1. Inquiry into Life Twelfth Edition
Lecture PowerPoint to accompany
Inquiry into Life Twelfth Edition
Sylvia S. Mader
Chapter 13
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. 13.1 The Lymphatic System The Lymphatic System
Lymphatic Vessels
Lymphatic Organs
The Lymphatic System Contributes to Homeostasis
Returning excess tissue fluid to the bloodstream
Absorbing fat from the digestive tract and transports them to the bloodstream
Helps defend the body against disease

3. Lymphatic System

4. 13.1 Lymphatic System Lymphatic Vessels A one-way system
Fluid inside is called lymph
Consists of water and solutes
Lymphatic capillaries
Found in most areas of the body
Small, closed-ended vessels
Capillaries merge into larger vessels
These larger vessels carry the lymph into the thoracic and lymphatic ducts
Lymph is returned to the bloodstream

5. 13.1 Lymphatic System Lymphatic Vessels Continued
Larger Lymphatic Vessels
Valves prevent backflow
Movement of lymph is dependent on skeletal muscle contractions
Edema
Localized swelling caused by accumulation of fluids in the tissues (not drained by the lymphatic system)

6. 13.1 Lymphatic System Lymphatic Organs
Contain a large number of lymphocytes, a type of white blood cells
B lymphocytes (B cells)
T lymphocytes (T cells)

7. The Lymphatic Organs

8. 13.1 Lymphatic System Primary Lymphatic Organs Red Bone Marrow
Site of blood cell production
B-cells mature in the bone marrow
Thymus Gland
Site of T-cell maturation

9. 13.1 Lymphatic System Secondary Lymphatic Organs Spleen Lymph nodes
Cleanses the blood
Lymph nodes
Cleanses lymph

10. 13.2 Innate and Acquired Immunity
Innate immunity mechanisms are fully functional without previous exposure to a unwanted substance.
Acquired immunity is dependent upon exposure to specific antigens.
Antigen: Any molecule that stimulates an immune response.

11. 13.2 Innate and Acquired Immunity
Innate Immunity
Physical and Chemical Barriers
Inflammation
Phagocytes and Natural Killer Cells
Protective Proteins

12. 13.2 Innate and Acquired Immunity
Innate Immunity
Physical and Chemical Barriers
Skin and mucous membranes serve as protective barriers
Upper respiratory tract has cilia to remove trapped particles
Oil glands (skin) secretes chemicals harmful to some bacteria
Stomach is acidic
Bacteria (normal flora) in the intestines and other areas out-compete potential pathogens

13. 13.2 Innate and Acquired Immunity
Innate Immunity
Inflammation

14. 13.2 Innate and Acquired Immunity
Innate Immunity
Phagocytes
Phagocytes engulf pathogens via endocytosis
Neutrophils
Monocytes / Macrophages
Natural Killer Cells
Destroy some virus-infected cells and cancer cells by cell-to-cell contact

15. 13.2 Innate and Acquired Immunity
Complement System
Cause holes to form in the outer surface of some bacteria and viruses
Interferons
Proteins produced by cells infected with a virus that protects non-infected cells

16. 13.2 Innate and Acquired Immunity
These defenses are specific against an antigen, they may take 5 to 7 days to become fully activated
Depends upon lymphocytes
B-cells
T-cells

17. 13.2 Innate and Acquired Immunity
B cells and Antibody-Mediated Immunity
Characteristics of B Cells
Antibody-mediated immunity against pathogens
Produced and mature in bone marrow
Reside in lymph nodes and spleen, circulate in blood and lymph
Directly recognize antigen and then undergo clonal selection
Clonal expansion produces antibody-secreting plasma cells as well as memory B-cells

18. Clonal Selection Theory as it Applies to B-Cells

19. 13.2 Innate and Acquired Immunity
Structure of an Antibody
Antibodies are also called immunoglobulins (Ig’s).
Y-shaped
Constant regions
Variable regions

20. Classes of Antibodies

21. 13.2 Innate and Acquired Immunity
T cells and Cell-Mediated Immunity
A macrophage presents a portion of an antigen to T cells
Types of T-cells
Helper T-cells
Cytotoxic T-cells

22. Clonal Selection Model as it Applies to T cells

23. 13.2 Innate and Acquired Immunity
Characteristics of T-Cells
Cell-mediated immunity against virus infected cells and cancer cells
Produced in bone marrow, mature in thymus
Antigen must be presented in groove of an MHC molecule
Cytotoxic T cells destroy nonself protein-bearing cells
Helper T cells secrete cytokines that control the immune response

24. Cell-Mediated Immunity

25. 13.3 Induced Immunity Active Immunity
Develops naturally after a person is infected with an antigen
A person produces an immune response against an antigen
Can be induced by use of vaccines
Is dependent upon the presence of Memory B Cells and Memory T Cells in the body

26. 13.3 Induced Immunity
Vaccines are pathogens or their products that have been treated so they are no longer able to cause disease.

27. 13.3 Induced Immunity

28. 13.3 Induced Immunity Passive Immunity
An individual is given prepared antibodies to combat disease
Is temporary because there are no memory cells

29. 13.3 Induced Immunity Immune Therapies Cytokines and Immunity
Signaling molecules produced by T lymphocytes and macrophages
Interleukins
Cytokines that enhance ability of T cells to fight cancer
Have many potential uses in medicine

30. 13.3 Induced Immunity Monoclonal Antibodies
Group of plasma cells from the same B cell all produce same antibody
Use of monoclonal antibodies
Diagnostic tests
Ex: pregnancy tests
Vehicles for drug delivery
Identification of infections

31. 13.4 Adverse Effects of Immune Responses
Allergies
Hypersensitivities to Substances
Immediate Allergic Response
Can occur within seconds of exposure to an antigen
IgE antibodies attach to mast cells
Allergen attaches to IgE , causing mast cells to release histamine
Histamine is responsible for allergy symptoms
Anaphylactic Shock
Immediate allergic response where allergen enters the blood stream
Histamine causes a sudden, life-threatening drop in blood pressure
Epinephrine can counteract this reaction

32. 13.4 Adverse Effects of Immune Responses
Blood-Type Reactions
In the ABO system, the presence or absence of type A and type B antigens on red blood cells determines a persons blood type.
If antibodies are present against a type of blood, agglutination occurs
Transfusions
Must consider recipient’s antibodies and donor’s antigens to prevent agglutination and transfusion reaction
Type O is universal donor
Neither anti-A nor anti-B antibodies
Type AB is universal recipient
Neither A nor B antigens

33. 13.4 Adverse Effects of Immune Responses

34. Blood Transfusions

35. 13.4 Adverse Effects of Immune Responses
Rh System
Rh+ Rh antigen is present on red blood cells
Rh- Rh antigen is absent on red blood cells
Significant in Pregnancy
If a Rh- mother is pregnant with Rh+ baby
If baby’s cells leak into mother’s bloodstream, she forms anti-Rh antibodies
Attack baby’s RBC’s- hemolytic disease of newborn (HDN)
This can be prevented by giving the Rh- mother anti-Rh immunoglobulins in an injection
The injection must be given before the mother becomes sensitized to produce her own antibodies

36. Hemolytic Disease of the Newborn

37. 13.5 Disorders of the Immune System
Autoimmune Disease
Cytotoxic T-cells or antibodies attack a person’s own cells
Myasthenia gravis - muscle weakness
Multiple sclerosis - neuromuscular disorder
Immune Deficiencies
Immune system is unable to protect the body from disease
Acquired immune deficiency syndrome
Severe combined immunodeficiency syndrome (inherited)