PATHOGENS & THE IMMUNE SYSTEM!!!

1. PATHOGENS & THE IMMUNE SYSTEM!!!

2. Virus Bacteria Infectious disease Noninfectious disease Lytic cycle Lysogenic cycle Autoimmune diseases Active immunity Passive immunity Jenner Pasteur Koch’s Postulates Immune Response HIV T cells B cells Allergies Epidemiologist Culture medium Inoculation Incubation TERMS TO KNOW

3. Obj. 1 – Properties, size, & role of viruses (p. 434-435) • Virus – segments of nucleic acids contained in a protein coat • 20 nm to 250 nm (1 nm = 0.00000004 in.) • Replicate by infecting cells and using the cell to make more viruses • Cause disease in many impact • Are NOT alive… • Do not grow, do not have homeostasis, do not metabolize

4. Little Assassins: What are Viruses?

5. Obj. 1, cont. • Contain a protein coat (capsid) • Can contain DNA or RNA, but not both • Many contain a membrane (envelope) surrounding the capsid • Viruses come in many shapes • Bacteriophage – a virus that infects bacteria • Virus is Latin for poison

6. Study of Viruses

7. Obj. 2 – Reproduction of viral particles (p. 436 – 437) • Rely on living cells (host cells) for replication • Must infect a host cell (either through tiny tears or by “injecting” its DNA into the host cell – T4 bacteriophage) • Either through lytic cycle or lysogenic cycle

8. How Viruses Work

9. 5 Steps of Replication • Attachment • Injectionof genetic material • Making new parts • Assembly of parts • Release of new parts

10. AIMAR

11. Obj. 3 – Lytic & lysogenic cycle (p. 436 – 437) • Lytic Cycle – viral infection, replication, and cell destruction • Lysogenic Cycle – infect a cell, but do not make new viruses…when cell divides the virus divides also…to cause a problem the virus has to enter the lytic cycle

12. Lytic Cycle 1 2 3 4 5

14. Tetanus Food Poisoning Tuberculosis Whooping Cough Spinal Meningitis Impetigo Small pox Chicken pox Colds Influenza AIDS Mumps Rabies Herpes Hepatitis Warts Obj. 4 – Common human viral and bacterial diseases (p. 440-447)

15. VIRAL DISEASES

16. Viruses Throughout History

17. BACTERIAL DISEASES

18. BACTERIAL SHAPES

19. VIRUSES

20. VIRUSES, CONT.

21. Obj. 5 – How do bacteria cause disease? (p. 447 – 448) • Simply…bacteria are in competition with your body for the resources that you need to live

22. Obj. 15 – Jenner and Pasteur (p. 931) • Edward Jenner, English Doctor…. • Invented vaccine • Infected own son with cow pox (a mild form of small pox) • Son didn’t contract small pox • Cow pox triggered immune system to create an immunity against small pox

23. Obj. 15, cont. • Louis Pasteur • Pasteurization • Disproved spontaneous generation • Said “life came from life” • Boiled broth to kill microorganisms

24. Obj. 16 – What is an epidemiologist? (p. 457) • A scientist who studies the causes and controls of disease outbreaks. • Involved in preventing disease outbreaks and in stopping outbreaks that do occur spreading. • Work for CDC, FBI, etc.

25. Influenza of 1918

26. Vaccines & Treatment of Viruses

27. Obj. 17 – Inoculation & Incubation of culture medium • Culture medium – either a broth or an agar with nutrients added to it to aid in the growth of microorganisms. • Inoculation – referred to as a streak or stab (putting microorganisms in a nutrient agar or broth so they can grow) • Incubation – usually 24 – 48 hours at a temperature of 20º C or 37º C.

28. Inoculation Technique Heat loop Inoculation

29. Inoculation Broth Inoculation Slant

30. Agar Plate Agar Deep

31. Streak Plates

33. Finished Product

34. Obj. 18 – Koch’s Postulates (p. 930) • The pathogen must be found in an animal with the disease and not in a healthy animal. • The pathogen must be isolated from the sick animal and grown in a laboratory culture. • When the isolated pathogen is injected into a healthy animal, the animal must develop the disease. • The pathogen should be taken from the second animal and grown in a laboratory culture. The cultured pathogen should be the same as the original pathogen.

