Will consume hundreds of cells before dying Natural Killer (NK) cells ○ From lymphocytes ○ Nonphagocytic large granular lymphocytes ○ Attack cells that lack “self” cell-surface receptors - Induce apoptosis in cancer cells and virus-infected cells ○ Enhance inflammatory response Antibacterial Proteins ○ Interferons, complement proteins, defensins ○ Attack microorganisms’ ability to reproduce Fever ● Systematic increase in body temperature ○ Result: increase “classic” definition of metabolism ○ By making the body temp higher, chemical reactions speed up ● Leukocytes and macrophages exposed to foreign substances secrete pyrogens Inflammatory Response ● Triggered by: ○ Injured body tissues ○ Extreme heat ○ Infections
● Goals: ○ Prevents spread of damaging agents ○ Disposes of cell debris and pathogens ○ Alerts adaptive immune system ○ Sets the stage for repair Signs of Inflammatory Response 1. Redness 2. Heat 3. Swelling 4. Pain 5. (sometimes) Impairment of function Steps of Inflammation Part 1 ○ Injured/stressed tissue or immune cells release chemical signal ● Example: Leukocytosis-inducing factor; mast cells → histamine ○ Macrophages identify invaders → chemical signal ● Start pathway to combat invaders ○ Vessel dilate ● Redness and heat ● Vasodilation, blood vessel increase in size. Increasing blood flow near site of injury ● Blood flows faster ○ Histamine → higher capillary permeability → exudate enters tissues (exudation) → swelling (edema) → pain ● Function impaired? Steps of Inflammation Part 2 Phagocyte Mobilization ● Phagocytes arrive in mass ○ 1. Neutrophils 3. Diapedesis ○ 2. Macrophages 4. Chemotaxis
○ Neutrophils are the most abundant so they arrive first to the region ○ Leukocytosis : increases white blood cell count to fight off pathogens ○ Chemical marker near wall of injury, where neutrophils will cling to ○ Diapedesis is where neutrophils flatten and squeeze capillaries ○ Lastly, Chemotaxis Neutrophils follow chemical trail Recall - Part of Inflammation ● Histamine → higher capillary permeability → exudate enters tissues (exudation) → swelling (edema) → pain Off to the Lymphatic System ● Exudation → rush of self and foreign material into lymphatic vessels Lymphatic system (to be cleaned) ○ Fluid leaked from blood vessels → back to blood ○ Main structures include spleen, thymus, tonsils, and lymph nodes ● Consists of three parts 1. Network of lymphatic vessels (lymphatics) 2. Lymph - fluid in vessels 3. Lymph nodes - cleanse lymph (1-25mm) Lymphoid cells ● Lymphocytes ○ Arise in red bone marrow ● Mature into one of two main varieties ○ T cells (T lymphocytes) ○ B cells (B lymphocytes) ● Other cells of lymphatic system ○ Macrophages ○ Dendritic cells ○ Reticular cells produce reticular fiber Cancer and Lymphatic System ● TNM system ○ Tumor ○ Nodes ○ Metastasis ● Breast cancer is spread through the body easier because the cancer is right near lots of lymphatic vessels Increase diameter → decrease resistance Increase in resistance → decrease in flow
Immunology part 3 Adaptive defences: Specific/Acquired 9/18
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