1. Essentials of Human Anatomy & Physiology Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slides 12.1 – 12.22 Seventh Edition Elaine N. Marieb Chapter 12 The Lymphatic System and Body Defenses Lecture Slides in PowerPoint by Jerry L. Cook

2. The Lymphatic System Slide 12.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Consists of two semi-independent parts  Lymphatic vessels  Lymphoid tissues and organs  Lymphatic system functions  Transport fluids back to the blood  Play essential roles in body defense and resistance to disease

3. Lymphatic Characteristics Slide 12.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymph – excess tissue fluid carried by lymphatic vessels  Properties of lymphatic vessels  One way system toward the heart  No pump  Lymph moves toward the heart  Milking action of skeletal muscle  Rhythmic contraction of smooth muscle in vessel walls

4. Lymphatic Vessels Slide 12.3a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymph Capillaries  Walls overlap to form flap-like minivalves  Fluid leaks into lymph capillaries  Capillaries are anchored to connective tissue by filaments  Higher pressure on the inside closes minivalves

5. Lymphatic Vessels Slide 12.3b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.1

6. Lymphatic Vessels Slide 12.4a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymphatic collecting vessels  Collects lymph from lymph capillaries  Carries lymph to and away from lymph nodes Figure 12.2

7. Lymphatic Vessels Slide 12.4b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymphatic collecting vessels (continued)  Returns fluid to circulatory veins near the heart  Right lymphatic duct  Thoracic duct Figure 12.2

8. Lymph Slide 12.5a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Materials returned to the blood  Water  Blood cells  Proteins

9. Lymph Slide 12.5b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Harmful materials that enter lymph vessels  Bacteria  Viruses  Cancer cells  Cell debris

10. Lymph Nodes Slide 12.6a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Filter lymph before it is returned to the blood  Defense cells within lymph nodes  Macrophages – engulf and destroy foreign substances  Lymphocytes – provide immune response to antigens

11. Lymph Nodes Slide 12.6b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.3

12. Lymph Node Structure Slide 12.7a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Most are kidney-shaped, less than 1 inch long  Cortex  Outer part  Contains follicles – collections of lymphocytes  Medulla  Inner part  Contains phagocytic macrophages

13. Other Lymphoid Organs Slide 12.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Several other organs contribute to lymphatic function  Spleen  Thymus  Tonsils  Peyer’s patches Figure 12.5

14. The Spleen Slide 12.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Located on the left side of the abdomen  Filters blood  Destroys worn out blood cells  Forms blood cells in the fetus  Acts as a blood reservoir

15. The Thymus Slide 12.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Located low in the throat, overlying the heart  Functions at peak levels only during childhood  Produces hormones (like thymosin) to program lymphocytes

16. Tonsils Slide 12.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Small masses of lymphoid tissue around the pharynx  Trap and remove bacteria and other foreign materials  Tonsillitis is caused by congestion with bacteria

17. Peyer’s Patches Slide 12.13 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Found in the wall of the small intestine  Resemble tonsils in structure  Capture and destroy bacteria in the intestine

18. Mucosa-Associated Lymphatic Tissue (MALT) Slide 12.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Includes:  Peyer’s patches  Tonsils  Other small accumulations of lymphoid tissue  Acts as a sentinal to protect respiratory and digestive tracts

19. Body Defenses Slide 12.15a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The body is constantly in contact with bacteria, fungi, and viruses  The body has two defense systems for foreign materials  Nonspecific defense system  Mechanisms protect against a variety of invaders  Responds immediately to protect body from foreign materials

20. Body Defenses Slide 12.15b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Specific defense system  Specific defense is required for each type of invader  Also known as the immune system

21. Nonspecific Body Defenses Slide 12.16 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Body surface coverings  Intact skin  Mucous membranes  Specialized human cells  Chemicals produced by the body

22. Surface Membrane Barriers – First Line of Defense Slide 12.17a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The skin  Physical barrier to foreign materials  pH of the skin is acidic to inhibit bacterial growth  Sebum is toxic to bacteria  Vaginal secretions are very acidic

