Notes - Disease and the Immune System.ppt


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Notes - Disease and the Immune System.ppt

  1. 1. Disease and the Immune System
  2. 2. <ul><li>Disease </li></ul><ul><ul><li>is any change, other than an injury, that disrupts the normal functioning of the body. It is the inability to maintain homeostasis. </li></ul></ul>
  3. 3. Causes <ul><li>Inheritance : sickle-cell anemia, hemophilia </li></ul><ul><li>Toxic Substances : cigarette smoke, alcohol </li></ul><ul><li>Poor Nutrition : ricketts, anorexia, scurvy </li></ul><ul><li>Organ Malfunction : heart disease, diabetes </li></ul><ul><li>Personal Behavior : drug addiction, alcoholism </li></ul>
  4. 4. Causes continued <ul><li>Pathogens : organisms that enter the body and cause infectious diseases </li></ul><ul><li>Antigens </li></ul><ul><ul><li>Toxins that pathogens produce that cause harm to an organism. </li></ul></ul><ul><ul><li>Virus </li></ul></ul><ul><ul><ul><li>Protein shell </li></ul></ul></ul><ul><ul><ul><li>DNA or RNA </li></ul></ul></ul>
  5. 5. Examples of Viruses
  6. 6. <ul><ul><li>Virus uses the host cell to reproduce </li></ul></ul>
  7. 7. <ul><li>Examples of diseases caused by viruses: mono, flu, common cold, chicken pox, small pox, pertussis, AIDS </li></ul>AIDS small pox chicken pox
  8. 8. <ul><li>Pathogens continued: </li></ul><ul><ul><li>Bacteria : Tuberculosis, E. coli, cholera, tetanus </li></ul></ul>tuberculosis E. coli cholera tetanus
  9. 9. <ul><li> c) Fungi : ringworm, athlete’s foot, jock itch </li></ul>ringworm athlete’s foot
  10. 10. <ul><ul><li>d) Parasites : lice, malaria, dysentery, tapeworm, schistosomiasis </li></ul></ul>lice malaria in red blood cells Amoebic dysentery tapeworm schistosomiasis
  11. 11. What is Immunity?
  12. 12. Immunity <ul><li>Immunity </li></ul><ul><ul><li>The ability of the body to fight infection and/or foreign invaders by producing antibodies or killing infected cells. </li></ul></ul><ul><li>Immune System </li></ul><ul><ul><li>The system in the body responsible for maintaining homeostasis by recognizing harmful from nonharmful organisms and produces an appropriate response. </li></ul></ul>
  13. 13. Parts of the Immune System <ul><li>Blood - White Blood Cells in particular. </li></ul><ul><li>Lymph nodes </li></ul><ul><li>Thymus Gland – Produces T Lymphocytes </li></ul><ul><li>Bone Marrow – Produces B Lymphocytes </li></ul>
  14. 14. How does the body fight infection/foreign invaders? <ul><li>The Body’s THREE lines of Defense </li></ul><ul><li>First Line of Defense – The Skin </li></ul><ul><ul><li>Provides Physical and Chemical barriers </li></ul></ul><ul><ul><ul><li>Physical – hard to penetrate, made of indigestible keratin </li></ul></ul></ul><ul><ul><ul><li>Chemical – tears, sweat </li></ul></ul></ul>
  15. 15. Second Line of Defense – Nonspecific Immune Response <ul><li>These are defenses the body uses no matter what the invader may be. These defenses include: </li></ul><ul><ul><li>Phagocytosis – done by Macrophages </li></ul></ul><ul><ul><li>Natural Cell Killers </li></ul></ul><ul><ul><li>Inflammation - caused by release of Histamine from leukocytes </li></ul></ul><ul><ul><li>Fever – caused by histamines. The fever (high temp) kills invaders by denaturing their proteins. </li></ul></ul>Macrophage : A phagocytic cell found in the liver, spleen, brain and lungs. Travels to all areas of the body to find and eat pathogens.
  16. 17. <ul><li>This is a specific response to a specific pathogen/antigen. </li></ul><ul><li>The response involves the creation of Antibodies. </li></ul>Third Line of Defense – Specific Immune Response
  17. 18. Antibodies <ul><li>Y-shaped protein molecule. </li></ul><ul><li>Made up of variable and constant regions. </li></ul><ul><li>Made up of Heavy and Light chains. </li></ul><ul><li>Produced by B-Lymphocytes </li></ul><ul><li>Function: Recognize antigens, bind to and deactivate them. </li></ul><ul><ul><li>Note: Variable region recognizes the anitgens. </li></ul></ul>
  18. 19. How an antibody operates/works? Deactivation of a bacterium by an antibody.
