Aim: How does our body come under attack?

What is a disease? Disease is any condition that prevents the body from working as it should. As a result the body may fail to maintain homeostasis.

What can cause disease? Genetics Lifestyle choices Pathogens Organ malfunction Toxins

What are pathogens? Foreign Invaders! (not aliens)

Types of Pathogens Bacteria Viruses Fungi Parasites

Bacteria Prokaryotes (no nucleus, missing organelles) Unicellular (one cell)

Examples: Strep throat Salmonella Syphilis (STD)

How can we treat bacterial infections? Antibiotics are drugs used to stop infections by bacteria. Antibiotics will not work against viruses!! SuperBugs!!

Virus A VIRUS IS NOT A CELL (IT IS NOT ALIVE ) Made of: DNA + a Coat around it

They can only reproduce INSIDE a cell. A virus works by injecting its DNA into YOUR cells and hijacking them It turns your cell into a virus producing factory… then causes it to explode when it’s done! They can only reproduce INSIDE a cell. A virus works by injecting its DNA into YOUR cells and hijacking them It turns your cell into a virus producing factory… then causes it to explode when it’s done! Viruses are GRIMEY

Examples HIV Chicken Pox Influenza (the flu)

Fungus Athlete ’ s foot Ring worm What can the doctor Prescribe? Anti-fungal medicine

Parasites Some animals and one-celled organisms survive by living and feeding on other organisms (their host). Example: tapeworms and heartworms

How do pathogens get in your body? Air Contact Water Blood & bodily fluid

Diagnosing – determine the disease you have Diagnosis is made based on symptoms and an examination

Prevention vs. Treatment Prevention – ways to avoid getting the disease. Treatment – ways to help people with a disease to get better.

Aim: How does our body defend us from pathogens? Flu attack!

1 st Line of Defense Skin Mucus Hair Tears in eyes Acid in stomach

2 nd Line of Defense The Immune System Made of proteins, cells, and tissues that identify and defend the body against foreign chemicals and organisms

White Blood cells Warrior Cells! Defenders of the body Eat the bad guys to destroy them

How does our immune system identify pathogens? A ID tag made of proteins identifies the invader as foreign This ID tag is called an antigen. Antigen

What happens after we identify the foreign invader? Our body makes antibodies, which are their weapons against the foreign antigens. Antibodies are Y-shaped weapons

Antibodies Pathogen Antigens Antibodies Antibodies find the Antigens on the pathogen & targets it for destruction !

How do antibodies destroy pathogens? When the antibody attaches to the antigen, it tears open the bad guy’s (pathogen’s) cell membrane– and the bad guy dies!!! It also tells your immune system cells that this guy is ready to be eaten alive!

How are locks & keys similar to antigens and antibodies? Antibodies are made specifically to match the shape of the antigen. Antibodies are made specifically to match the shape of the antigen.

Antibody vs. Antigen Antibody – weapon found in your body Antigen – ID tag found on the pathogen

Our immune system “remembers” bad pathogens it has fought in the past It has weapons built up so the next time the pathogen enters your body, you are ready to defend yourself! Our Immune System has a good memory!

The second response to the same pathogen triggers a quicker and stronger response. ** After the first response, the immune system “remembers” specific pathogens by leaving behind cells that protect the body for years (memory cells).

DO NOW: What is immunity? Immunity: When a person is protected from getting a certain disease. Survivor- Tribal Immunity

Aim: How does your body become immune to disease? Farms & Better Immune systems

Types of Immunity From mother Making your own antibodies to attack pathogens Making your own antibodies to attack pathogens Vaccines

How was the first Vaccine developed? English physician Edward Jenner developed an inoculation against smallpox in Armed with the knowledge that milkmaids who had been exposed to cowpox, a relatively mild affliction, didn't come down with smallpox, Jenner intentionally infected an eight-year-old boy with cowpox. Two months later he infected the boy again, this time with smallpox. As Jenner expected, the child didn't come down with the disease -- he was immune.

What is a vaccine? A vaccine is a dose of a pathogen destroyed so it is no longer harmful, but it still has the antigens present. Weakened Pathogen Antigen Antibody These antigens trigger an immune response.

How do scientists make vaccines? accines.htmlhttp:// accines.html 1)Obtain pathogen 2)Treat pathogen to kill or weaken it. 3)Inject altered pathogen (vaccine) into organism. 4)Body responds to antigens by making antibodies & having cells attack invader. 5) Some white blood cells remain in the body to protect the organism from future attacks.

What happens when you get invaded by the real pathogen? Memory Cells are already present and will multiply quickly and destroy the invader before it has the chance to cause the disease. Memory Cells

Immune response Antibody Concentration Time First exposure Second exposure Interval between exposures Vaccine Real Pathogen

Bioterrorism vaccines Today there is mounting concern about the threat of a bioterrorist attack using smallpox -- so much concern that in October 2001 the American government decided to order enough vaccines to protect every U.S. citizen. Smallpox has a fearsome reputation, having killed more people in history than any other infectious disease.

Aim: How can the immune system malfunction?

How can your immune system malfunction? 1.Allergies 2.Asthma 3.Autoimmune Disease 4.Organ Transplants

What is an allergy? An allergy is a quick immune system reaction to substances that are normally harmless Can you think of materials that can cause allergic reactions?

What are things that cause allergies? HOUSE DUST BEE POLLEN MOLD RAGWEED Allergens

Allergic reactions Histamines are chemicals that cause inflammation Inflammation: blood vessels get larger to send blood to area. You get Itchy, warm, red. Hives, nausea, or shock What can we take for allergies? =10

Asthma is an allergic reaction Allergic reaction that causes your respiratory system to swell up – you cant breathe well

Autoimmune disease The immune System mistakes your own cells for the bad guys, and attacks them! Ex: Diabetes, Multiple Sclerosis

Why are organ transplants difficult? This is a kidney being removed from a donor The donor will have his own ID tags on the cell membrane. What are these ID tags called? Antigens!

How will the recipient react? A transplanted organ is recognized as foreign and is attacked by the immune system (REJECTION). The chance of REJECTION is less when the donor and recipient are closely related or when anti-rejection medication is used.