Thursday, April 17 “A” Day

1. Thursday, April 17 “A” Day • Go over CPR/First Aid Review Assignment • CPR/First Aid Written Exam • “Understanding Infectious Diseases” reading & questions. Mindtrap Question If it takes six men six days to dig six holes, how long will it take one man to dig half a hole? Answer: There is no such thing as Half a hole. A hole is a hole.

2. Time for Exercises

3. Medic First Aid Basic Plus Adult Cpr/First Aid Test • DO NOT write on the test. • Using a #2 pencil, put your answers on the Scantron answer sheet. • When you are finished with the test, turn in your test questions and answer sheet to Mr. Nolan • Grab a Health textbook. Read pages 548-551. Take notes on the reading. • Answer the section review questions on the half sheet of paper.

4. Section 21.1 Understanding Infectious Diseases Objectives Identify the causes of infectious diseases. Describe four ways in which infectious diseases are spread.

5. Fact About 80% of infectious diseases are spread by hand contact. Washing your hands with soap and water is a simple and effective way to prevent the spread of colds and the flu. Do you think most teens wash their hands as much as they should? What do you think are some ways to encourage more frequent hand washing? Myth There isn’t much a person can do to avoid spreading or catching a cold or the flu.

6. Causes of Infectious Diseases • Also known as communicable diseases, infectious diseases (in FEK shus) are caused by organisms or viruses that enter and multiply within the human body. • Microorganisms (my kroh AWR guh niz ums)are organisms that can be seen only through a microscope. • Microorganisms and viruses that cause disease are called pathogens (PATH uh junz). • Pathogens can cause an infectious disease when they enter your body and multiply.

7. Time for Exercises

8. Bacteria • Bacteria (bak TEER ee uh) are simple, single-celled microorganisms. Bacteria live in air, soil, food, and in and on the bodies of plants and animals, including you. • Some bacteria injure cells by giving off poisons called toxins (TAHK sinz). Cell Phone Bacteria Jake Finkbonner

9. Viruses • The smallest pathogens are viruses. • A virus can multiply only after entering a living cell. • The virus then takes over the cell’s reproductive mechanisms, resulting in cell damage or death. How a virus invades your body VIDEO

10. Fungi • Organisms such as yeasts, molds, and mushrooms are known as fungi (FUN jy). • Fungi grow best in warm, dark, moist areas.

11. Protozoans • Single-celled organisms that are much larger and more complex than bacteria are known as protozoans(proh tuh ZOH unz). • Protozoans have the ability to move through fluids in search of food. Malaria Video

12. Other Pathogens Some infectious diseases are caused by animals such as mites, lice, and certain worms.

13. How Pathogens Are Spread • Pathogens can spread through contact with • an infected person • an infected animal • contaminated objects • contaminated food • contaminated soil • contaminated water • The pathogens can then enter the body through breaks in the skin or through the moist linings of the eyes, ears, nose, mouth, or other openings.

14. Infected People • Many infectious diseases are spread through some form of contact with a person who has the disease. • The contact may be direct physical contact. • Infectious diseases can also spread through indirect contact.

15. Infected Animals Some infectious diseases are transmitted to humans through the bites of animals.

16. Contaminated Objects • Some pathogens can survive for a period of time outside a person’s body. • These pathogens can be spread from person to person on objects such as • doorknobs • eating utensils • towels • needles used for body piercings and tattoos

17. Contaminated Food, Soil, or Water • Some pathogens are naturally present in food and soil. • Sometimes water and food become contaminated with pathogens from infected people.

18. Vocabulary infectious disease A disease caused by an organism or virus that enters and multiplies within the human body. microorganism An organism that is so small it can only be seen through a microscope. pathogen A microorganism or virus that causes disease. bacteria Simple, single-celled microorganisms. toxin A poison given off by some bacteria that can injure cells. virus The smallest type of pathogen.

19. Vocabulary fungi Organisms such as yeasts, molds, and mushrooms that grow best in warm, dark, moist areas. protozoan A large and complex single-celled organism.

