31 2 Immune System The Bodies Defenders 946

31. 2 Immune System The Bodies’ Defenders 946 -947 White Blood Cells Phagocyte T-Cells B-Cells • Function • Illustration Proteins Complement Proteins Antibodies • Function • Illustration Interferons

Set Cornell Notesand on pg. 31. 1 up. Pathogens Human Illness 73 2. 1 Atoms, 31. 2 Ions, Immune System and Molecules • Topic: 31. 2 Immune System • Essential Question(s): 1. How does the immune system work with other body systems to prevent and fight diseases? 2. How do phagocytes help to fight infections? KEY CONCEPT The immune system consists of organs, cells, and molecules that fight infections.

31. 2 Immune System KEY CONCEPT The immune system consists of organs, cells, and molecules that fight infections.

31. 2 Immune System • Pg. 72 Write your own definition of the immune system: • The immune system is the body system that fights off infection and pathogens.

31. 2 Immune System Pg. 72 • 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

31. 2 Immune System Defending Your Body Against Disease • 10 m 33 s • During the video, add any other body defenses not on your list

31. 2 Immune System • 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-tohand combat. • Invaders are winning= you are sick • Your body is winning= you are healthy

31. 2 Immune System What is our first line of defense against pathogens? • SKIN!!!!!!

31. 2 Immune System 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

31. 2 Immune System Besides skin, what are some other entry points? • • • Eyes Nose Ears Mouth Excretory Organs (lungs)

31. 2 Immune System – Mucous membranes in these openings trap pathogens entering the body. – The circulatory system transports immune cells.

31. 2 Immune System Pg. 72 How do we heal? *Discuss with your table the order in which a cut heals (6 steps) 1. Cut yourself 2. Bleed 3. Form blood clot 4. Blood clot dries out- Scab is formed 5. Skin cells divide and multiply- (mitosis) 6. Scab falls off *Creates a barrier between bacteria on skin and the tissue below

31. 2 Immune System How Your Body Fights Germs • 2 m 7 s

31. 2 Immune System Meet 6 of the body’s defenders: 1) phagocyte- Destroys viruses, bacterium, and fungi by engulfing them Ex: macrophage

31. 2 Immune System 2) T cells- Destroy body cells that are infected 3) B cells- Produce proteins that inactivate pathogens that haven't infected body cells yet

31. 2 Immune System 4) Complement Proteins: made by white blood cells, and weaken pathogen’s cell membrane allowing water in so it will burst

31. 2 Immune System 5) Antibodies: made by B cells • Attack pathogens by “binding” themselves to the pathogen to prevent them from attacking healthy cells • Cause pathogen’s to clump, making it easier for phagocytes to engulf and destroy

31. 2 Immune System 6) 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!

31. 2 Immune System Members of the Immune System • 2 m 27 s

31. 2 Immune System • Body Story: Body Snatchers • “Body Snatchers Video Notes” • *Focus on the changes of the body after being infected with influenza virus • At least 10 bullets 20

31. 2 Immune System 1. What does the virus do to her cells? 2. What causes Holly’s pain symptoms? Why? 3. Your body has a natural thermostat (98. 6). Why does her body react with a fever? 4. Why was it “good” that Holly couldn’t find pain medicine? 5. Why does it take the body so long to find the helper T and B cells? 6. The video said the specific T cell had been “waiting for 25 years” Hypothesize where you think she got it 21 from?

31. 2 Immune System • 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. 22