1. Copyright © 2007 Pearson Education, Inc
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

2. Lymphatic System Organization
Lymphatic System Definitions
Pathogens病原—Organisms that cause disease
Lymphatic System淋巴系統—Cells, tissues, and organs that play a central role in the body’s defenses against pathogens
Lymphatic system consists of vessels淋巴管 (lymphatics) filled with lymph淋巴液 connected to lymphatic organs淋巴器官

3. Lymphatic System Organization
扁桃腺
The Components of the Lymphatic System
右淋巴管 胸腺 胸管 脾臟
Figure 14-1

4. Lymphatic System Organization
Functions of the Lymphatic System
Produce, maintain, distribute lymphocytes淋巴球
Lymphocytes attack invading organisms, abnormal cells, foreign proteins
Maintain blood volume
Help eliminate local variations in interstitial fluid concentration
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

5. Lymphatic System Organization
Lymphatic Vessels
Lymph flows inside
Begin as lymphatic capillaries in the tissues
Lymph empties into venous system
At thoracic duct
At right lymphatic duct
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

6. Lymphatic System Organization
Lymphatic Capillaries
Figure 14-2(a)

7. Lymphatic System Organization
Lymphatic Capillaries
Figure 14-2(b)

8. Lymphatic System Organization
The Lymphatic Ducts and the Venous System
Figure 14-3

9. Lymphatic System Organization
T cells (80%)
Cytotoxic T cells 胞毒性T細胞
Provide cell-mediated immunity細胞性免疫
Attack foreign and virus-infected cells
Regulatory T cells 調節性T細胞
Helper T cells 輔助性T細胞
Suppressor T cells 抑制性T細胞
B cells (10~15 %)
Can become plasma cells 漿細胞
Specific to a particular antigen 抗原
Produce antibodies 抗體 that react with that antigen
Responsible for humoral 體液 or antibody-mediated immunity抗體調節性免疫
NK (natural killer) cells 自然殺手細胞
Provide immunological surveillance監視
Attack cells
Foreign cells
Virally-infected cells
Cancerous cells

10. Lymphatic System Organization
The Origins of Lymphocytes

11. Lymphatic System Organization
Lymphoid Nodules 淋巴結
Consists of loose connective tissue containing densely packed lymphocytes
Tonsils are lymphoid nodules in the pharynx wall
咽扁桃
顎扁桃
舌扁桃

12. Lymphatic System Organization
Lymphoid Organs
Important lymphoid organs include:
Lymph nodes
Thymus
Spleen
Located in areas that are vulnerable to pathogens
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

13. Lymphatic System Organization
Lymph Nodes
Encapsulated masses of lymphoid tissue containing lymphocytes
Monitor and filter lymph
Remove antigens
Initiate immune response

14. Lymphatic System Organization
The Thymus
Lies behind sternum
T cells divide and mature there
Shrinks after puberty
Produces thymosins
Hormones that regulate T cell development
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

15. Lymphatic System Organization
The Thymus 隔膜
Figure 14-7

16. Lymphatic System Organization
The Spleen
White pulp白髓
Resembles lymphoid nodules
Removes antigens
Initiates immune response
Red pulp紅髓
Contains red blood cells
Recycles damaged or out-dated RBCs
Stores iron from recycled RBCs
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

17. Lymphatic System Organization
The Spleen
Figure 14-8

18. Lymphatic System Organization
Overview of Body’s Defenses
Non-specific defenses非特異性防治: Protect against any threat
Physical Barriers
Skin, hair, & skin secretions
Digestive epithelia, & secretions
Phagocytes
Microphages (neutrophils, eosinophils)
Macrophages
Immunological Surveillance
NK cells: Find, kill cancer and virus-infected cells
Interferons 干擾素
Small proteins released by virus-infected cells
Cytokines細胞激素 that trigger release of anti-viral proteins that inhibit virus production
Complement System 補體
Complex system of proteins
Initiate chain reaction (positive feedback)
Destroy target cell membranes
Stimulate inflammation, attract phagocytes
Inflammatory Response: Coordinated non-specific response to tissue injury
Fever
Temperature greater than 99ºF
Inhibits pathogens
Accelerates metabolism
Specific defenses特異性防治
Protect against particular threats
Responds to antigens

19. Nonspecific Defenses
Figure 14-9 (3 of 7)

20. Specific Defenses: Immunity
Types of Immunity
Innate immunity先天性免疫
Genetically determined
Present at birth
Acquired immunity後天性免疫
Active
Follows exposure to antigen
Passive
From transfer of antibodies from outside source
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

21. Specific Defenses: Immunity
Types of Immunity
Figure 14-11

22. Specific Defenses: Immunity
Classes of Antibodies
Immunoglobulin G (IgG)
Resistance to pathogens
Immunoglobulin M (IgM)
First antibody secreted
Immunoglobulin A (IgA)
Found in glandular secretions
Immunoglobulin E (IgE)
Stimulates inflammation
Immunoglobulin D (IgD)
Found on surface of B cells
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

23. Specific Defenses: Immunity
Primary and Secondary Immune Response
Primary response—Antibodies produced by plasma cells after first exposure to antigen
Secondary response—Maximum antibody levels produced by subsequent exposure to the same antibody
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

24. Specific Defenses: Immunity
The Primary and Secondary
Immune Responses
Figure 14-16

25. Specific Defenses: Immunity
Hormones of the Immune System
Interleukins (IL)
Sensitize T cells
Stimulate B cells
Enhance non-specific defenses
Interferons
Slow the spread of viruses locally
Tumor necrosis factors (TNF)
Slows growth, kills tumor cells
Phagocytic regulators
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

26. Patterns of Immune Response
A Summary of the Immune Response and Its Relationship to Nonspecific Defenses
Figure 14-17

27. Patterns of Immune Response
Immune Disorders
Autoimmune disorders
Mistaken attack on body’s own tissues
Immunodeficiency disease
Disease (e.g., AIDS) or a congenital block of immunity
Allergies
Inappropriate or excessive response to allergens
Age-related loss of effectiveness
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

28. Patterns of Immune Response
Types of Allergies
Immediate hypersensitivity (Type I)
Cytotoxic reaction (Type II)
Immune complex disorders (Type III)
Delayed hypersensitivity (Type IV)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings