Immune System Lectures 26 and 27 1 Blood components a Whole blood i Plasma 55 of whole blood 1 2 Least dense component ii Buffy coat 1 Leukocytes a Defends body against organisms and removes garbage b White blood cells c Lifespan of days to years 2 Platelets a Controls bleeding and generates coagulation b Lifespan of 8 to 11 days 3 1 of whole blood iii Red blood cells Erythrocytes 1 2 45 of whole blood hematocrit 3 Most dense component 4 Shape flexibility and hemoglobin protein help deliver oxygen and other gases 5 Lifespan of 80 to 120 days b White blood cells Leukocytes i True organelles 1 2 Nuclei 3 Protection 4 Granulocytes a Cytoplasmic granules b Lobed nucleus c Neutrophils i Phagocytes d Eosinophils e Basophils Bilobed nucleus Coarse granules stain red Anti parasitic Bilobed nucleus Coarse granules stain blue Release inflammatory mediators 5 Agranulocytes a Lymphocytes b Monocytes Spherical nucleus Adaptive immunity Kidney shaped nucleus Tissue macrophages Phagocyte 1 i ii iii i ii iii i ii i ii ii Mediators of the immune system iii 5 main types Never Let Monkeys Eat Bananas 1 Mnemonic goes from most abundant to least abundant 2 Monocyte macrophages kidney shape nucleus abundant pale blue cytoplasm a 2 8 blue cytoplasm a 20 40 granules a 40 60 a a 1 4 5 1 3 Lymphocytes small large spherical nucleus thin rim of pale 4 Neutrophils multilobed nucleus pale red and blue cytoplasmic 5 Eosinophils bilobed nucleus red cytoplasmic granules 6 Basophils bilobed nucleus purplish black cytoplasmic granules iv Can be measured with differential 1 Gives percentages of white blood cells 2 Blood flow a Capillary blood flow i ii Blood propelled by heart Leaves heart through aorta 1 Arteries arterioles 2 Capillaries 3 Venules veins back to heart b Fluid movement what dictates flow 1 Hydrostatic pressure a Aka blood pressure 2 Osmotic pressure ii In the capillaries i Direction and amount of fluid flow depending on two opposing forces 1 Net filtration pressure NFP comprises all forces acting on capillary bed a NFP HPc OPif HPif OPc 2 Net fluid flow out at arterial end filtration 3 Net fluid flow in at venous end reabsorption a NFP positive a NFP negative 20 liters of fluid filtered out at arteriole end 17 liters of fluid reabsorbed at venous end 1 2 3 3 liters remain behind in tissues a Become part of interstitial fluid iii More fluid leaves at arterial end than is returned at venous end iv v Loss of fluid and proteins can reduce blood volume pressure How is fluid returned to the circulatory system 1 3 Lymphatic system Lymphatic system a Returns excess fluid proteins to cardiovascular system b Composed of i ii Lymphatic vessels lymphatics Lymph fluid in vessels iii Lymph nodes cleanse the lymph c Lymph capillaries i Where lymph transport begins ii Weave between tissue and blood capillaries iii Not found in central nervous system teeth bones or bone marrow d Lymph transport i ii iii iv Multiple trunks drain into a lymphatic duct Extracellular fluid is first collected in lymphatic capillaries Lymphatic capillaries converge into lymphatic vessels Lymphatic vessels unite form lymphatic trunks 1 2 ducts a Right lymphatic duct b Thoracic duct 2 Both empty at junction of jugular and subclavian veins 4 Lymphatics a Lymphatics are made up of i ii iii Lymphoid cells Lymphoid tissues Lymphoid organs 1 Two broad types a Primary lymphoid organs i Where B and T cells develop and mature ii Thymus 1 Where T cells mature iii Bone marrow 1 Where both B and T cells develop 2 Where B cells mature b Secondary lymphoid organs Peripheral lymphoid organs i ii Where mature lymphocytes interact with antigens Spleen Lymph nodes iii iv 1 Two important functions a Filtering lymph i The only secondary lymphoid organ that filters lymph Contains afferent and efferent lymphatics b Acts as a site of interaction ii between antigens and lymphocytes i Activates lymphocytes v MALT vi Diffuse lymphoid tissues 5 Cells a Human body i Eukaryotic 1 Organelles ii Microbiome b Pathogens infectious agents i ii Usually microorganisms Types of pathogens 1 Viruses a AIDS nonliving 2 Prokaryotes a Leprosy 3 Fungi a Athlete s foot 4 Protozoans a Malaria 5 Parasites a Tapeworm c Antigens a substance that can be recognized by the immune system i ii Activates the immune system Causes an immune response 1 The production of antibodies 2 Antibody generator Can be part of a pathogen iii i ii d Epitope a part of an antigen to which an antibody binds Aka antigenic determinant Antigens can have multiple epitopes 1 Pathogens have multiple antigens so LOTS of epitopes 6 The immune system a Composed of two arms i Innate nonspecific 1 Surface barriers a Skin b Mucous membranes 2 Internal defenses a Phagocytes b Natural killer cells c d Antimicrobial proteins e Inflammation Fever ii Adaptive specific a Specific antigen b Systematic throughout body c Memory 2 Humoral immunity 3 Cellular immunity a B cells a T cells iii They are interdependent b Duration i Innate always in place Immediate to hours 1 2 3 Helps active adaptive immunity ii Adaptive 1 Delay lag of a few days 2 Has to be primed 3 Active 4 7 days after infection c Specificity i Innate 1 Microbial patterns 2 Pattern recognition receptors PRRs a Recognize PAMPs ii Adaptive 1 Recognize antigens d Memory i Innate ii Adaptive 1 No memory 2 Response to same pathogen never changes 7 Humoral and innate immunity a Two arms of the adaptive immune system i Humoral immunity 1 B cells antibodies a Extracellular targets i ii iii Viruses Bacteria Bacterial toxins ii Cell mediated immunity 1 T cells a Intracellular targets i ii Viral infected cells Tumor cells b B cells Have transmembrane receptors that bind antigens i ii Membrane bound antibodies 1 Memory 2 Response to same antigen pathogen increases with exposure 1 1 immunoglobulins lgs Secrete antibodies Immunoglobulins Regulate hormonal immunity c Antibodies Y shaped protein 4 polypeptide chains form an antibody 2 antigen binding sites d Light and heavy chains made up of Variable regions 1 Antigen specific regions iii iv i ii iii i a Allow for binding to a specific antigen ii Constant regions 1 Mediate effector functions a Binding to basophils b Interaction with complement e T cells i Mature in thymus ii Regulate cell mediated immunity 1 Provide defense against intracellular pathogens a Cells infected with viruses or bacteria b Cancerous cells iii Bind to peptide antigens 1 Need to be presented by MHC molecules 2 Have T cell receptors iv v Two major