Understanding the Immune System and its Defenses against Pathogens

1. 31.2 Immune System 2.1 Atoms, Ions, and Molecules Set up Cornell Notes on pg. 61 • Topic: 31.2 Immune System • Essential Question(s): • How does the immune system work with other body systems to prevent and fight diseases? • How do phagocytes help to fight infections? KEY CONCEPTThe immune system consists of organs, cells, and molecules that fight infections.

2. KEY CONCEPTThe immune system consists of organs, cells, and molecules that fight infections.

3. Pg. 61 Write your own definition of the immune system: • The immune system is the body system that fights off infection and pathogens.

4. Pg. 60 • With your table: Make a list of some of the “defenders” of your body • WBCs (Phagocytes/T-cells/B-cells) • Proteins (Interferons/Complement Proteins/ Antibodies) • Hair • Skin • Earwax • Mucous membranes

5. Defending Your Body Against Disease • 10m33s • During the video, add any other body defenses not on your list

6. Think of your body as a heavily guarded castle. When pathogens invade they must break down the outer wall or find a way around it. If the intruders get past the physical barriers, they must face your body’s fighters in hand-to-hand combat. • Invaders are winning= you are sick • Your body is winning= you are healthy

7. SKIN • First line of defense against pathogens!!!! • Protection from infection • Oil glands in skin • Inhibit the growth of bacteria • Cuts and wounds are entry points

8. Besides skin, what are some other entry points? • Eyes • Nose • Ears • Mouth • Excretory Organs (lungs)

9. Mucous membranes in these openings trap pathogens entering the body. • The circulatory system transports immune cells.

10. How Your Body Fights Germs • 2m7s

11. The Bodies’ Defenders 946-947 White Blood Cells Proteins 1.Basophil 2. Mast Cell 3. Neutrophil 4. Macrophage • Phagocyte 5. Lymphocyte • T-cells • B-cells 6. Eosinophil 1. Complement proteins 2. Antibodies 3. Interferons Know the function of each. Include an illustration

12. White Blood Cells White blood cells: Find and kill pathogens that have gotten past the body’s external barriers

13. 6 Main types of WBC • Basophils • Mast cells • These cells cause inflammation in the blood stream and other body tissues

14. 6 Main types of WBC **Mast cells: React by discharging their contents, histamine

15. 3. Macrophage 4. Neutrophil These cells called phagocytes, destroy viruses, bacterium, fungi, and dead or damaged body cells by engulfing them

16. 5. These cells are called lymphocytes: T-Cells: destroy body cells that are infected (direct attack) B-Cells: produce proteins (antibodies) that inactivate pathogens that haven't infected body cells yet (attack foreign molecules outsidethe cells)

17. 6. Eosinophil: inject poisonous packets into parasites, such as protozoa

18. Proteins The immune system uses three types of proteins to fight off invading pathogens:

19. Complement Proteins: made by white blood cells • Can weaken pathogen’s cell membrane allowing water in so it will burst • attract phagocytes to the infected area

20. 2) Antibodies: made by B cells • Attack pathogens by “binding”themselvesto the pathogen to prevent them from attacking healthy cells • Cause pathogen’s to clump, making it easier for phagocytes to engulf and destroy

21. 3) Interferons: produced by body cells infected by a virus • Stimulate uninfected body cells to produce enzymes that will prevent viruses from entering and infecting them • ***If a virus can’t enter it- it can’t reproduce!

22. Members of the Immune System • 2m27s

23. Passive and Active Immunity Passive immunity: occurs WITHOUT the body undergoing an immune response • In DNA • Passed from mother to child Active immunity: is immunity in response to a specific pathogen that has infected OR is infecting your body • Your body actually has to produce the immunity • Keeps you from becoming sick the second time you come in contact with a pathogen

24. Body Story: Body Snatchers P.60 • “Body Snatchers Video Notes” • *Focus on the changes of the body after being infected with influenza virus • At least 10 bullets

25. What does the virus do to her cells? • What causes Holly’s pain symptoms? Why? • Your body has a natural thermostat (98.6). Why does her body react with a fever? • Why was it “good” that Holly couldn’t find pain medicine? • Why does it take the body so long to find the helper T and B cells? • The video said the specific T cell had been “waiting for 25 years” Hypothesize where you think she got it from?

26. 1. What does the virus do to her cells? • “Hijacks her cell”- forces it to produce more of the virus • 2. What causes Holly’s pain symptoms? Why? • Holly’s body is creating the pain symptoms. This lets her know that something is wrong- It is the result of her body fighting the invader. Allows her to “rest” so her body can use her energy to fight the invader. • 3. Your body has a natural thermostat (98.6). Why does her body react with a fever? • 98.6 allows for a perfect “breeding ground” for the virus. By heating up her body the virus cannot produce at such a fast rate. • 4. Why was it “good” that Holly couldn’t find pain medicine? • Pain medicine would reduce her fever, allowing the virus to produce at its full rate. • 5. Why does it take the body so long to find the helper T and B cells? • They are only 2 cells in trillions. Your body needs to locate the proper cells to fight the virus. • 6. The video said the specific T cell had been “waiting for 25 years” Hypothesize where you think she got it from? • She was born with it. Passed on from her mother to her.