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Immune System - Coggle Diagram
Immune System
Innate (Nonspecific) Immune System
Characteristics
First line of defense
Immediate, rapid response
No memory
Not pathogen-specific
Includes physical, chemical, and cellular defenses
Chemical Defenses
Nonspecific mediators with broad antimicrobial activity
Some always present; some induced during infection
Plasma Protein Mediators
Electrolytes, sugars, lipids
Clotting proteins
Acute-phase proteins
Complement proteins
Cytokines
Complement System
Outcomes:
Opsonization
Inflammation
Chemotaxis
Cytolysis
Cytokines
Soluble signaling molecules
Coordinate immune response
Cellular Defenses
Formed elements of blood:
White blood cells (WBCs)
Differential WBC count (neutrophils, lymphocytes, monocytes, eosinophils, basophils)
Cells of the Adaptive Immune System
B Cells
Mature in bone marrow
Produce antibodies
Responsible for humoral immunity
Activated by antigen binding & T-cell help
T Cells
Develop in thymus
Recognize antigen presented by APCs
Have T-cell receptors (TCRs)
Combat intracellular pathogens & cancer
Antigen-Presenting Cells (APCs)
Macrophages
Dendritic cells
B cells
Types of T Cells
Helper T cells (CD4+)
Activate B cells, macrophages, cytotoxic T cells
Cytotoxic T cells (CD8+)
Kill infected or abnormal host cells
Antigens and Antibodies
Antigens
Molecules recognized by immune system
Trigger adaptive response
Antibodies
Produced by B cells
Specific to antigen
Neutralize pathogens
Mark pathogens for destruction
Results of Antigen–Antibody Binding
Agglutination
Opsonization
Neutralization
Complement activation
Immobilization
ADCC (antibody-dependent cellular cytotoxicity)
Antibody Titer
Measurement of antibody concentration in serum
Indicates strength of immune response
Immunity (Concepts)
Susceptibility → lack of resistance to disease
Immunity → ability to ward off disease
Two major branches:
Innate Immunity (nonspecific)
Adaptive Immunity (specific)
Adaptive Immune System
Key Features
Specific response to particular pathogens
Has memory
Stronger response on second exposure
Slower to activate initially
Historical Basis
Emil von Behring (1901 Nobel Prize)
Work on diphtheria & tetanus toxins
Showed serum-based protection → basis for antitoxins