ELAINE N. MARIEB EIGHTH EDITION 12 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART A The Lymphatic System and Body Defenses

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings I. Introduction 1) Without this system our cardiovascular system would stop working and our immune system would be impaired. 2) Consists of lymphatic vessels and various lymphoid tissues and organs. 3) The vessels function to return fluid to the blood 4) The tissue and organs function in the body’s ability to fight diseases

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings II. Lymphatic vessels & Nodes 1) Interstitial fluid: 2) The interstitial fluid must be returned to the blood or the system loses pressure 3) Lymph: 4) Lymphatic capillaries are very permeable with mini-valves allowing fluid to easily enter

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Lymphatic Vessels Figure 12.2

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 5) Problems can occur because viruses, bacteria and cancer cells can enter the vessels and spread 6) Lymph is returned to the blood by the right lymphatic duct and the thoracic duct 7) The system is low-pressure and pumpless. Movement is caused by muscle contractions and pressure changes, with valves preventing back flow.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 12.1

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 8) Lymph nodes a) Function to protect the body by removing foreign material and producing lymphocytes b) As the lymph travels, it is filtered by thousands of nodes (fig. 12.3) c) Macrophages and lymphocytes are located in the nodes to clean the fluid d) If the lymph nodes are swollen 1. if sore probably infection 2. if not sore, possibly cancer

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Lymph Node Structure Figure 12.4

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Lymph Nodes Figure 12.3

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 9) Other organs a) Spleen: 1. filters blood 2. Destroys worn-out RBC 3. Stores platelets and blood 4. Produces lymphocytes b) Thymus: Produces the hormone thymosin that programs certain lymphocytes (t-cells) c) Tonsils: lymphoid tissue in the throat d) Peyer’s patches: along the intestine wall, prevents bacteria from penetrating the wall

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Other Lymphoid Organs Figure 12.5

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings III. Body defenses 1) The body defenses uses 2 methods to fight invaders a) Nonspecific defense system: responds immediately to protect the body from all foreign substances b) Specific defense system (immune system): attack against particular foreign substances 2) Immunity: 3) Both systems work together to protect the body

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Body Defenses Figure 12.6

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings IV. Nonspecific 1) Some nonspecific resistance is inherited (some things we don’t get) 2) The mechanical barriers, cells and chemicals that act initially to protect against pathogens 3) Surface barriers: a) Skin and mucous membranes

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings b) Chemicals produced by membranes 1. Skin: Acid pH & toxic chemicals in sebum 2. Hydrochloric acid and proteases in stomach 3. Lysozyme in saliva and tears 4. Mucus traps microorganisms c) Mucus: trapped in the respiratory tract are moved toward the mouth

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 5) Cells: a) Phagocytes: found in nearly all organs, engulf particles b) NK (natural killer): in blood and lymph, lyse cells, by recognizing sugars on the surface 6) Inflammatory response: a) nonspecific response triggered when tissue is injured

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Defensive Cells Figure 12.7a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings b) 4 signs and symptoms: redness, heat, swelling, and pain c) Histamine & Kinins: chemicals released by injured cells to start inflammation d) These blood vessels dilate and leak (swelling) & activate pain receptors e) Chemotaxis:

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings f) This forces injured areas to rest, prevent spread of invaders, removes debris g) Diapedesis: h) The increased heat increases metabolic rate, speeding up defensive and repair processes

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Steps in the Inflammatory Response Figure 12.8

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 7) Chemicals a) Complement: 20 plasma proteins that become attached to foreign cells 1. MAC (Membrane attack complex): forms lesions, causing cell to burst 2. Amplify inflammatory response 3. Opsonization: causes cell to become sticky and easier to engulf

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Antimicrobial Chemicals Figure 12.10

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings b) Interferon: Virus infected cells release this to help non-infected cells prevent binding of the virus c) Pyrogens: Reset the thermostat causing fever, which causes Fe& Zn to be absorbed by the liver and increases metabolic rate

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings V. Immune system (specific defense) 1) Immune response: increases inflammatory response and targets specific antigens 2) Three important aspects of the immune response: a) antigen specific b) systemic (not restricted to initial infection site) c) Has a memory

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 3) Two parts to the immune response a) Humoral (antibody-mediated): antibodies in the fluids b) Cellular: The lymphocytes are the protective factors 4) Antigen (Ag): a) Any substance that causes an immune response

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings b) Most are large complex molecules not normally present, proteins are the strongest c) As the immune system develops it filters out our own antigens from recognition d) Allergies; small molecules (hapten) combine with cell proteins triggering immune response 5) Cells:

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings a) B cells: develop in the bone marrow and produce antibodies and oversee humoral immunity b) T cells: mature in the thymus and are non-antibody cells involved in cellular immunity c) Macrophages: non-specific defenders that engulf invaders and present antigens to activate T-cells

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 6) Our genes determine what specific substance our immune system will be able to recognize and resist. 7) Humoral response: a) Clonal selection: B-cells mature and multiply rapidly b) Plasma cells: Activated B cells producing antibodies (2000 per sec), last 4-5 days HUMORAL IMMUNITY ANIMATION PRESS TO PLAY

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Humoral Immune Response Figure 12.12

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings c) Memory cells: remain in body for future invasion 8) Immunity: a) The rapid second response to an antigen b) Active immunity: your immune system responds and produces memory cells c) Passive immunity: antibodies are injected

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Secondary Response Figure 12.13

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Active Immunity Figure 12.14

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 9) Antibodies (Igs) a) 5 major classes (pg 409) b) Basic shape: 1. 4 protein chains forming a T or Y shape 2. Variable (V) region: area binding to antigen 3. Constant (C) region: forms the stem of the antibody

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Antibody Structure Figure 12.15b ANTIBODY FUNCTION ANIMATION PRESS TO PLAY

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings c) Function: inactivate antigen by complement fixation, neutralization of toxins, agglutination (clumping) and precipitation 10) Cellular response: a) T-cells also go through clonal selection b) They only bind with antigens presented by macrophages

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Antibody Function Figure 12.16

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings c) Types 1. Cytotoxic (killer) T cells: kill virus infected, cancer or foreign cells by inserting chemicals 2. Helper T cells: recruit other cells to fight invaders, activate T & B cells and enhance macrophages 3. Suppressor T cells: Stop the immune response PRESS TO PLAY CYTOTOXIC T CELLS ANIMATION PRESS TO PLAY HELPER T CELLS ANIMATION

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cellular (Cell-Mediated) Immune Response Figure 12.17

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Summary of the Immune Response Figure 12.19

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings VI. Organ transplants 1) Have had mixed results because of the immune system response causing rejection 2) Major types a) Autografts: from same person b) isografts: same genetic background c) Allografts: unrelated d) Xenografts: different animals

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 3) A 75% match Is needed to attempt a transplant 4) To reduce rejection, the immune system must be suppressed, which increases the chance of infection and death

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Allergy Mechanisms Figure 12.20