Download 22-03_pptlect

Anatomy & Physiology
SIXTH EDITION
Chapter 22, part 3
The Lymphatic System
and Immunity
PowerPoint® Lecture Slide Presentation prepared by
Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Frederic H. Martini
Fundamentals of
SECTION 22-4
Specific Defenses
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Forms of immunity
• Innate immunity
• Genetically determined
• Present at birth
• Acquired immunity
• Not present at birth
• Achieved by exposure to antigen
• Active immunity
• Passive immunity
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.14 Types of Immunity
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.14
Properties of immunity
• Specificity – activated by and responds to a
specific antigen
• Versatility – is ready to confront any antigen at
any time
• Memory – “remembers” any antigen it has
encountered
• Tolerance – responds to foreign substances but
ignores normal tissues
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
The immune system response
• Antigen triggers an immune response
• Activates T cells and B cells
• T cells are activated after phagocytes exposed
to antigen
• T cells attack the antigen and stimulate B cells
• Activated B cells mature and produce antibody
• Antibody attacks antigen
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.15 An Overview of the Immune
Response
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.15
SECTION 22-5
T cells and Cell-mediated Immunity
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Major types of T cells
• Cytotoxic T cells (TC) – attack foreign cells
• Helper T cells (TH) – activate other T cells and B
cells
• Suppressor T cells (TS) – inhibit the activation of
T and B cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Antigen presentation
• Antigen-glycoprotein combination appears on a
cell membrane
• Called MHC proteins (Major
Histocompatibility Complex)
• Coded for by genes of the MHC
• T-cells sensitive to the antigen are activated upon
contact
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
MHC classes
• Class I – found on all nucleated cells
• Class II – found on antigen presenting cells and
lymphocytes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Lymphocytes respond to antigens bound to either
class I or class II MHC proteins
• Antigen recognition
• T cell membranes contain CD markers
• CD3 markers present on all T cells
• CD8 markers on cytotoxic and suppressor T
cells
• CD4 markers on helper T cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.16 Antigens and MHC Proteins
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.16
Figure 22.16 Antigens and MHC Proteins
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.16a
Figure 22.16 Antigens and MHC Proteins
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.16b
Activation of CD8 cells
• Responds quickly giving rise to other T cells
• Cytotoxic T cells – seek out and destroy abnormal
cells
• lymphotoxin
• Memory TC cells – function during a second
exposure to antigen
• Suppressor T cells – suppress the immune
response
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.17 Antigen Recognition and the
Activation of Cytotoxic T Cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.17
Figure 22.17 Antigen Recognition and the
Activation of Cytotoxic T Cells
PLAY
Animation: Cytotoxic T Cell Activation
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.17
Activation of CD4 T cells by antigens presented
on class II MHC proteins
• Produces helper T cells and memory T cells
• Activated helper T cells
• Secrete lymphokines that coordinate specific
and nonspecific defenses
• Enhance nonspecific defenses
• Stimulate the activity of NK cells
• Promote activation of B cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.18 Antigen Recognition and Activation
of Helper T cells
PLAY
Animation: Antigen Recognition and Helper T Cell Activation
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.18
Figure 22.19 A Summary of the Pathways of T
Cell Activation
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 22.19