Activity…  Design an emergency plan to protect people (ex. LRHS students or people attending a concert) from an attack.  If an attack were to occur, what steps would you take to minimize damage? You might want to consider the recent events in Europe to help with this.

INTRODUCTION TO THE IMMUNE SYSTEM

Immune System  Protects the body from  Pathogens  Certain toxins  Immune response recognizes foreign or dangerous molecules and works to eliminate them  Nonspecific (innate)  Specific (acquired)  Communication & Coordination KEY!!

The Invaders...  Bacteria  Viruses  Parasites such as fungi, protista, & worms

NON-SPECIFIC IMMUNITY IN VERTEBRATES

Barriers: 1 st Line of Defense  Physical and Chemical  Prevent pathogen from entering

What keeps invaders from entering?  The Integumentary System…  Skin  Mucous membranes  Mucous  Resident microfauna  How can they help?

Other Barrier Defenses:  Physiological variables  pH of our environment  temperature of our environment  Chemical defenses:  Defensins – saliva & epithelium  Mucin – mucus  Lysozome – many tissues & tears

IF A BARRIER IS BREACHED… Immune system kicks into action

Immune System : 2 branches

What happens when there’s a breach?  How would your cells recognize an invader?  PAMPs on many invaders  Receptors activate phagocytes

LET’S MEET THE PLAYERS…

Phagocytes  Cells that engulf invaders  Common/phago053.html Common/phago053.html  Include:  Neutrophils  Macrophages  Release cytokines that enhance the immune response

Phagocytosis

Natural Killer Cells  Destroy tumor cells & cells infected with some viruses  Destroy cells by both nonspecific &specific processes  Release  Perforins  Granzymes  Causes apoptosis

Cytokines  Peptides/Proteins  Regulate intensity/duration of immune response  Also regulate cell growth, repair, & activation

Types of Cytokines:  Interferons  Tumor Necrosis Factor  Interleukins  Chemokines

Complement System  20+ proteins in plasma & body fluid  Inactive until exposed to antigen  Once activated  cascade reaction

INFLAMMATORY RESPONSE Begins immediately after invasion or injury

Inflammation  Cells release chemical signals  Inflammation activates the complement system  Cytokines signal WBC - chemotaxis Cytokines signal WBC  Macrophages/mast cells stationed in tissues respond  Mast cells release histamine  increased permeability of capillaries

3 Main processes of Inflammatory Response:  Vasodilation  Signals from mast cells  Increased capillary permeability  Volume of interstitial fluid increases  Edema  Increase in phagocytosis

Fever  Symptom of widespread inflammation  Increases phagocytosis  Interferes with microbial replication  Break down lysosomes – destroy cells infected with viruses  Increases action of certain lymphocytes