Immunity & Disease

1. Immunity & Disease Disease • pathogens –Disease-causing agents, such as bacteria and viruses • have always caused illnesses. • only during the last few hundred years scientists have understood the relationship between pathogens and diseases. • Before then, little was known about disease and immunity, and superstitions were common. Note the hole in the skull in the image above. How would a hole in the head lead to more disease?

2. EARLY RESEARCH ON DISEASES During the eighteenth and nineteenth centuries, doctors learned a lot about the causes and treatment of diseases. • EDWARD JENNER • JOHN SNOW • ANTON VON LEEUWENHOEK Delete text and place photo here. Delete text and place photo here. Vaccinated Not Vaccinated First Vaccination Vaccination-a procedure that helps the body defend itself against disease. 1796- Edward Jenner developed the first vaccination fro small pox. How can we prevent people from getting small pox? Women who milked cows often got a mild disease called cowpox. These women did not get smallpox, a deadly disease related to cowpox. Jenner thought people who have had cow pox could NOT get small pox. Jenner (a doctor) cut the arm of a young boy, placed pus from a cowpox sore in the cut. Two weeks later, Jenner infected the boy with smallpox. The boy never got sick with small pox Although the smallpox vaccine saved many lives, people did not understand why or how it

3. EARLY RESEARCH ON DISEASES Connecting Disease With a Source • In the mid-1800s, people realized that there was a connection between pathogens and disease. • Cholera- a disease of the intestinal tract caused by a bacterium • Dr. John Snow • connected the disease cholera to a bacterium he found in water. • HOW? by tracking the origin of a cholera outbreak on a map Using the map Snow tracked the outbreak to a single water pump in the city of London Had the pump closed Immediately, the number of new cholera cases decreased Looked at the water and saw microscopic organisms. Concluded that these organisms caused the disease. Not everyone agreed with Snow, but people were beginning to think that pathogens did exist.

4. EARLY RESEARCH ON DISEASES One of the reasons people were slow to accept the idea of pathogens is because people could not see the pathogens. However, the development of microscopes changed that. • EDWARD JENNER • JOHN SNOW • ANTON VAN LEEUWENHOEK Delete text and place photo here. Von Leeuwenhoek Microscope Todays microscope The Development of Microscopes • Late 1600s- Anton van Leeuwenhoek (LAY vun hook) • made one of the first microscopes. • Using the microscope • observed pond water and saw moving organisms • had discovered bacteria Because he did not share how he made the lenses, bacteria were not observed again until the nineteenth century.

5. Scientist Activity Complete the thinking map using your notes Scientist Year Contribution

6. Lab Which well is contaminated? Imagine that you live in a town with four wells. You get your water regularly from one well, but sometimes you also drink water from another well. People are getting sick. Some suspect that the water in one well is causing the sickness. Which well is contaminated? Procedure 1. Take an envelope from your assigned well. Do not look inside the envelope. 2. Write your name on the envelope, and then pass it to another person from any well. You should also receive a different envelope from another person. . 3. Repeat step 2. 4. Write your name on the third envelope and open it. If there is an “X” on the card inside, the three people who signed the envelope drank from the contaminated well and are sick. As a class, compile the results in a table

7. BACTERIA

8. Connecting Bacteria to Disease . Louis Pasteur found that infection-causing bacteria came from outside the body. He developed a process called pasteurization, in which a liquid is heated to a temperature that kills most bacteria. This led to the discovery of other methods to kill bacteria, which made surgery safer.

9. Discovering Disease Organisms • Robert Koch developed a procedure to determine if a bacterium caused an illness • . • His research convinced scientists that bacteria can cause diseases.

10. Discovering Disease Organisms • Over time, scientists realized that other pathogens, such as viruses, could also cause diseases. • Pathogens can be transmitted by food, water, insects, or between people. • Diseases can be caused by pathogens, the environment, and choices you make about diet, exercise, and sleep. • They can also be inherited.

11. How Can Disease be Caused? • Diseases can be caused by pathogens, the environment, and choices you make about diet, exercise, and sleep. • They can also be inherited.

12. Why do we get diseases?

13. Types of Diseases Diseases caused by pathogens that can be transmitted from one person to another are infectious diseases. A vectoris a disease-carrying organism that does not develop the disease. A disease that cannot pass from person to person is a noninfectious disease.

14. Types of Diseases • Noninfectious diseases can be caused by genetics or environmental conditions, including lifestyle choices. • Noninfectious diseases that affect children are primarily due to genetics. • Cystic fibrosis is a disease children inherit in the form of a gene. • Cystic fibrosis is a recessive trait, which means to have the disease a person must inherit the gene from each parent.

15. Inheritance of Cystic Fibrosis Lesson 1

16. Types of Diseases • Many noninfectious diseases that affect adults are due primarily to environmental causes or life choices. • Canceris a disease in which cells reproduce uncontrollably without the usual signals to stop. • Tumors form when cells reproduce uncontrollably.

17. How do infectious and noninfectious diseases differ?

18. QUIZ tomorrow

19. Lesson 1 • How a disease spreads depends on the pathogen. Some pathogens can be transmitted by a vector, such as a tick or a mosquito.

