1. Chapter 12 Immunity and Body Defenses
What is the difference between:
Active and Passive Immunity?
What is Specific/Non-Specific Defenses?
What is the Immune Response?
What is the Inflammatory Response?

2. Immune System A “Functional System” Not a traditional organ system
Fight Pathogens (harmful, disease-causing microorganisms)
Uses molecules and immune cells (lymphocytes and monocytes)
Protects from most bacteria and viruses
Protection for transplant organs/grafts

3. Organs of the Immune System

4. Immunity
Using cell attack, or chemicals and antibody molecules to resist disease
Resistance of an organism to diseases or any particular infection
Involves both specific and non-specific components

5. Specific or Non-Specific Defenses

6. Non-Specific Body Defenses
Responds immediately to protect the body from all foreign substances
Provided by intact skin and mucous membranes, and cellular proteins
Don’t Forget!!!
Surface Membrane Barriers:
first line of defense for skin and body membranes

7. Skin and Mucous Membranes
—Secretions and Sebum are acidic to prevent bacterial growth
—Keartin provides resistance against invaders
—Mucus, Nasal Hairs and Cilia will trap debris
—Gastric juice, Vaginal Acid Mantle, Tears and Saliva Inhibit growth

8. Other Non-Specific Defenses
Cell and Chemical Defenders Provide defense against pathogens
Phagocytesengulf and destroy pathogens
Natural Killer Cellsdirect attack of virus or cancer cells

9. Antimicrobial Chemicals
Interferonsreleased by infected cells to mobilize immune system
Complement(plasma proteins) intensifies the inflammatory response
Urinecleanses the lower urinary tract

10. Fever High body temperatures inhibit bacterial growth
Enahances body repair
Fosters the inflammatory and Immune responses

11. Inflammatory Response
Triggered when body tissues are injured
Signs and Symptoms:
Redness, Heat, Swelling and Pain
Inflammatory Responsea form of non-specific body defense
--Disposes of dead cells and tissues
--Promotes tissue repairs
--Prevents spread of agent to adjacent tissues
--Affected area releases chemicals to attract phagocytes

12. Inflammatory Response

13. Specific Body Defenses
Commonly called the immune system Defends against a particular foreign substance Antigenforeign substance to the body a substance capable of prompting the immune response --Normally not part of our own body --The strongest antigens are in protein form

14. Antigens and Antibodies

15. Immune Response

16. Immune Response
Immune Response is the immune system’s response to a threat:
Increases the Inflammatory response
Protects against a specific invader
Primes the body for future attacks
Antigens are foreign molecules recognized as invaders
Provides Antibodies

17. Immune System

18. Specific Defense Action
Antibodies—unique proteins that protect against future attack
Humoral ImmunityProvided by antibodies present in the body’s fluids
Cellular (Cell-Mediated) ImmunityLymphocytes defend the body acting on targets

19. Cells of the Immune System
Lymphocytes and Macrophages:
B Lymphocytes and T Lymphocytes (Helpers!)
Phagocytic Macrophages fight invaders
B CellsProduce antibodies and oversee humoral immunity
T Cells Non-Antibody producing cells

21. B and T Cells
B and T Cells generate from hemocytoblasts in red marrow
T Cells originate from the Thymus Gland
T Cells continuously circulate through the body
B Cells develop immunocompetence in the bone marrow
Once mature—B and T Cells migrate to the Spleen and Lymph Nodes

22. B Cell Response

23. T Cell Response

24. Macrophages
Distributed throughout lymphoid organs and connective tissues
Arise from monocutes in bone marrow
Engulf foreign particles and present antigens to T cells
Produce Monokines—Proteins important in the immune response
Remain fixed and antigens come to them

25. Active Immunity
Active Immunity—B Cells encounter antigens and produce antibodies against them
Naturally acquired during infections
Artificially acquired (Vaccines)
Vaccines a preparation of killed microorganisms, living attenuated organisms, or living fully virulent organisms that is administered to produce or artificially increase immunity to a particular disease

26. Why Vaccinate? Vaccine Benefits:
not exposed to signs or symptoms of a disease
stimulate antibody production

27. Passive Immunity Antibodies are obtained from serum of a donor
 Cells are not challenged by the antigen
Examples:
Fetus gets immunity from the mother
Gamma Globulin is injected for a snake bit