Chapter 21 THE LYMPHATIC ANDIMMUNE SYSTEMS

21.1 The Lymphatic System

Objectives

When you have completed this section, you should be able to

• list the functions of the lymphatic system;

• explain how lymph is formed and returned to the bloodstream;

• name the major types of cells in the lymphatic system and state their functions;

• name and describe the types of lymphatic tissue; and

• describe the form and function of red bone marrow, thymus, lymph nodes, tonsils, and spleen.

21.2 Nonspecific Resistance

Objectives

When you have completed this section, you should be able to

• identify the body’s three lines of defense against pathogens;

• contrast nonspecific resistance with immunity;

• describe the defensive functions of each kind of leukocyte;

• describe the role of the complement system in resistance and immunity;

• describe the process of inflammation and explain what accounts for its cardinal signs; and

• describe the body’s other nonspecific defenses.

21.3 General Aspects of Specific Immunity

Objectives

When you have completed this section, you should be able to

• define specific immunity;

• contrast cellular and humoral immunity, active and passive immunity, and natural and artificial immunity;

• describe the chemical properties of antigens;

• describe and contrast the development of T and B lymphocytes; and

• describe the general roles played by lymphocytes, antigen-presenting cells, and interleukins in the immune response.

21.4 Cellular Immunity

Objectives

When you have completed this section, you should be able to

• list the types of lymphocytes involved in cellular immunity and describe the roles they play;

• describe the process of antigen presentation and T cell activation;

• describe how T cells destroy enemy cells; and

• explain the role of memory cells in cellular immunity.

21.5 Humoral Immunity

Objectives

When you have completed this section, you should be able to

• explain how B cells recognize and respond to an antigen;

• describe the structure, types, and actions of antibodies;

• explain the mechanism of memory in humoral immunity; and

• compare and contrast cellular and humoral immunity.

21.6 Immune System Disorders

Objectives

When you have completed this section, you should be able to

• distinguish between the four classes of immune hypersensitivity and give an example of each;

• explain the cause of anaphylaxis and distinguish local anaphylaxis from anaphylactic shock;

• state some reasons immune self-tolerance may fail, and give examples of the resulting diseases; and

• describe the pathology of immunodeficiency diseases, especially AIDS.