20. Lesson 1 • The two common causes of noninfectious diseases are environmental conditions and genetics. • People might inherit forms of genes that make them more likely to develop cancer.

21. Lesson 1 Edward Jenner was the first to develop which of these? A. microscope B. vaccinations C. disease D. pasteurization

22. Lesson 1 Which of the following is a noninfectious disease? A. flu B. cancer C. chickenpox D. AIDS

23. Lesson 1 Which of these is a disease characterized by cells reproducing uncontrollably? A. cystic fibrosis B. virus C. pathogens D. cancer

24. Lesson 2 The Immune System • What does the immune system do? • How do the parts of the immune system work together? • How does the immune system interact with other body systems?

25. Lesson 2 The Immune System • allergy • immunity • active immunity • vaccination • passive immunity • inflammation • antigen • antibody • B cell • T cell

26. IMMUNE SYSTEM

27. Lesson 2 Functions of the Immune System • When pathogens get past your body’s initial barriers, your immune system has defenses to stop them from reaching the parts of your body where they can make you sick. • You can improve the effectiveness of your body’s natural prevention methods by making healthy choices such as eating healthy food, exercising, and getting enough sleep.

28. Lesson 2 Parts of the Immune System • Skin, hair, mucus, and acids are first-line defenses which help keep germs from reaching the parts of your body where they can make you sick.

29. Lesson 2 Parts of the Immune System SKIN • Your skin keeps dirt and germs from entering your body. • Sweat and acids from skin cells kill some bacteria, and natural oils make skin waterproof so you can easily wash it.

30. Lesson 2 Parts of the Immune System (cont.) HAIR • Hairs in your nose and hairlike structures called cilia trap pathogens in the upper respiratory system and move them out of your body. • The digestive system is effective at stopping pathogens that enter your body on or in the food you eat.

31. Lesson 2 Parts of the Immune System (cont.) MUCUS AND ACIDS(cont.) • The digestive system is effective at stopping pathogens that enter your body on or in the food you eat. • Stomach acids destroy many pathogens. • Mucus traps pathogens • Normal muscle contractions reverse and cause vomiting. • Normal muscle contractions speed up and remove pathogens through diarrhea

32. Parts of the Immune System (cont.) Lesson 2 • Pathogens can be moved through the circulatory system to organs that fight infections. • The nervous and circulatory systems work together to produce a fever. • The high temperature kills many pathogens and stimulates white blood cell production.

33. LAB- How do different layers of your skin protect your body? • Your skin has three layers. • The top layer, called the epidermis, is thin but tough. It helps prevent harmful microorganisms from getting into the tissues and provides physical protection. • The middle layer, called the dermis, is the thickest layer. It provides strength and elasticity. • The bottom layer, called the subcutaneous layer, insulates against heat and cold and helps cushion the skin. • In this activity, you will build a model of skin.

34. Activity • Worksheet pg 39

35. What does the immune system do?

36. Parts of the Immune System (cont.) Lesson 2 • White blood cells and inflammatory response make up your body’s second-line defenses.

37. Parts of the Immune System (cont.) Lesson 2 • Some white blood cells surround and destroy bacteria directly and others release chemicals that make it easier to kill the pathogens. • Another type of white blood cell produces proteins that destroy viruses and other foreign substances.

38. Parts of the Immune System (cont.) Lesson 2 Inflammationis a process that causes the area around an injury to become red and swollen. inflammation from Latin inflammare, means “to set on fire”

39. Lesson 2 Parts of the Immune System (cont.) The inflammatory response cleans the area of the injury and keeps the infection from spreading, enabling the damaged tissue to heal.

40. Lesson 2

41. Parts of the Immune System (cont.) Lesson 2 • Third-line defenses are specific to foreign substances. • An antigenis a substance that causes an immune response. • Proteins called antibodiescan attach to the antigen and make it useless. • Certain white blood cells, called B cells and T cells, form antibodies.

42. Parts of the Immune System (cont.) Lesson 2 • B cellsform and mature in the bone marrow and secrete antibodies into the blood. • T cellsform in the bone marrow and mature in the thymus gland, producing a protein antibody that becomes part of a cell membrane. • Antibodies match with specific antigens.

43. Lesson 2

44. Activity • Worksheet pg 38

45. Parts of the Immune System (cont.) Lesson 2 How do the parts of the immune system work together?

46. Parts of the Immune System (cont.) Lesson 2 • An allergyis an overly sensitive immune response to common antigens. • The resistance to specific pathogens is immunity. • 2 types • Passive Immunity • Active Immunity

47. Active Immunity • Your body produces antibodies in response to an antigen in active immunity. • Develop through illness or infection. • Even after an infection or illness, antibodies remain in your body. • A vaccination causes the body to develop specific antibodies that can rapidly fight a pathogen’s antigens when exposed to them.

48. Lesson 2 A vaccinationis weakened or dead pathogens placed in the body, usually by injection or by mouth.

49. Passive Immunity • Passive immunityis the introduction of antibodies that were produced outside the body. • For example, • a fetus can get antibodies from its mother • Injections of some antibodies are available for adults. • Passive immunity is temporary because the body does not continue to make these antibodies.

50. Lesson 2 The Immune System and Homeostasis The immune system works with the circulatory system and respiratory system to protect your body against invaders and maintain homeostasis.