12
CHAPTER SUMMARY
One of the least recognized of the body systems, the lymphatic system has been gaining ground in
recognition and understanding over the past two decades, largely due to research into AIDS, cancer,
and autoimmune disorders. Its importance in fighting disease and maintaining healthy homeostatic
balance within nearly all body systems cannot be overstated. Although at first unfamiliar to students,
this system quickly piques their interest as a lifesaving system that deserves their attention.
The two semi-independent parts of the lymphatic system are presented first, beginning with
the lymphatic vessels and followed by the lymphoid tissues and organs. Next is a full description of
body defenses, beginning with an explanation of the nonspecific defenses such as fever and the
inflammatory response, which hinder the entry and spread of pathogens. Specific defenses then follow
with special focus on the antigen-antibody response. Under immune system regulation, they destroy
foreign cells. The cells of the immune system are also outlined and explained.
The next section of the chapter discusses the two types of immune response. Humoral
(antibody-mediated) immunity is described first, highlighting the various roles of B cells and
explaining the differences between active and passive types of humoral immunity. Cellular (cellmediated) immunity is presented next, along with a description of the role T cells play in this type of
immune response.
The final section of this chapter discusses homeostatic imbalances of the immune system.
Organ transplantation and its associated risk of rejection are explained, along with allergies, immunodeficiencies, and autoimmune disorders. Finally, in discussing the developmental aspects of the
lymphatic system, there is an explanation that our immune system begins to wane in later life, making
us more susceptible to cancer, as well as autoimmune and immunodeficiency diseases.
SUGGESTED LECTURE OUTLINE
Part 1: The Lymphatic System (pp. 390–395; Figures 12.3–12.5)
I.
II.
III.
LYMPHATIC VESSELS (pp. 390–392)
A.
Lymph
B.
Edema
LYMPH NODES (pp. 392–394)
A.
Macrophages
B.
Lymphocytes
C.
Afferent Lymphatic Vessels
D.
Efferent Lymphatic Vessels
OTHER LYMPHOID ORGANS (pp. 394–395)
A.
Spleen
B.
Thymus gland
C.
Tonsils
D.
Peyer's Patches
E.
Mucosa-Associated Lymphatic Tissue (MALT)
Part 2: Body Defenses (pp. 395–417)
I.
II.
NONSPECIFIC BODY DEFENSES (pp. 396–400; Table 12.1)
A.
Surface Membrane Barriers
B.
Cells and Chemicals
1.
Phagocytes
2.
Natural Killer Cells
3.
Inflammatory Response
a.
Histamine
b.
Chemotaxis
c.
Diapedesis
C.
Antimicrobial Chemicals
1.
Complement
2.
Interferon
D.
Fever
1.
Pyrogens
SPECIFIC BODY DEFENSES: THE IMMUNE SYSTEM (pp. 400–417; Figure 12.19)
A.
Antigens (Ag)
B.
Cells of the Immune System: An Overview
1.
Lymphocytes
2.
Macrophages
C.
Humoral (Antibody-Mediated) Immune Response (Figure 12.13)
1.
Clonal Selection
D.
Active and Passive Humoral Immunity
1.
Naturally Acquired
2.
Artificially Acquired—Vaccines
3.
Monoclonal antibodies
E.
Antibodies (Immunoglobulins, Igs)
1.
Basic Antibody Structure
2.
Antibody Classes
3.
Antibody Function
a.
Neutralization
b.
Agglutination
c.
Precipitation
F.
Cellular (Cell-Mediated) Immune Response
1.
Antigen Presentation
2.
Cytotoxic (Killer) T Cells
3.
Helper T Cells
G.
Organ Transplants and Rejection
1.
Autografts
2.
Isografts
3.
Allografts
4.
Xenografts
H.
Disorders of Immunity
1.
Allergies
2.
Immunodeficiencies
3.
Autoimmune Diseases
Part 3: Developmental Aspects of the Lymphatic System and Body Defenses
I.
DEVELOPMENTAL ASPECTS OF THE LYMPHATIC SYSTEM AND BODY
DEFENSES (pp. 417–421)
A.
Lymph Node Swelling (p. 417)