1. Chapter 12 The Lymphatic System and Body Defenses
Anatomy & Physiology
Chapter 12 The Lymphatic System and Body Defenses

2. Warm-up 05/18
What are the active and passive examples of naturally acquired immunity?
What are the active and passive examples of artificially acquired immunity?

3. Active and Passive Immunity

4. Agenda 05/18 Finish Humoral Immune Response
Antibodies, Immunoglobulin types, functions
Cellular (Cell-Mediated) Immune Response
T-Cells
Operation Antibody p.28

5. Monoclonal Antibodies
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

6. Antibodies (Immunoglobulins) (Igs)
Soluble proteins secreted by B cells (plasma cells)
Carried in blood plasma
Capable of binding specifically to an antigen

7. Antibody Structure Four amino acid chains linked by disulfide bonds
Two identical amino acid chains are linked to form a heavy chain

8. Antibody Structure The other two identical chains are light chains
Specific antigen-binding sites are present

9. Antibody Classes
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

10. Antibody Function Antibodies inactivate antigens in a number of ways
Complement fixation
Neutralization
Agglutination
Precipitation

11. Antibody Function

12. Cellular (Cell-Mediated) Immune Response
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

13. Cellular (Cell-Mediated) Immune Response

14. T Cell Clones Cytotoxic T cells Helper 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

15. T Cell Clones 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

16. Summary

17. Operation Antibody p.28 In your small groups: Homework
Follow directions for your assigned case.
Write a script and be ready to perform for the class tomorrow.
EXTRA CREDIT: RECORD YOUR SKIT ON A FLIP CAMERA (in the form of a movie)
Homework
Packet pps. 3-4, 8-19 Due Thursday
Packet pps Due Friday

18. Warm-up 05/16
Why do you get a fever when you are sick?

19. Agenda 05/16 First and Second Lines of Defense
Intro to Chapter 12 Independent Project
Due Monday May 30th
Miracle of the Immune System

20. Body Defenses
The body is constantly in contact with bacteria, fungi, and viruses
The body has two defense systems for foreign materials
Nonspecific defense system
Specific defense system
Also known as the immune system

21. Nonspecific Body Defenses
Body surface coverings
Intact skin
Mucous membranes
Specialized human cells
Chemicals produced by the body

22. Surface Membrane Barriers – First Line of Defense
The skin
Physical barrier to foreign materials
pH of the skin is acidic to inhibit bacterial growth

23. Surface Membrane Barriers – First Line of Defense
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 Phagocytes (neutrophils and macrophages)
Engulfs foreign material into a vacuole
Enzymes from lysosomes digest the material

25. Defensive Cells Natural killer cells Can lyse and kill cancer cells
Can destroy virus- infected cells

26. Inflammatory Response - Second Line of Defense
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
Prevents spread of damaging agents
Disposes of cell debris and pathogens
Sets the stage for repair

28. Steps in the Inflammatory Response

29. Antimicrobial Chemicals
Complement
Activated when they encounter and attach to cells (complement fixation)
Damage foreign cell surfaces

30. Antimicrobial Chemicals
Interferon
Secreted proteins of virus-infected cells
Bind to healthy cell surfaces to inhibit viruses binding

31. Fever 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

32. Warm-up 05/17
What are the four symptoms produced by the healing process?
Redness
Heat
Pain
Swelling

33. Agenda 05/17 Third Line of Defense – THE IMMUNE SYSTEM
Humoral immunity
Cellular immunity
Classwork/Homework Due Thursday
Packet pps. 3-4, 8-19

34. Specific Defense: The Immune System – Third Line of Defense
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

35. Types of Immunity Humoral immunity Cellular immunity
Antibody-mediated immunity
Cells produce chemicals for defense
Cellular immunity
Cell-mediated immunity
Cells target virus infected cells

36. Antigens (Nonself)
Any substance capable of exciting the immune system and provoking an immune response
Examples of common antigens
Foreign proteins
Nucleic acids
Large carbohydrates
Some lipids
Pollen grains
Microorganisms