  19. 20. The Pathway of Specific Immune Response Pathogens Pathogens eaten by Macrophage Displays portion of Pathogen on surface Helper-T cell recognizes Pathogen Step 1 Step 2 Step 3
  20. 21. Activates B- Cell Activates Cytotoxic T- Cell Memory B-Cell Memory T-Cell Kills Infected Cells Antibodies 
  21. 22. Cellular Immunity .vs. Antibody Immunity <ul><li>Carried out by T-Cells </li></ul><ul><li>Infected cells are killed by Cytotoxic T –Cells. </li></ul><ul><li>Carried out by B-cells </li></ul><ul><li>Antibodies are produced and dumped into blood stream. </li></ul><ul><li>Antibodies bind to antigens and deactivate them. </li></ul>Cellular Immunity Antibody or Humoral Immunity
  22. 23. Immune Response Explained <ul><li>Antigen infects cells. </li></ul><ul><li>Macrophage ingests antigen and displays portion on its surface. </li></ul><ul><li>Helper T- Cell recognizes antigen on the surface of the macrophage and becomes active. </li></ul><ul><li>Active Helper T-Cell activates Cytotoxic T-Cells and B-Cells. </li></ul><ul><li>Cytotoxic T-Cells divide into Active Cytotoxic T-cells and Memory T – Cells. </li></ul><ul><li>Active Cytotoxic T-Cells kill infected cells. </li></ul><ul><li>At the same time, B-Cells divide into Plasma Cells and Memory B- Cells. </li></ul><ul><li>Plasma cells produce antibodies that deactivate pathogen. </li></ul><ul><li>Memory T and Memory B cells remain in the body to speed up the response if the same antigen reappears. </li></ul><ul><li>Suppressor T-Cells stop the immune response when all antigens have been destroyed. </li></ul>
  23. 24. Immune Response Summary Displays copy of antigen on surface of cell Cellular Immunity Antibody Immunity Antigen Macrophage Helper T - Cell Active Cytotoxic T-Cell Active B - Cell Kills Infected Cells Memory T- Cell Plasma Cell Memory B-Cell Antibodies Deactivates Antigens
  24. 25. Primary .vs. Secondary Immune Response <ul><li>Primary Immune Response </li></ul><ul><ul><li>This is a response to an invader the First time the invader infects the body. </li></ul></ul><ul><ul><ul><li>No measurable immune response for first few days. </li></ul></ul></ul><ul><ul><ul><li>Next 10 – 15 days antibody production grows steadily </li></ul></ul></ul><ul><li>Secondary Immune Response </li></ul><ul><ul><li>A more rapid response to an invader the 2 nd time it invades the body. </li></ul></ul><ul><ul><ul><li>Antibody production increases dramatically and in a much shorter time period.. </li></ul></ul></ul>
  25. 26. Primary .vs. Secondary Immune Response
  26. 27. Passive .vs. Active Immunity <ul><li>Active Immunity </li></ul><ul><ul><li>This is immunity where the body is “actively” producing antibodies to fight infection. </li></ul></ul><ul><ul><li>Ex: You have a throat infection and you are actively creating antibodies to fight it. </li></ul></ul><ul><ul><li>Vaccination: An injection of a weakened strain of an infectious microbe (pathogen) that causes the body to undergo active immunity (produce antibodies). </li></ul></ul><ul><li>Passive Immunity </li></ul><ul><li>This is immunity where antibodies are given to a person from the blood of another person or animal. </li></ul><ul><li>This immunity only lasts for a short period of time. </li></ul><ul><li>ex: Breastfeeding mothers pass antibodies to their children through the milk. </li></ul><ul><li>ex: Vaccines against tropical diseases like cholera & typhoid </li></ul>
  27. 28. Man-made treatments for diseases <ul><li>Antibiotics </li></ul><ul><ul><li>Produced by certain organisms that destroy bacteria. Can slow down reproduction </li></ul></ul><ul><ul><ul><li>Ex. Penicillin, made from a kind of mold, interferes with the production of the cell walls of the bacteria </li></ul></ul></ul><ul><ul><li>Cannot be used against viruses . Some drugs can be used that interrupt the viruses life cycle, so prevents virus from entering the host cells. </li></ul></ul>
  28. 29. Autoimmune Disease <ul><li>Autoimmune diseases are diseases where the immune system begins to attack itself. </li></ul><ul><ul><li>Ex: </li></ul></ul><ul><ul><ul><li>Rheumatoid Arthritis – crippling disease of the joints. </li></ul></ul></ul><ul><ul><ul><li>Lupus – disease of blood and organs. </li></ul></ul></ul><ul><ul><ul><li>Multiple Sclerosis – disease of nervous system </li></ul></ul></ul><ul><li>Cause(s): unknown </li></ul><ul><li>Cures/Treatments: No known cures. Usually treated with drugs. </li></ul>
