Exam III Study Guide PET3323C Mia Newlin Spring 2012 Spleen filters blood storage site for red blood cells Thymus active in early childhood site for T lymphocyte maturation T cells gain immune competence here activity declines after childhood Lymphatic System Tonsils partially capsulated structures containing lymphoid follicles exposed to pathogens early Simplest lymphoid organs palatine tonsils typically the ones that are removed lingual tonsils pharyngeal tonsils tubal tonsils Dip in tonsils contains mostly lymphoid follicles helps to bring pathogens further in to present to immune cells Peyers Patches clusters of lymphoid follicles diffused lymphatic tissue contained in sites exposed to pathogens early The Immune System Made up of 2 intrinsic defense systems that independently and cooperatively provide resistance to disease Innate nonspecific unaware of constantly battling invaders o 1st and 2nd line of defense Adaptive specific attack specific cells to fight specific antigens o 3rd line of defense causes things we are aware of like swollen lymph nodes etc Exam III Study Guide PET3323C Mia Newlin Spring 2012 Innate Defense System Surface barriers 1st defense Mucous membranes Skin keratinized epithelial membrane resistant to weak acids bases toxins o Acidic skin secretions pH 3 5 o Acidic stomach secretions HCl and protein digesting enzymes o Saliva lacrimal fluid saliva salivary amylase for digestion of carbohydrates lacrimal fluid lysozymes for digestion of proteins o Mucus traps microorganisms o Vaginal secretions low pH Cellular Chemical Defense 2nd defense Phagocytes macrophages primary phagocytic cells neutrophils most abundant o Pus dead macrophages neutrophils the cellular debris they ve created Natural Killer Cells migrate attack foreign invaders Fever Antimicrobial proteins complete interferons Phagocytes Phagocytosis steps 1 Pathogen debris adhered to phagocytic cell 2 Cell engulfs pathogen debris forming phagosome 3 Lysosome binds to phagosome releases digestive enzymes into vesicle forming phagolysosome 4 Exocytosis of vesicle removes indigestible residual material from cell Opsonization makes pathogen more able to adhere to phagocytic cell Chemotaxis injured tissues send out chemical signals to attract white blood cells to site of injury Respiratory burst production of free radicals to cause more digestion enhances killing mechanism Natural Killer Cells Lyse infected cells before the adaptive immune system is activated first response Large granular lymphocytes granules contain poriferans and granzymes o Poriferans poke holes in target cell intracellular fluids rush in cell explodes o Granzymes initiate apoptosis cell death Non specific cells that attack non self cells Secrete chemicals that enhance the inflammatory response Inflammatory Response Tissue injury causes 1 Release of chemical mediators histamine compliment kinans prostaglandins causing a Vasodilation of arterioles blood cells open up rush of blood local hyperemia causes redness heat increased blood flow also increases O2 and nutrients to area i Increased temperature increases metabolic rate of cells healing Increased capillary permeability more fluid to site of infection capillaries leak fluid proteins b Exam III Study Guide PET3323C Mia Newlin Spring 2012 i Leaked protein rich fluid in tissue spaces causes swelling pain possible limitation of moving is a protective effect due to swelling ii Leaked clotting proteins causes clotting factors to commence the coagulation response we learned about last exam c Chemotaxis attraction of neutrophils monocytes and lymphocytes to site of injury causes pain 2 Leukocytosis attracts white blood cells to infected area phagocyte mobilization occurs contributing to repair of injured area this chart is a good way to memorize the inflammatory response If you get the gist of this you ll understand the material Exam III Study Guide PET3323C Mia Newlin Spring 2012 Phagocytic Mobilization Leukocytosis neutrophils enter blood from bone marrow Margination neutrophils cling to capillary walls Diapedesis phagocytic cells flatten squeeze through capillary walls o Leaky capillaries make this response easier Chemotaxis neutrophils follow chemical trail towards bacterial factors Antimicrobial Proteins Proteins activated by signals systematically or spontaneously activated Interferons secreted by cells infected by viruses o Prevent viral replication cells can t help themselves so they secrete proteins to help other cells interfere with viral replication o Gamma interferons secreted by lymphocytes enhances T cell activity o Alpha interferons secreted by most leukocytes except lymphocytes reduces inflammation o Beta interferons secreted by fibroblasts reduces inflammation Complement cascade activation of proteins domino effect o Acts like phagocytic cells causes cells to destroy themselves insertion of MAC forms a hole in the cell membrane and induces lysis of the cell MAC membrane attack complex o Enhances inflammation response histamine release increased blood vessel permeability chemotaxis enhances opsonization enhances phagocytosis o 2 pathways classical and alternative Fever increases metabolic rate of cells to aid in killing target cells Elevated body temperature response to invading organisms o A low grade fever up to a specific point is beneficial Body thermostat heated upwards by pyrogens secreted by leukocytes and macrophages exposed to bacteria and other microbes after the thermostat is set back to normal body tries to rid the body of that extra heat o Elevated temperatures intensify interferon effects inhibits growth of microbes and speeds up the bodily repair process o Too high temp starts to denature proteins Adaptive specific Defenses Antigen specific attacks directed towards specific antigen systematic not restricted to initial infected site cells go everywhere throughout the body has memory after initial exposure it recognizes and mounts even stronger attacks on the previously encountered pathogen quicker effective attack Exam III Study Guide PET3323C Mia Newlin Spring 2012 These characteristics are not evident in nonspecific defenses Immunity 2 types Humoral anti body mediated antibodies travel through body humors and bind to bacteria toxins and free viruses Cellular cell mediated t lymphocytes attack virus or parasite infected cells and cancer cells Helper t cells are involved in both responses Complete Antigens Have 2 important properties Immunogenicity ability to
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