37. Self-Antigens Human cells have many surface proteins
Our immune cells do not attack our own proteins
Our cells in another person’s body can trigger an immune response because they are foreign
Restricts donors for transplants

38. Allergies
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

39. Cells of the Immune System
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

40. Activation of Lymphocytes
Figure 12.9

41. Humoral (Antibody-Mediated) Immune Response
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)

42. Humoral (Antibody Mediated) Immune Response
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)

43. Humoral Immune Response

44. Secondary Response Memory cells are long-lived
A second exposure causes a rapid response
The secondary response is stronger and longer lasting

45. Active Immunity Your B cells encounter antigens and produce antibodies
Active immunity can be naturally or artificially acquired

46. Passive Immunity 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”

47. Immunoglobulin Classes
I. IgG
Structure: Monomer
Percentage serum antibodies: 80%
Location: Blood, lymph, intestine
Half-life in serum: 23 days
Complement Fixation: Yes
Placental Transfer: Yes
Known Functions: Enhances phagocytosis, neutralizes toxins and viruses, protects fetus and newborn.

48. Immunoglobulin Classes
II. IgM
Structure: Pentamer
Percentage serum antibodies: 5-10%
Location: Blood, lymph, B cell surface (monomer)
Half-life in serum: 5 days
Complement Fixation: Yes
Placental Transfer: No
Known Functions: First antibodies produced during an infection. Effective against microbes and agglutinating antigens.

49. Immunoglobulin Classes III. IgA
Structure: Dimer
Percentage serum antibodies: %
Location: Secretions (tears, saliva, intestine, milk), blood and lymph.
Half-life in serum: 6 days
Complement Fixation: No
Placental Transfer: No
Known Functions: Localized protection of mucosal surfaces. Provides immunity to infant digestive tract.

50. Immunoglobulin Classes IV. IgD
Structure: Monomer
Percentage serum antibodies: 0.2%
Location: B-cell surface, blood, and lymph
Half-life in serum: 3 days
Complement Fixation: No
Placental Transfer: No
Known Functions: In serum function is unknown. On B cell surface, initiate immune response.

51. Immunoglobulin Classes V. IgE
Structure: Monomer
Percentage serum antibodies: %
Location: Bound to mast cells and basophils throughout body. Blood.
Half-life in serum: 2 days
Complement Fixation: No
Placental Transfer: No
Known Functions: Allergic reactions. Possibly lysis of worms.

52. Warm-up 05/19
What are the three lines of defense against infection that your body has?
What is involved with each line of defense?
What is the major difference between humoral and cell mediated responses

53. Lines of Defense Against Infection

54. Agenda 05/20 Transplants Disorders of Immunity Computer Lab
Operation Antibody

55. Organ Transplants and Rejection
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

56. Organ Transplants and Rejection
Autografts and isografts are ideal donors
Xenografts are never successful
Allografts are more successful with a closer tissue match

57. Disorders of Immunity: Allergies (Hypersensitivity)
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

58. Disorders of Immunity: Allergies (Hypersensitivity)
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

59. Allergy Mechanisms

60. Disorders of Immunity: Immunodeficiencies
Production or function of immune cells or complement is abnormal
May be congenital or acquired
Includes AIDS – Acquired Immune Deficiency Syndrome

61. Disorders of Immunity: Autoimmune Diseases
The immune system does not distinguish between self and nonself
The body produces antibodies and sensitized T lymphocytes that attack its own tissues

62. Disorders of Immunity: Autoimmune Diseases
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

63. Disorders of Immunity: Autoimmune Diseases
Examples of autoimmune diseases (continued)
Systemic lupus erythematosus (SLE) – affects kidney, heart, lung and skin
Glomerulonephritis – impairment of renal function

64. Self Tolerance Breakdown
Inefficient lymphocyte programming
Appearance of self-proteins in the circulation that have not been exposed to the immune system
Eggs
Sperm
Eye lens
Cross-reaction of antibodies produced against foreign antigens with self-antigens
Rheumatic fever

65. Self Tolerance Breakdown
Cross-reaction of antibodies produced against foreign antigens with self-antigens
Rheumatic fever