1. OBJ: Given notes, activity sheet SWBAT explain what is meant by pathogens, infectious disease and how our Immune System fights disease with 70% accuracy BRING IN TEXTBOOK DN: Distribute INERH Review Sheets w/ Answer Keys ACT: Introduction to Pathogens, Infectious Disease and Lines of Defense (Notes) Video: Immune System & Human Immune Response Text, read p HW: Complete Infectious Disease and Body’s Defenses Activity Sheets (p. 300, 308), INERH EXAM, Monday, March 23.

2. IMMUNE SYSTEM Pathogens: organisms that cause disease
Infectious disease: a disease caused by a foreign microorganism within the body.
There are four types of pathogens: bacteria, virus, fungi, protists. Pathogens spread by:
1] an infected person
2] soil, food, water
3] a contaminated object
4] an infected animal

3. Three (3) Lines of Defense Against Pathogens
First Line Of Defense: Barriers That Trap & Kill
Skin: dead skin cells flake off removing pathogens from body; outer epidermis acts as a barrier too; rapid scabbing prevents pathogen entry into body.
Breathing Passages: Nose, mouth, throat contains mucus and cilia trapping and removing pathogens. Coughing/sneezing also removes pathogens.
Mouth & Stomach: saliva and stomach acid can kill pathogens.

5. Three (3) Lines of Defense Against Pathogens
Second Line Of Defense: Inflammatory (General) Response
White Blood Cells (WBC): are disease fighting cells. There are many different types of WBC’s, each having its own particular function. Phagocyte (WBC) eat pathogens destroying them.
Inflammation: increased blood flow (enlarges blood vessels) bringing more WBC’s to affected area (red, swollen, warmer).
Fever: increasing body temperature fights infection; pathogens do not grow/reproduce well at higher temperatures.

7. Three (3) Lines of Defense Against Pathogens
Third Line Of Defense: Immune System’s (Targeted) Response
Antigens: unique marker molecules on pathogen.
Antibody: molecular tag that attaches to antigen to recognize as foreign.
Lymphocytes: WBC’s that can distinguish between different kinds of pathogens. Two types:
T-cells (Alarm, Attack): specialized cell that recognizes each kind of pathogen.T-cells multiply, then some attack pathogen (“killer T-cells”) while others activate B – cells.
B-cells (Antibody “Tag” Factory): specialized cells that produce specialized antibodies (proteins) that tag the pathogen for destruction. The antibody binds to the antigen on the pathogen, marking it for destruction by the phagocytes.

8. TAGGED FOR DESTRUCTION
PRODUCED BY B-CELL
ANTIBODY
“TAG”
PHAGOCYTE: eat pathogens
ANTIGEN
Surface molecules
BACTERIA “PATHOGEN”
TAGGED FOR DESTRUCTION