Immune System

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Immune System

• Chapter 43

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Introduction to the Immune System

• An animal must defend itself against unwelcome
  intruders.
• It must also deal with abnormal body cells,
  which, in some cases, may develop into cancer.
• Two major kinds of defense have evolved to
  counter such threats.
• Innate Defenses
• Acquired Defenses

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Overview of the Immune System
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External Barriers

• Skin
• Mucous membranes
• Secretions

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Internal Cellular Defenses

• Phagocytic cells
• Neutrophils
• Monocytes
• Eosinophils
• Dendritic cells

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Internal Cellular Defenses
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Phagocytic Responses

• Pseudopodia
• Ingestion
• Vacuole
• Fuse with lysosome
• Digestion
• Exocytosis

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Internal Cellular Defenses

• Natural Killer Cells
• Non-specific
• Perforins
• Apoptosis

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Internal Chemical Defenses

• Interferons
• Complement proteins

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Inflammatory Response
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Inflammatory Response

• Cardinal signs of inflammation
• Local versus systemic inflammation
• Septic shock

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ACQUIRED IMMUNITY

• All cells have cell surface macromolecules
• Adaptive immunity is sensitive to specific
  infections
• Antigens distinguish self versus non-self

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ACQUIRED IMMUNITY
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ACQUIRED IMMUNITY
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Humoral Immunity

• Also known as antibody-mediated immunity
• Utilizes B-lymphocytes
• Recognizes antigen directly
• Made in the bone marrow

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Clonal Selection and Proliferation
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Humoral Immunity
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Antibody Structure
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Antibody Classes
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Antibody Classes
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Antibody Functions
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Cell-Mediated Immunity

• Utilizes T-lymphocytes
• T-cells are made in the bone marrow but mature in
  the thymus gland.
• Cannot recognize antigens directly

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Cell-Mediated Immunity
CLASS I MHC PROTEIN
CLASS II MHC PROTEIN
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Helper T-Lymphocyte Stimulation
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Helper T-cells stimulate B-cells
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Cytotoxic T-Lymphocyte Stimulation
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Overview of Adaptive Immunity
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Adaptive Immunity
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Problems with the Immune System

• Blood Transfusion Reaction
• Tissue Rejection
• Allergies
• Autoimmune disease
• Immunodeficiencies

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Blood Transfusion Reactions
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Blood Transfusion Reactions
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Rhesus Factor
Blood Type Presence of D Antigen? Type of Antibody? Receive?
Rh Positive Yes None and -
Rh Negative No Anti-D - only
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Tissue Transplant and Rejection

• Autograft
• Isograft
• Allograft
• Xenograft

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Allergies or Hypersensitivities

• Type I
• Type II
• Type III
• Type IV

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Autoimmune Diseases

• Multiple sclerosis
• Rheumatoid arthritis
• Systemic lupus
• Grave's disease
• Type I diabetes mellitus

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Immunodeficiency Diseases

• Primary Immunodeficiency
• a.k.a. inborn
• SCID
• Secondary Immunodeficiency
• a.k.a. acquired
• Drugs
• Stress and Hodgkins
• AIDS