20. Section 1 Review Questions Key Ideas and Vocabulary • What is a pathogen? Name four types of pathogens. A pathogen is a microorganism or virus that causes disease. Four types are bacteria, viruses, fungi, and protozoans. • 2. How do pathogens cause infectious diseases? Pathogens can cause an infectious disease when they enter the body and multiply. • 3. What is a virus? How are viruses different from • bacteria? A virus is the smallest kind of pathogen. Unlike most bacteria, a virus can multiply only after entering a living cell.

21. Section 1 Review Questions 4. What are four ways that infectious diseases can spread? Infectious diseases can spread through contact with an infected person, an infected animal, contaminated objects, and contaminated food, soil, or water. 5. Applying Concepts If you were traveling to a country where mosquito-borne diseases were common, how would you protect yourself from getting infected? Sample answer: by applying mosquito repellent, by wearing long sleeves and long pants, and by staying indoors during times when mosquitoes are most active 6. Relating Cause and Effect Why do you think that communities boil their drinking water after a water line break? Sample answer: A water line break can allow harmful bacteria to enter the water supply. Boiling contaminated water kills most or all of the harmful bacteria.

22. Understanding Infectious Diseases QUIZ Write the letter of the correct answer using the list on the right. Organisms such as yeasts, molds, and mushrooms.__________ Single-celled organisms that are much larger and more complex than bacteria. __________ Simple, single-celled microorganisms. ________ Microorganisms and viruses that cause disease. _______ The smallest pathogens._______ Pathogens Bacteria Toxins Fungi Protozoan Viruses D E B A F

23. Understanding Infectious Diseases QUIZ Decide whether each statement is true or false. Some infectious diseases are transmitted to humans through the bites of animals. _________ An infected person cannot spread a disease to another person. _______ Pathogens can cause an infectious disease when they enter your body and multiply. ________ It is important to refrigerate food promptly to prevent the growth of harmful bacteria. ________ All pathogens die immediately when they leave a person’s body.________ True False True True False

24. Section 21.2 Defenses Against Disease Objectives Identify the body’s physical and chemical defenses against infectious disease. Describe the inflammatory response. Summarize how the immune system works. Compare passive and active immunity.

25. VIDEO • Protection from Infection

26. Quick Quiz Complete each of these statements with always, sometimes, or never. I ____ wash my hands before meals. When preparing fruits and vegetables, I ____ wash them thoroughly. I am ____ careful to use only my own eating utensils, drinking cups, towels and grooming items. I ____ cover my mouth when I cough or sneeze. If I spend time in wooded areas, I ____ wear insect repellent. For each of your responses, explain how your behavior could affect your chances of getting or spreading an infectious disease.

27. Physical and Chemical Defenses Your body’s first line of defense against infectious disease includes both physical and chemical defenses that prevent pathogens from entering your body.

28. Skin • Your skin serves as both a physical and a chemical barrier against pathogens. • Sweat acts as a chemical barrier. • Old skin cells are shed constantly, and the pathogens on these cells are shed, too.

29. Mucous Membranes • The openings into your body, such as your mouth, eyes, and nose, are covered by protective linings called mucous membranes (MYOO kus). • Mucus traps many pathogens and washes them away. • Mucus contains chemicals and specialized cells that attack pathogens.

30. Cilia • Some of your body’s mucous membranes are lined with tiny hairlike structures called cilia (SIL ee uh). • Together, cilia and mucus help trap and remove pathogens.

31. Saliva and Tears • Your saliva and tears can trap pathogens and wash them away. • Saliva and tears also contain chemicals that attack pathogens.

32. Digestive System • Chemicals in your digestive system kill many pathogens. • The normal motions of the digestive system move pathogens out. • Bacteria that normally live in your digestive system produce substances that can harm or kill invading bacteria.

33. Stomach acidWhen you swallow certain pathogens with food, water, or mucus, acids in your stomach can kill those pathogens. Your Body’s Physical and Chemical Defenses Saliva and tearsSaliva and tears can wash away some pathogens. 1 Mucous membranesMucus traps some pathogens, preventing them from entering your body. 2 3 CiliaCilia help move mucus and pathogens out of your body when you cough or sneeze. 4 SkinYour skin is an effective barrier against many pathogens. 5

34. Inflammation • Inflammation (in fluh MAY shun) is your body’s general response to all kinds of injury, from cuts and scrapes to internal damage. • Inflammation fights infection and promotes the healing process.