  29. 30. Allergies <ul><li>Allergy </li></ul><ul><li>- An exaggerated response by the immune system to an allergen. </li></ul><ul><li>Allergen: a normally harmless substance that causes an allergic reaction. </li></ul><ul><li>ex: dust, pollen, mould, food, insect stings </li></ul><ul><li>Types of Allergic reactions </li></ul><ul><li>There are two types of allergic reactions. </li></ul><ul><li>a. Immediate – occurs within seconds and normally lasts for about 30 mins. </li></ul><ul><li>b. Delayed – takes longer to react and can last for a much longer time. </li></ul>
  30. 31. What happens during an allergic reaction? <ul><li>During an allergic reaction antibodies cause histamines to be released from certain cells. </li></ul><ul><li>Histamines cause: </li></ul><ul><li>a. Swelling of tissues </li></ul><ul><li>b. Release of fluids (runny noses and eyes) </li></ul><ul><li>c. muscle spasms (some cases) </li></ul><ul><li>Anaphylaxis or anaphylactic shock: </li></ul><ul><li>This is the sudden and severe allergic reaction to a substance that can cause death. </li></ul><ul><li>Treatments for Allergies </li></ul><ul><li>Avoidance of material – especially food. </li></ul><ul><li>Epinephrine – “epi – pen” </li></ul><ul><li>Antihistamines -- benadryl </li></ul>
  31. 32. HIV and AIDS HIV particles (grey) covering a white blood cell. This Powerpoint is hosted on Please visit for 100’s more free powerpoints
  32. 33. HIV History <ul><li>HIV is thought to have entered into humans somewhere between 1914 and 1940. </li></ul><ul><li>In 1983, a retrovirus, now called human immunodeficiency virus (HIV), had been identified as the cause of AIDS. </li></ul><ul><li>The HIV antibody test has be used to screen all blood supplies in the U.S. since 1985. </li></ul><ul><li>People receiving blood or blood products before 1985 may have been infected. </li></ul>
  33. 35. HIV H uman I mmunodeficiency V irus <ul><li>HIV infects the immune system cell called the Helper T cells (-most important white blood cell involved in identifying infections.) </li></ul>
  34. 36. AIDS A cquired I mmune D eficiency S yndrome <ul><li>The immune crippling disease caused by the HIV virus in which the body becomes unable to protect itself against any secondary infections. </li></ul>
  35. 37. Body Fluids with High Concentrations of HIV <ul><li>Blood </li></ul><ul><li>Semen/Vaginal fluids (as high as blood) </li></ul><ul><li>Breast milk </li></ul><ul><li>Pus from sores </li></ul>
  36. 38. Low concentrations of HIV <ul><li>It is highly unlikely you will be infected if you come into contact with: </li></ul><ul><li>Sweat </li></ul><ul><li>Tears </li></ul><ul><li>Urine </li></ul><ul><li>Saliva (-highly possible if blood from mouth sores is present) </li></ul>
  37. 39. How is HIV Spread? <ul><li>ANY type of sexual activity (highest risk) </li></ul><ul><li>Sharing used drug needles </li></ul><ul><li>Pregnancy-from mother to child </li></ul><ul><li>Sharing razors- if blood is present </li></ul><ul><li>Kissing- if even the smallest amount of blood is present. (-membranes of mouth are thin enough for HIV to enter straight into the body.) </li></ul><ul><li>Tattoos/body piercing if equipment is not clean. </li></ul>
  38. 40. How is HIV not spread? <ul><li>Shaking hands </li></ul><ul><li>Hugging </li></ul><ul><li>Swimming pools </li></ul><ul><li>Toilet seats </li></ul><ul><li>Insect bites </li></ul><ul><li>Donating blood </li></ul>
  39. 41. Can HIV be cured? <ul><li>NO! Drugs are available to manage the disease, but HIV stays in the body forever! </li></ul><ul><li>PROBLEM : RNA viruses mutate at a very high rate. A person with HIV under control can evolve resistance to the drug treatments. </li></ul><ul><li>Some infected persons have several strains of HIV in their bodies. </li></ul>
  40. 42. What does HIV look like? <ul><li>Initial infection- flu like symptoms a few weeks after infection. </li></ul><ul><li>Stage 1-HIV positive with no symptoms- can stay at this stage for up to 10 years, but still can pass on the virus. </li></ul><ul><li>Stage 2-HIV positive with symptoms- at this point the person is said to have AIDS . Symptoms include: </li></ul><ul><ul><li>swollen glands, chronic diarrhea, loss of weight and appetite, fever, fatigue, skin rashes (lesions), night sweats, oral thrush. Life expectancy: 2 to 5 years. </li></ul></ul>
  41. 43. Death and AIDS <ul><li>Stage III-Full blown AIDS- </li></ul><ul><ul><li>Person dies of rare opportunistic infections that take advantage the weakened immune system: </li></ul></ul><ul><ul><li>Person dies in a matter of months. </li></ul></ul><ul><ul><li>AIDS related illnesses include rare cancers and Pneumonia. </li></ul></ul>
  42. 44. Stages of HIV Infection