Daily Warm-up March 19 th

1. Daily Warm-up March 19th During the Quarter Quell, Katniss Everdeen searches for water in the arena. Before she found it, she began to become dehydrated. What would happen because of this in terms of ADH? How would this help her condition? HW: -Read 35.1 Turn in: -Nothing

2. Animals and Immune Systems • Animals are the only organisms with major immune systems • Help defend against pathogens= disease-causing agents • Ex. Bacteria, fungi, protists, viruses • 2 major components • Innate immunity • Adaptive immunity • Response to specific pathogens • Both ways require molecular recognition

3. Innate Immunity • Found in all animals and plants • Invertebrates • Hard exoskeleton in insects • Immune cells- phagocytosis

5. Innate Immunity of Vertebrates • Barrier Defenses (external) • Skin • Mucous membranes • Other body secretions • Ex. Lysozyme • Acidic environment of stomach • Ciliated epithelia

6. Innate Immunity of Vertebrates Continued • Cellular Innate Defenses (internal) • Phagocytic cells • Macrophages • Natural killer cells • Release chemicals • Lymphatic system helps

7. Innate Immunity Continued • Pathogen presence triggers polypeptide and protein production • Interferons- proteins that help with viral infections • Complement System -Proteins in plasma that can lead to lysis of invading cells

8. Innate Immunity Continued • Inflammatory response • Signaling molecules released upon injury or infection • Swelling and pain • Molecules (cytokines and histamine) to increase blood flow to site of injury or infection *Fever

9. Daily Warm-up March 20th What is one example of innate immunity? HW: -Read 35.2 Turn in: -Nothing

10. Adaptive Immunity • Pathogen-specific recognition • Relies on T cells and B cells • White blood cells known as lymphocytes • Anything that brings about response from the cells is known as an antigen • Usually proteins or polysaccharides • Pathogen recognition is done by an antigen receptor on T and B cells

11. Antigen Recognition by B cells and Antibodies • B cells have membrane-bound antigen receptors • Antibodies- proteins secreted by cells rather than membrane-bound

13. Antigen Recognition by T Cells • T cells bind only to fragments of antigens • MHC molecule- protein on cell that displays fragment of antigen

14. Adaptive Immunity Characteristics • Immense diversity of lymphocytes and receptors • Allow your body to respond to pathogens that have never been encountered • Self-tolerance • Not attack self • Cell proliferation triggered by activation • Increases number of B and T cells specific for an antigen • Stronger and more rapid response to an antigen encountered previously • Immunological memory

15. Generation of B and T Cell Diversity • 1 million different B cell receptors, 10 million T cell • Only 20,000 protein-coding genes • How can this happen?

16. Origin of Self-Tolerance • How does body know self? • Lymphocytes are tested for self-reactivity during development • If have antigen receptors for body, the cell is destroyed

17. Proliferation of B and T cells • Binding of an antigen receptor to an epitope starts events • Activates B cell or T cell • Once activated, begin cellular divisions • Clones are effector cells • B cells= plasma cells which secrete antibodies • T cells= helper T cells and cytotoxic T cells • Memory cells= give rise to effector cells if same antigen is encountered later

19. Immunological Memory • Primary Immune Response • Production of effector cells during first exposure to antigen • Secondary Immune Response • Later exposure • Much faster response (2 days) • Prolonged response • Adaptive!!!

21. Daily Warm-up March 21st What is the difference between B cells and T cells? HW: -Read 35.3

22. 2 Types of Adaptive Immunity • Humoral • Occurs in body fluids • Antibodies eliminate pathogens and toxins • Cell-mediated • T cells destroy infected host cells ***Both can have a primary and secondary immune response ***Both use helper T cells

23. Helper T cells • Trigger both humoral and cell-mediated responses • Release signals that lead to production of antibodies and activate cytotoxic T cells • 2 requirements for helper T cell to activate either response • Foreign molecule must bind to antigen receptor of T cell • Antigen must be displayed on surface of antigen-presenting cell -Ex. B cell or macrophage

24. What is an antigen-presenting cell? • Two classes of MHC molecules • Most cells have only MHC I • Antigen presenting have MHC I and II • Class II provides the correct molecular signature by which a cell is recognized

26. Cell-mediated Response and Cytotoxic T cells • Activated helper T cells can activate cytotoxic T cells • Use toxic proteins (enzymes) to disrupt membrane and trigger cell death

27. B Cells and Antibodies • B cells secrete antibodies in the humoral response • Activation occurs by helper T cells • B cell divides, becoming plasma cells and memory B cells • Antibodies do not kill pathogen directly but marks them and can also inactivate the pathogen • Ex. Virus inactivation

29. Active Immunity vs. Passive Immunity • Active immunity: defenses that arise when a pathogen infects the body • Passive immunity: Antibodies in recipient are produced by another individual • Ex. Fetus and mother • Breast milk and infant • Vaccination/immunization

30. Disruptions in Immune System Regulation • Allergies • Allergens • Trigger release of histamines and inflammatory chemicals

31. Autoimmune Disease • Attack against certain molecules of the body • Ex. Lupus • Antibodies that tag histones and DNA • Ex. Rheumatoid arthritis • More females affected than males • Unknown why this is….