23. Surface Membrane Barriers – First Line of Defense Slide 12.17b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Stomach mucosa  Secretes hydrochloric acid  Has protein-digesting enzymes  Saliva and lacrimal fluid contain lysozyme  Mucus traps microogranisms in digestive and respiratory pathways

24. Defensive Cells Slide 12.18a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Phagocytes (neutrophils and macrophages)  Engulfs foreign material into a vacuole  Enzymes from lysosomes digest the material Figure 12.6b

25. Defensive Cells Slide 12.18b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Natural killer cells  Can lyse and kill cancer cells  Can destroy virus- infected cells Figure 12.6b

26. Inflammatory Response - Second Line of Defense Slide 12.19 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Triggered when body tissues are injured  Produces four cardinal signs  Redness  Heat  Swelling  Pain  Results in a chain of events leading to protection and healing

27. Functions of the Inflammatory Response Slide 12.20 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Prevents spread of damaging agents  Disposes of cell debris and pathogens  Sets the stage for repair

28. Steps in the Inflammatory Response Slide 12.21 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.7

29. Antimicrobial Chemicals Slide 12.22c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Interferon  Secreted proteins of virus-infected cells  Bind to healthy cell surfaces to inhibit viruses binding

30. Fever Slide 12.23 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Abnormally high body temperature  Hypothalmus heat regulation can be reset by pyrogens (secreted by white blood cells)  High temperatures inhibit the release of iron and zinc from liver and spleen needed by bacteria  Fever also increases the speed of tissue repair

31. Specific Defense: The Immune System – Third Line of Defense Slide 12.24 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Antigen specific – recognizes and acts against particular foreign substances  Systemic – not restricted to the initial infection site  Has memory – recognizes and mounts a stronger attack on previously encountered pathogens

32. Types of Immunity Slide 12.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Humoral immunity  Antibody-mediated immunity  Cells produce chemicals for defense  Cellular immunity  Cell-mediated immunity  Cells target virus infected cells

33. Allergies Slide 12.28 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Many small molecules (called haptens or incomplete antigens) are not antigenic, but link up with our own proteins  The immune system may recognize and respond to a protein-hapten combination  The immune response is harmful rather than protective because it attacks our own cells

34. Cells of the Immune System Slide 12.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lymphocytes  Originate from hemocytoblasts in the red bone marrow  B lymphocytes become immunocompetent in the bone marrow  T lymphocytes become immunocompetent in the thymus  Macrophages  Arise from monocytes  Become widely distributed in lymphoid organs

35. Activation of Lymphocytes Slide 12.30 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.9

36. Humoral (Antibody-Mediated) Immune Response Slide 12.31a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  B lymphocytes with specific receptors bind to a specific antigen  The binding event activates the lymphocyte to undergo clonal selection  A large number of clones are produced (primary humoral response)

37. Humoral (Antibody Mediated) Immune Response Slide 12.31b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Most B cells become plasma cells  Produce antibodies to destroy antigens  Activity lasts for four or five days  Some B cells become long-lived memory cells (secondary humoral response)

38. Humoral Immune Response Slide 12.32 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.10

39. Secondary Response Slide 12.33 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Memory cells are long-lived  A second exposure causes a rapid response  The secondary response is stronger and longer lasting Figure 12.11

40. Active Immunity Slide 12.34 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Your B cells encounter antigens and produce antibodies  Active immunity can be naturally or artificially acquired Figure 12.12

41. Passive Immunity Slide 12.35 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Antibodies are obtained from someone else  Conferred naturally from a mother to her fetus  Conferred artificially from immune serum or gamma globulin  Immunological memory does not occur  Protection provided by “borrowed antibodies”

42. Monoclonal Antibodies Slide 12.36 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Antibodies prepared for clinical testing or diagnostic services  Produced from descendents of a single cell line  Examples of uses for monoclonal antibodies  Diagnosis of pregnancy  Treatment after exposure to hepatitis and rabies

43. Antibodies (Immunoglobulins) (Igs) Slide 12.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Soluble proteins secreted by B cells (plasma cells)  Carried in blood plasma  Capable of binding specifically to an antigen

