Download presentation
Presentation is loading. Please wait.
Published byEdward Powell Modified over 9 years ago
1
Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Chapter 67 Review of the Immune System
2
2Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Review of the Immune System Two types of immune responses Natural immunity (innate) Specific acquired immunity Cell-mediated Cell-mediated Antibody-mediated: humoral Antibody-mediated: humoral
3
3Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Immune System: Cells B lymphocytes (B cells) Make antibodies Cytolytic T lymphocytes Cytolytic T cells, CD8 cells Do not produce antibodies Attack and kill target cells directly Helper T lymphocytes Helper T cells, CD4 cells Antibody production by B cells Antibody production by B cells Promote delayed-type hypersensitivity (DTH) Promote delayed-type hypersensitivity (DTH) Activation of cytolytic T cells Activation of cytolytic T cells
4
4Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Immune System: Cells Helper T lymphocytes Helper T cells, CD4 cells Required for an effective immune response Required for an effective immune response Antibody production by B cells Antibody production by B cells Promote DTH Promote DTH Activation of cytolytic T cells Activation of cytolytic T cells
5
5Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Immune System: Cells Macrophages Begin in bone marrow, enter blood as monocytes, and infiltrate tissues, where they evolve into macrophages Principal scavengers of the body Specific acquired immunity Activation of T cells Activation of T cells Final mediators of DTH Final mediators of DTH Phagocytize cells tagged with antibodies Phagocytize cells tagged with antibodies Also play key roles in natural immunity and inflammation
6
6Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Fig. 67–1. Maturation of blood cells.
7
7Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Immune System: Cells Dendritic cells Mast cells and basophils Mediate immediate hypersensitivity reactions Neutrophils (polymorphonuclear leukocytes) Phagocytize bacteria and other foreign particles Eosinophils Attack and destroy foreign particles that have been coated with antibodies of the immunoglobulin (Ig)E class
8
8Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Antibodies Alternative names Immunoglobulins Gamma globulins Family of structurally related glycoproteins Mediate humoral immunity Recognize and bind with specific antigens Produced by B lymphocytes Five classes of antibodies IgA, IgD, IgE, IgG, and IgM
9
9Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Fig. 67–2. Antibody structure.
10
10Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Antigens Molecules that induce specific immune responses May trigger production of antibodies or cytotoxic T cells, or both Antibodies recognize and bind selected small portions of the antigen More than one antibody can bind to the antigen
11
11Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Fig. 67–3. Memory and time limitation of immune responses.
12
12Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Characteristic Features of the Immune Response Specificity Immune responses are triggered by specific antigens Diversity Millions of different antigenic determinants Memory Exposure to an antigen affects the immune system such that re-exposure produces a faster, larger, and more prolonged response Time limitation Selectivity for antigens of nonself origin Targets only foreign antigens (normal conditions)
13
13Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Phases of the Immune Response Recognition phase Antigen recognition by B cells and T cells Activation phase Proliferation Differentiation of activated lymphocytes Effector phase Elimination of antigen
14
14Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Antibody-Mediated (Humoral) Immunity Production of antibodies Interaction of three types of cells B cells B cells Make antibodies Helper T cells (CD4 cells) Helper T cells (CD4 cells) Stimulate B cells Antigen-presenting cells (macrophage or dendritic) Antigen-presenting cells (macrophage or dendritic) Activate CD4 cells
15
15Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Antibody-Mediated (Humoral) Immunity Antibody effector mechanisms Opsonization of bacteria Activation of the complement system Neutralization of viruses and bacterial toxins
16
16Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Fig. 67–4. Major events in antibody-mediated (humoral) immunity.
17
17Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Cell-Mediated Immunity Two branches Delayed-type hypersensitivity (DTH) Activation of helper T cells Activation of helper T cells Activation of macrophages Activation of macrophages Cytolytic T lymphocytes (CTLs, CD8 cells) Activation of cytolytic T cells Activation of cytolytic T cells Recognition of virally infected target cells Recognition of virally infected target cells Mechanism of cell kill Mechanism of cell kill Binding of a CTL to its target cell Release of mediators that kill the target Cause target cell lysis Cause target cell lysis
18
18Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Fig. 67–5. Cell-mediated immunity: delayed-type hypersensitivity.
19
19Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. Fig. 67–6. Cell-mediated immunity: cytolytic T cells.
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.