1st Edition BIOL 252 Lecture 16 Outline of Last Lecture I Liver II Adrenal Glands III Lymphatic System IV Lymphatic Vessels and Lymph V Lymphatic tissues Outline of Current Lecture I Lymphatic Organs II Nonspecific Defenses III Specific Defenses Current Lecture I II Lymphatic Organs a Tonsils b Thymus i Where T cells mature c Spleen i Filters blood d Lymph nodes i Where lymphocytes gather to come in contact w pathogens ii Lymph comes from excess interstitial tissue fluid iii Filter lymph Nonspecific Defenses a Difference versus specific i Nonspecific react the same way regardless of what pathogen is b Physical Barriers i Skin 1 Keratinized stratified epithelium 2 Secretions acid mantle dermicidin ii Mucous membranes 1 Acid mucus lysozyme breaks down bacteria iii Beyond the epithelium 1 Hyaluronic acid viscous component of ECM c Leukocytes white blood cells and macrophages These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute i Made in red bone marrow ii Phagocytes 1 Macrophages big cells phage engulfs work in part by engulfing bacteria 2 Neutrophils and eosinophils engulf pathogens through phagocytosis iii Basophils mast cells 1 Signal to phagocytes and lymphocytes 2 Blood cell basophil 3 Mast cell connective tissue cell 4 Release hormones and attract other cells to site of injury or injection a By dilating or hemo attraction release chemicals 5 Histamine vasodilator 6 Leukotrienes attract leukocytes 7 Heparin anticoagulant d Natural killer cells i Non selective lymphocytes that destroy cancerous or infected cells ii Releases perforins pokes holes in cell membrane iii Releases granzymes that flow through pores and kill cell iv Cells die by apoptosis v Present in blood lymph lymphatic tissue organs e Defensive proteins i Interferons newly infected cells send warning message to neighbors response includes antiviral proteins AVPs ii Limits infection rather than stopping it iii Complement 1 Lyse bacteria through formation of pore complexes part of nonspecific 2 Label bacteria for destruction by antibodies part of specific response 3 Enhance inflammatory response 4 Work with antibodies hence complement f Inflammation i Signs swelling heat redness pain itchiness ii Result of inflammatory response iii Inflammatory chemicals cause RBC to move into area g Fever i Raise in body s temperature ii Hypothalamus in charge and keeps body temperature hovering around 37C iii Infection and pyrogen secretion hypothalamic thermostat is reset to higher set point III 1 Benefits chemical reactions go faster 2 iv Onset body temperature rises v Body temperature oscillates around new set point vi Infection ends set point returns to normal body temp returns Specific Defenses a Includes T and B cells antigen presenting cells b T cells i Cytotoxic CD8 1 Cell killers ii Helper CD4 1 Facilitate Tc cell and B cell activation iii Regulatory T cells 1 Terminate immune response iv Memory T cells 1 Descend from activated Tc responsible for memory in cellular immunity c Can potentially respond to anything d Make T cells in bone barrow e Travel to thymus through the blood i Learn self tolerance and immunocompetence ii Self tolerance do not attack yourself only virus infected you iii Get rid of one s that are not self tolerant iv Immunocompetence ability to function in the immune system 1 Ability to respond to MHC major histocompatibility complex on antigen presenting cells v Somehow a T cell never makes it to the thymus and grows up happily in the spleen Which is a consequence of this scenario 1 T cell will be able to bind MHC but not recognize foreign antigens 2 T cell will be able to bind MHC and recognize foreign antigens 3 Answer T cell will be unable to bind MHC but not recognize foreign antigens a If we go to thymus come out with ONLY Immunocompetent cells b If it doesn t go to the thymus we can t conclude anything i Mixture of both Immunocompetent and not