Body Defenses, Immunity, and Vaccines

1. Body Defenses, Immunity, and Vaccines B&S CH 17

2. Immune System • This is the system that fights harmful organisms and invaders • The immune system is made up partly of the lymph system and of specific fighting cells

3. Immune System • Bugs, strep, viruses all enter the body some how. Certain bugs enter the body a certain way for example: • The cold virus (which ever strand it is) likes to leave one person through sneezing or a kleenex and enter another person through their nose or by being inhaled and enter through mucous membranes

4. Portal of Entry • We discussed this earlier • Resp. tract is most common entrance route for pathogens • Digestive system and tubes into the urinary tract, or a break in the skin are other ways bugs enter the body

5. Virulence • How aggressive or powerful is the bug • Does it produce toxins that are poisons that damage the body • Different organisms vary in virulence • Organisms can change and may gain more virulence as they pass from one infected host to another

6. Dose • This refers to the # of pathogens • If the troops are big in #, it will take more fighting to get rid of them

7. Predisposition of host • Is the person or host in good condition emotionally, physically, these include living habits and age

8. Line of defense • These are the features that protect the body against disease beginning with the simple outer barriers and proceeding through progressively more complicated responses until the ultimate defense mechanism of immunity, is reached

9. Line of Defense • SKIN – serves as a mechanical barrier against invaders through the skin • Burn pts are at serious risk for infections if they don’t have that protective coat

10. Mucous Membranes – keep germs out by causing the germs to stick to the mucous. Cilia in the membrane also help sweep debris and keep it from getting in

11. Body Secretions – like tears, perspiration, and saliva, wash away microorganisms or kill it off because these body fluids contain acid, enzymes or other chemicals that are good at destroying invaders

12. Phagocytosis • This is the 2nd line of defense against invaders • WBC’s invade the bad spot and destroy waste and foreign materials

13. The main Phagocytic WBC • Neutrophils – (granular leukocytes) • Macrophages – • Both of these blood cells travel in the blood to the sites of infection • Some macrophages remain fixed in a certain part of the body like in the skin, liver, lungs, lymphoid tissue, bone marrow to do a specific job

14. Natural Killer Cells • This is a different type of lymphocyte • Natural Killer cells can recognize body cells with abnormal membranes such as in tumor cells or in cells infected with virus • Natural Killer cells destroy the bad cells on contact

15. Inflammation • Is the body’s effort to get rid of anything that irritates it • Friction, fire, chemicals, x-rays, cuts or blows can all be classified as irritants • If the irritant is d/t pathogenic invasion, the resulting inflammation is called “infection”

16. Inflammatory Reaction • With the entrance of a pathogen, a whole series of defensive processes begins: • 4 classic symptoms • 1. heat • 2. red • 3. swelling • 4. pain

17. Histamine • When tissues are injured, histamines are released from the damaged tissue causing small blood vessels to widen or dilate • More blood then flows to that area resulting in the 4 classic symptoms: • 1. runny nose, sneezing • 2. hypotension • 3. swelling of tissue • 4. hives

18. With the increase of blood flow comes a vast # of leukocytes and now something new happens… • Now, the walls of the tiny blood vessels become coarsened in texture just like a piece of cloth when it is stretched • Blood flow slows down, leukocytes move through these altered walls and into tissue where they can get at the irritant directly • The whole clotting cascade starts, fluids leak out of the vessels from the blood plasma and begins to clot

19. Inflammatory exudate • Is the mixture of fluid and leukocytes, this fluid causes pressure on nerve endings • This extra fluid and the increased amt of blood in the vessels is why we feel pain from inflammation

20. Pus • As phagocytes do their work, they die off rapidly • The area around the injury eventually becomes filled with dead leukocytes • The mixture of exudate, living and dead blood cells, pathogens and destroyed tissue is now called “PUS”

21. Lymphatic System • Now the lymphatic system begins to drain fluid from the inflamed area and carry it toward the lymph nodes for filtration • The regional lymph nodes near the injury become enlarged and tender which is a sign that they are performing their protective function by producing phagocytic cells to “clean” the lymph flowing through them

22. Fever • When your body temperature rises above normal, this can be a sign that body defenses are at work • When phagocytes are exposed to infecting organisms, they release substances that act to raise body temperature

23. Fevers • Fever boosts the immune system in many ways: • Fever: • Stimulates phagocytes • Increases metabolism • Decreases the ability of certain organisms to multiply

24. Fevers • Are normal reaction of the body during infection or invasion of some organism • Advertisers make people believe that fevers are “BAD” and that they should always be eliminated • We need fevers to help us to get better and to also warn us of some pathogen that has entered the body

25. How to treat fevers • Acetominophen (Tylenol) • Children: 10-15mk/kg Q 4hr (Don’t be afraid to give the max amount) • Adults: 325-650mg Q 4 hr • P.O. P.R.