35. Phagocytes • Within seconds after your body is injured, the damaged cells release chemicals that cause blood vessels in the injured area to enlarge. • Blood, other fluids, and white blood cells called phagocytes (FAG uh syts) leak out of the enlarged vessels. • Phagocytes engulf and destroy pathogens.

36. Phagocytes This micrograph shows a phagocyte (blue) attacking bacteria (pink). Phagocytes kill pathogens by engulfing and then digesting them.

37. Healing • Phagocytes also give off substances that cause healing to begin. • The inflammation process heals the damage, and the inflammation subsides.

38. The Immune System The immune system (ih MYOON) fights disease by producing a separate set of weapons for each kind of pathogen it encounters.

39. The Immune Response • When a pathogen enters your body for the first time, it often causes disease. • White blood cells called lymphocytes (LIM fuh syts) carry out most of the immune system’s functions. • If a pathogen that has previously attacked your body enters your body again your immune system will quickly recognize the pathogen and launch an immediate attack. • Immunity (ih MYOON ih tee) is your body’s ability to destroy pathogens that it has previously encountered before the pathogens are able to cause disease.

40. T Cells T cells perform several functions. • Killer Tcells destroy any body cell that has been infected by a pathogen. • Helper Tcells produce chemicals that stimulate other T cells and B cells to fight off infection. • Suppressor Tcells produce chemicals that “turn off” other immune system cells when an infection has been brought under control.

41. B Cells • The B lymphocytes, or B cells, produce antibodies. • Antibodies (AN tih bahd eez) are proteins that attach to the surface of pathogens or to the toxins produced by pathogens. • This binding action keeps the pathogen or toxin from harming the body. • The memory capacity of B cells explains why you develop immunity to some diseases you’ve already had.

42. The Immune Response

43. The Lymphatic System • The lymphatic system (lim FAT ik) is a network of vessels that collects fluid from your tissues and returns it to the bloodstream. • The fluid flowing through the lymphatic system is called lymph (limf). • The lymphatic vessels have hundreds of small stations, called lymph nodes.

44. Lymph nodes Lymph vessel The Lymphatic System Your lymphatic system is a complex network of vessels and nodes.

45. Passive and Active Immunity Passive Immunity • Immunity acquired by receiving antibodies from a source other than one’s own immune system is called passive immunity. • This type of immunity is temporary, not lifelong. • It occurs naturally in babies, who receive antibodies from their mothers before birth. • Passive immunity can be artificially acquired.

46. Passive and Active Immunity Active Immunity • Active immunity results from either having a disease or from receiving a vaccine. • Injections, which cause you to become immune to a disease, are called immunizations(im yuh nih ZAY shunz), or vaccinations. • The substance that is injected is called a vaccine (vak SEEN). • Vaccines contain small amounts of dead or modified pathogens or their toxins.

47. Your Immune System: Natural Born Killer • http://www.youtube.com/watch?v=CeVtPDjJBPU&feature=plcp

48. Vocabulary mucous membrane The protective lining that covers any opening into the body. inflammation The body’s general response to all kinds of injury. phagocyte A type of white blood cell that engulfs and destroys pathogens. immune system The body’s most sophisticated defense against pathogens. lymphocyte A type of white blood cell that carries out functions of the immune system.

49. Vocabulary immunity The body’s ability to destroy a pathogen that it has previously encountered before the pathogen is able to cause disease. T cell A type of lymphocyte that helps the immune system destroy pathogens. B cell A lymphocyte that produces antibodies. antibody A protein that attaches to the surface of pathogens or to the toxins produced by pathogens, keeping the pathogen or toxin from harming the body.

50. Vocabulary lymphatic system A network of vessels that collects fluid from body tissues and returns it to the bloodstream; contains much of the immune system. immunization An injection that causes the body to become immune to an infectious disease; also called a vaccination. vaccine A substance containing small amounts of dead or modified pathogens or their toxins that is injected during an immunization.