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Published byPaulina Kelley Modified over 7 years ago
TOPIC: Immunity AIM: How does the immune system protect the body against disease?
Topic: Immunity Aim: How does the immune system protect the body against disease? Do Now:
What causes strep throat? Strep throat is a contagious disease caused by infection with group A streptococci bacteria. The symptoms of strep throat include sore throat, fever and stomach pain, along with red and swollen tonsils.
Immune system Protects the body against disease
What is a pathogen? Materials that cause disease (germs) Microorganisms Bacteria, viruses, parasites, fungi…
Immune Response How the body recognizes and defends itself from pathogens
Antigen Any substance that starts an immune response It can be: Pathogens (germs) Other materials (dust, food…)
The Body’s Lines of Defense
Your immune system patrols and protects your body from harmful invaders. If your immune system finds an invader, it takes care of the problem. Immune System Pathogen
1 st line Physical barriers keep pathogens out of the body
skin, mucus, cilia, sweat, tears, saliva, digestive enzymes
2nd line 1. Inflammatory response: WBC’s destroy pathogens
2. Interferons = proteins that help other cells from being attacked by viruses
Antibodies (3 rd line) Proteins that help destroy pathogens Made bc of an immune response
Attach to antigen & slow it down so WBC’s can destroy them
How are antibodies made? 2 types of WBC’s T cells tell B cells to make antibodies
1. Pathogen enters the body
2. Inflammatory response occurs (WBC’s kill germs) OR infection occurs.
3. If infection occurs, the body's immune system produces antibodies and white blood cells to attack the pathogens.
4. Antibodies attach themselves to the pathogens, slowing them down and making it easier for the white blood cells to identify them.
5. White blood cells attack and destroy the pathogens.
2 types of disease 1. Infectious = pathogens spread to another person Ex: cold, flu, AIDS
2. Noninfectious = cannot be spread (not caused by pathogen) Ex: Diabetes, cancer
AIDS Acquired Immune Deficiency Syndrome Infectious disease
Caused by HIV (Human immunodeficiency virus)
Damages immune system by destroying T cells (body can’t fight off pathogens)
How is HIV transmitted? 1. Contact with infected blood 2. Sharing intravenous needles 3. Sexual contact 4. Mother fetus
Allergies An immune response or reaction to substances you are allergic (sensitive) to
Allergen = what you are allergic to (pollen, dust, etc)
Histamines produced (chemicals released by cells that cause symptoms)
Review: 1.What is a pathogen? 2.Explain what makes up your body’s first line of defense. 3.How are antibodies produced? 4.How are infectious diseases different from noninfectious diseases? 5.How does HIV affect the body? 6.What is an allergy?
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