26. Ibuprofen – Advil, Motrin • Children: 10mg/kg Q 6hr • Adults: 200-800mg Q 6-8-12 hrs depending on what dose was given • P.O.

27. Interferon • cells infected with viruses and certain other agents produce a substance that prevents the infection of other cells, this substance is called “interferon” • Interferon is now known to stimulate the immune system • Is now used to boost the immune system in the treatment of malignancies and infections

28. Immunity • Can be defined as the power of an individual to resist or overcome the effects of a particular disease or harmful agent

29. IMMUNITY • Immunity is the final line of defense against disease • It is a selective process meaning that immunity to one disease does not necessarily cause immunity to another • This selective characteristic is known as “specificity”

30. 1. Inborn immunity - this is inherited along with other characteristics in a person’s genes 2. Acquired immunity – develops after birth, this one you “get after you are born” when you get immunizations 2 Main Categories of Immunity

31. Inborn Immunity • This is just like the jewish culture that gets polycthemia or the african american culture that get sickle-cell….you are born with the ability to be immune to certain things

32. Species immunity • (This is a form of inborn immunity) • Animals only have distemper, we cannot get this • Hogs only have hog cholera, we cannot get this • This is also how our inborn immunity works, usually, we can only get what is within out gene pool

33. Population Immunity • (This is another form of inborn immunity) • Some groups have a greater inborn immunity to certain diseases than others • In Europe, measles is a mild disease, in the Pacific Islands, it is fatal. The foreigners brought it there. The Pacific Islanders had not yet developed a genetic resistance to the disease over time and it was too much, too fast

34. Polio and malaria • In the U.S., these are public threats • American blacks were more resistant to polio than whites, it affected white more • Some populations are more resistant to malaria or yellow fever than are other populations • You cannot tell who is resistant and who is not until these diseases are studied

35. Individual Immunity • Herpes I - these are cold sores, some people are immune it seems and can come in contact with a cold sore and they don’t get it, others just look at it and they get one (not really)

36. Why do some people live longer than others • Some 98 year old can live the perfect most healthy life for 98 yrs and never get anything really bad • Another person may have drank, smoked, ate horribly and also has lived to be 98 yrs old…why? • Perhaps the 2nd person had better immunity that she was born with to fight off infections and other harmful things

37. Acquired Immunity • You get immune over your life time by getting 350 million cold strands and building immunity or by getting the flu shot and building immunity to that same strand • Getting vaccinations against chicken pox, MMR so you won’t get it full blown

38. Active – you actually have to have contact with the disease and then you can build immunity to it. Getting a flu shot, vaccine or a cold Or Passive – this is usually passed on to a person like to a baby in mom’s breast milk. Lasts 6 months in a new born and then they build their own Acquired immunity may be…

39. Artificially acquired immunity • Rhogam injection, mom gets it after birth, she will build it up and artificial = the injection…she didn’t make it herself

40. Antibody • Is also known as an immunoglobulin • This is found in the part of the plasma called gamma globulin • Gamma gard or gamma globulin or IVIG is a gammaglobulin that is given to pts who need immunity such as in • All antibodies are immunoglobulins • There are several immunoglobulins…

41. Antibody • Its purpose is to fight off the antigen using all of the body’s immunity like all of the gammaglobulins…

42. Antibodies • IgG- this is given to baby by mom for general immunity • IgA • IgD • IgM • IgE • Our body has these and they fight specific things for example: • IgE attaches to mast cells in the resp. tract and plays a major role in allergic reactions

43. IVIG, Gamma gard • Or “gamma globulin” is a gammaglobulin that is given to pts who need immunity such as in thrombocytopenic pts, cancer pts, hepatitis A and B pts

44. Antigen • Not your blood type in this case… • This is any foreign substance that enters the body and induces or starts up an immune response • Most antigens end up being large protein molecules, sometimes they can be carbohydrates or lipids

45. Antigens • May be found on: • the surface of pathogenic organisms • The surface of RBC’s • On tissue cells • On pollens • In toxins • In foods

46. What do antigens for the body? • They stimulate the activity of certain lymphocytes called “T” or “B” cells, which are needed in immunity and to fight the antigen off

47. T and B Cells • Both come from the bone marrow • T cells migrate to the Thymus to become mature lymphocytes • T cells cannot recognize foreign antigens without the help if the macrophage which engulfs the foreign object and identifies it.

48. B cells • Are antigen specific and will only attack certain foreign proteins • B cells are usually found in the spleen and lymph nodes • B cells make a picture or memory cell of the foreign protein that just entered the body so it can destroy it when it sees it again

49. T and B cells • Are needed to fight foreign invaders, they will invade whatever foreign protein enters the body the 2nd time it enters • The 1st time a foreign protein enters, pictures are taken and the next time, BOOM!!!! The body fights that protein off

50. Vaccines • Can be made with live organisms, but the organism must be weakened in a lab first to take away some of the virulence. This is called “attenuated” • Can be made with dead organisms that are killed by heat or chemicals