44. Antibody Structure Slide 12.38a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Four amino acid chains linked by disulfide bonds  Two identical amino acid chains are linked to form a heavy chain Figure 12.13b

45. Antibody Structure Slide 12.38b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The other two identical chains are light chains  Specific antigen- binding sites are present Figure 12.13b

46. Antibody Classes Slide 12.39 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Antibodies of each class have slightly different roles  Five major immunoglobulin classes  IgM – can fix complement  IgA – found mainly in mucus  IgD – important in activation of B cell  IgG – can cross the placental barrier  IgE – involved in allergies

47. Cellular (Cell-Mediated) Immune Response Slide 12.42 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Antigens must be presented by macrophages to an immunocompetent T cell (antigen presentation)  T cells must recognize nonself and self (double recognition)  After antigen binding, clones form as with B cells, but different classes of cells are produced

48. T Cell Clones Slide 12.44a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cytotoxic T cells  Specialize in killing infected cells  Insert a toxic chemical (perforin)  Helper T cells  Recruit other cells to fight the invaders  Interact directly with B cells

49. T Cell Clones Slide 12.44b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Suppressor T cells  Release chemicals to suppress the activity of T and B cells  Stop the immune response to prevent uncontrolled activity  A few members of each clone are memory cells

50. Organ Transplants and Rejection Slide 12.46a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Major types of grafts  Autografts – tissue transplanted from one site to another on the same person  Isografts – tissue grafts from an identical person (identical twin)  Allografts – tissue taken from an unrelated person  Xenografts – tissue taken from a different animal species

51. Organ Transplants and Rejection Slide 12.46b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Autografts and isografts are ideal donors  Xenografts are never successful  Allografts are more successful with a closer tissue match

52. Disorders of Immunity: Allergies (Hypersensitivity) Slide 12.47a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Abnormal, vigorous immune responses  Types of allergies  Immediate hypersensitivity  Triggered by release of histamine from IgE binding to mast cells  Reactions begin within seconds of contact with allergen  Anaphylactic shock – dangerous, systemic response

53. Disorders of Immunity: Allergies (Hypersensitivity) Slide 12.47b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Types of allergies (continued)  Delayed hypersensitivity  Triggered by the release of lymphokines from activated helper T cells  Symptoms usually appear 1–3 days after contact with antigen

54. Allergy Mechanisms Slide 12.48 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 12.17

55. Disorders of Immunity: Immunodeficiencies Slide 12.49 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Production or function of immune cells or complement is abnormal  May be congenital or acquired  Includes AIDS – Acquired Immune Deficiency Syndrome

56. Disorders of Immunity: Autoimmune Diseases Slide 12.50a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The immune system does not distinguish between self and nonself  The body produces antibodies and sensitized T lymphocytes that attack its own tissues

57. Disorders of Immunity: Autoimmune Diseases Slide 12.50b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Examples of autoimmune diseases  Multiple sclerosis – white matter of brain and spinal cord are destroyed  Myasthenia gravis – impairs communication between nerves and skeletal muscles  Juvenile diabetes – destroys pancreatic beta cells that produce insulin  Rheumatoid arthritis – destroys joints

58. Disorders of Immunity: Autoimmune Diseases Slide 12.50c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Examples of autoimmune diseases (continued)  Systemic lupus erythematosus (SLE) – affects kidney, heart, lung and skin  Glomerulonephritis – impairment of renal function

59. Self Tolerance Breakdown Slide 12.51a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Inefficient lymphocyte programming  Appearance of self-proteins in the circulation that have not been exposed to the immune system  Eggs  Sperm  Eye lens

60. Self Tolerance Breakdown Slide 12.51b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cross-reaction of antibodies produced against foreign antigens with self- antigens  Rheumatic fever

61. Developmental Aspects of the Lymphatic System and Body Defenses Slide 12.52 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Except for thymus and spleen, the lymphoid organs are poorly developed before birth  A newborn has no functioning lymphocytes at birth; only passive immunity from the mother  If lymphatics are removed or lost, severe edema results, but vessels grow back in time