, the inflammatory response, phagocytes and natural killer cells and protective proteins are types of nonspecific defenses

Cell-mediated immunity Named for the action of T-cells that directly attack diseased cells and cancer cells. Other T-cells release cytokines that stimulate both nonspecific and specific defenses. T-cells are formed in red bone marrow before they migrate to the tymus, a gland that secretes thymic hormones These hormones stimulate T-cells to develop T-cell receptors

Types of T-cells Cytotoxic—They have storage vacuoles containing perforins and enzymes called granzymes Helper- Help coordinate specific and nonspecific defenses Memory- Remember former antigens

WHAT’S IT LOOK LIKE?  Macrophage  Mast Cell  Natural Killer Cell attacking a Cancer Cell