35. Obj. 6 – Infectious v. Noninfectious diseases (p. 924) • Infectious disease - Any disease caused by the presence of pathogens in the body • Easily spread from one person to another or from one body part to another • Non-Infectious disease - One that does not spread • Rheumatoid arthritis

36. Mutations in Viruses

37. Obj. 7 - How is disease spread? • People – Direct contact • Touching • Kissing • Sexual contact • Object – food poisoning • Air, Soil and Water • Vectors – insects: malaria

38. Polio Panic

39. Pathogen – disease causing organisms • Virus • Bacteria • Fungi • Protozoans

40. Obj. 10 – Immune response (p. 926 – 929) • Immunity - Building up resistance • Immunity occurs when system recognizes a foreign substance and responds by production of special lymphocytes which produce antibodies • After recovery, if infected again, won’t get sick because defense mechanisms are in place

41. Obj. 8 – T cells and B cells (p. 927 – 929) • Both are white blood cells • Regulated by helper T cells • B cell response – defense that aids the removal of extracellular pathogens • B cells • Stay in lymph nodes & organs • Mature in bone marrow • T cell response – destruction of intracellular pathogen by cytotoxic T cells • Both lymph, organs & circulation • Occur in thymus gland (located in lower neck & thorax) • Act directly against certain pathogens

42. Obj. 9 – Specific v. Nonspecific (p. 924-929) • Nonspecific – always present, fights off anything foreign to the body. • 2 lines of defense (1 outside, 1 inside) • Specific – body has been exposed to disease before (immunity to chicken pox once you have already had the disease)

43. Obj. 9, cont. • 1st line of nonspecific defense • Mucous membranes – traps it before it can enter the body • Skin – acts as a physical barrier • Sweat – contains lysozyme (which digest bacterial walls) • 2nd line of nonspecific defense • Inflammatory response • Temperature response • Proteins • White blood cells

44. Obj. 9, cont. • Temperature response • Disease causing bacteria don’t grow well at high temperatures • Normal body temperature 37º C (98.6º F) • > 39º C (103º F) – dangerous • >41º C (105º F) - fatal

45. Obj. 9, cont. • Inflammatory response

46. Obj. 9, cont. • Protein complement system • About 20 different proteins circulate in the blood and became active when they encounter certain pathogens by attaching to the surface of proteins and damaging plasma membrane. • Interferons • Protein is released by cells infected with virus which causes nearby cells to produce an enzyme that prevents viruses

47. White blood cells – patrol the bloodstream-wait to attack the pathogen • Neutrophils – engulf bacteria, then release chemicals that kill bacteria, can also squeeze between cells in the walls of capillaries to attack pathogens. • Macrophage – ingest & kill bacteria and clear dead cells & other debris, travel through the body in lymphatic systems and & between cells, concentrated in particular organ (spleen and lungs) • Natural killer cells – attack cells infected with pathogens, puncture cell membrane, water rushes into infected cell which swells & burst (body’s defense against cancer)

48. Obj. 9, cont. SPECIFIC RESPONSE • White Blood Cells – produced in bone marrow and circulate in the blood and lymph nodes • Macrophage – consume pathogens and infected cells • Cytotoxic (killer) T cells – attack & kill infected cells • B cells – label invaders for later destruction by macrophages • Helper T cells – activate cytotoxic T cells & B cells

49. Obj. 9, cont. • Infected cell has an antigen (substance that triggers an immune response) of an invader on its surface • White blood cells are covered with receptor proteins that respond to infection by binding to specific antigens on the surfaces of the infecting microbes • They recognize and bind to antigens that match their particular shape.

50. Obj.11 – Active v. Passive immunity (p. 930 – 932) • Immunity – resistance to a particular disease • Active immunity - immunity that you get because you have been exposed to a disease • Passive immunity – immunity that you get because of a vaccine