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BIOL110s05-40 - BIOL 110 Principles of Biology Spring 2005...

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Unformatted text preview: BIOL 110: Principles of Biology Spring 2005 Lecture 40, M 5/9/05 http://www.smccd.net/accounts/staplesn/biol110/ • Quiz #7 (Last Quiz!): up ~Today – (microbes, plants, animal Tissues & homeostasis). – http://smcwebtest.smccd.net/accounts/staplesn/index.tpx • Extra Credit: Stanford Talk, and 2nd Journal Article due Wed, 5/11. NO Late E.C. will be accepted!!! • Midterm 3 (if <70%), Rewrite/Extra Credit due by Fri., 5/13. • TODAY & WED. Field Trip: Edgewood Park (@ 280 & Edgewood Road) Edgewood – Grade for participation & Worksheet!!! (Replace 1 quiz!!!) – Bring: Good shoes/boots, light-colored clothing/pants, notepad & lightworksheet, binoculars?, hat, sunblock, water, snack? worksheet – Mon.: Meet at Old Stage Camp entrance, 1:10pm. We leave up the Sylvan Trail at 1:20pm. – Wed.: Meet at 8:10am, leave at 8:20am. DON’T BE LATE! DON’ • Maps, info: www.friendsofedgewood.org • Next: Ch. 25, 23, 29 & 30, (31, 32). Meet Here!! 1 REVIEW: • Ch. 25: Nervous System [& Senses] – Nerve synapse, neurotransmitters – Reflex arcs – Central and peripheral nervous systems • Ch. 23: Immunity TODAY: • Ch. 23: Immunity Immunity Chapter 23 Macrophage HIV-infected T-cell HIVT- 2 Edward Jenner’s Experiment • Injected material from a cowpox sore into arm of healthy boy • Six weeks later, injected material from smallpox sores • Boy remained healthy • French called Jenner’s procedure vaccination vaccination – means “encowment” Louis Pasteur • Developed immunization procedures for other pathogens • Called them vaccinations in Jenner’s vaccinations honor 3 I. Three Lines of Defense • Barriers at body surfaces • Nonspecific responses • Immune responses A. Barriers at Body Surface 1. Intact skin and mucous membranes skin mucous • Tough, salty, low pH, antibiotics/enzymes….. antibiotics/enzymes… 2. Lysozyme – destroys bacterial cell wall 3. Normal bacterial flora – block attachment by other, virulent, microbes 4. Flushing effect and low pH of urine 4 B. Nonspecific Responses • Lymph nodes trap and kill pathogens – Phagocytes: macrophages, neutrophils, dendritic cells • Natural killer cells attack a range of targets • Inflammation II. Complement System • Plasma proteins (~20) that take part in both specific and nonspecific response • Activation of one triggers cascade of reactions that activate others Indirect Activation (Ab / Ig) (Ab Ig) antibodies activated complement one membrane attack complex (cutaway view) lipid bilayer of one kind of pathogen activated complement Direct Activation activated complement bacterial pathogen ACTIVATION CASCADE REACTION FORMATION OF ATTACK COMPLEXES LYSIS OF TARGET 5 III. Acute Inflammation • Nonspecific response to foreign invasion, tissue damage, or both • Destroys invaders, removes debris, and prepares area for healing • Characterized by redness, swelling, warmth, and pain Inflammation Inflammation 4. 1. 5. 2. 3. 1. Invading bacteria damage tissue 1. 2. Mast cells release histamine 3. Capillaries dilate and leak – (swell, red, warm, pain) 4. Complement proteins attack bacteria 5. White cells attack invaders and clean up 6 IV. Immune Responses (to specific damage or invaders) specific • Directed against specific invaders • Carried out by T cells, B cells, cells cells macrophages** & NK cells** • Communication signals such as interleukins play a vital role interleukins A. Features of Immune System • Self / Nonself recognition • Diversity • Immunological specificity – B and T cells zero in on certain kinds of pathogens; – response is pathogen-specific pathogen- • Immunological memory – Immune system recognizes and reacts swiftly to a pathogen it has “seen” seen” 7 Memory and Effector Cells • When a B or T cell is stimulated to divide, it produces more than one cell type • Memory cells are set aside for future use; they are the basis for immune memory • Effector cells engage and destroy the current threat Macrophage B. Key Components of Immune Response 1. MHC markers = “tags” that sound the “alarm” 2. Antigen-presenting cells (APCs) = “scouts” – B cells – Dendritic cells - executioners – Macrophages – marching soldiers & executioners – ….many other cells of the body…. body… • Helper T cells (Th) = “buglers” rally the troops! • Effector cytoxic T cells (Tc) = “skilled swordsmen” • Natural killer cells (NK) = “frontline swordsmen” • B cells = “archers and taggers” 8 NK cells?? eosinophils neutrophils basophils T mast cells lymphocytes lymphocytes (mature in bone marrow) (mature in thymus) B forerunners of the white blood cells (leukocytes) ? stem cells that multiply and differentiate in bone marrow monocytes (immature phagocytes) red blood cells (erythrocytes) mature macrophages dendritic cells megakaryocytes platelets Ch. 22 Overview of Interactions Antibody - mediated response Cell - mediated response Naive B cell Antigenpresenting cell (APC) Naive helper T cell Effector B cell (plasma cell) interleukins interleukins Naive cytotoxic T cell Activated helper T cell Effector cytotoxic T cell 9 Phagocytosis and Antigen Presentation Inside APC antigen framents MHC molecule antigen-MHC complex Fig. 35.6, p. 582 C. B Cell Formation • Derived from stem cells in bone marrow • Acquire unique antigen-binding receptors in marrow • Receptors interact with just one antigen • Exposure to that antigen causes clonal clonal selection – Division of cells specific for that antigen 10 Clonal Selection of a B Cell • Only the B cell with antigen-receptor that matches antigen is stimulated to divide B1 B2 B3 antigen binds only to antibody specific to it on a naïve B cell. naï antigen • Mitosis yields many cells with that receptor B2 B2 B2 B2 Clonal population of effector B cells Clonal effector B cells secrete the SAME SPECIFIC antibody D. Immunological Memory Memory cells specific for an antigen • are quickly activated to divide • upon subsequent exposure to that antigen Primary Immune Primary Response: naive T or B cell effector cells memory cells Secondary Immune Response: effector cells memory cells Figure 23.6 Figure Page 394 11 ...
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