2. The Immune System “Infection Protection” How the body protects itself from disease Chapter 10 (10-2)

3. Blood Blood is a liquid tissue with 3 functions: 1. Transportation 2. Regulation 3. Protection We have between 4-6 L of blood

4. Purpose of Blood l Transport l Regulation l Protection

5. Purpose of Blood Transport: l To carry nutrients to all cells l To carry wastes away from cells to removal organs l To carry hormones (chemical messengers)

6. Purpose of Blood Regulation l To absorb heat from one part of the body and release it in a cooler part. l To maintain pH and water levels.

7. Purpose of Blood Protection l To defend the body against disease- causing agents. l To stop the body from bleeding by clotting.

8. Components of Blood l Plasma l Erythrocytes or Red Blood Cells l Leukocytes or White Blood Cells l Platelets

9. Components of Blood

10. Plasma l Water – 90% l Dissolved Material such as: salts, glucose, amino acids, fatty acids, vitamins, hormones, wastes l Proteins Albumin – regulates movement of water out of blood Fibrinogen – involved in clotting Globulins – many functions such as: Transport Proteins – to move substances Antibodies – to destroy foreign substances and fight disease.

11. Red Blood Cells Erythrocytes l Carry oxygen and carbon dioxide l Made in the bone marrow l 30 trillion in the body l Does not contain a nucleus l Contains hemoglobin – an iron- containing protein that causes it to be red and to carry oxygen

12. Red Blood Cells Erythrocytes l Fun Facts: You have 30 trillion RBCs They live 120 days – then get destroyed. New cells are formed at the rate of 2 million per second (same rate they die) The liver and spleen removed dead cells and the iron is recycled.

13. Anemia When you have too few RBCs or not enough hemoglobin (low iron in diet). Symptoms: not enough oxygen in blood, you get very tired. Treatment:Eat more iron, get shots of vitamin B-12 for pernicious anemia.

14. Sickle Cell Anemia l Genetic Disorder – when RBCs are not formed correctly because hemoglobin is made wrong: Symptoms: RBCs are sickle in shape and get stuck in blood vessels causing pain. Treatment: Transfusions help.

15. Sickle Cell Anemia

16. White Blood Cells Leukocytes l Colorless blood cells l Defend the body from bacteria and viruses l Made in the bone marrow l Have a nucleus. l They can move on their own or carried by the blood stream. l There are five different kinds of WBCs.

17. Five types of White Blood Cells Neutrophils – phagocytosis of small particles Monocytes – phagocytosis of large particles Eosinophils – release clot-digesting agent, combat allergy-causing substances Basophils – release heparin – anti-clotting agent, and histamine – that causes inflammation Lymphocytes – produce antibodies that are involved in the immune response

18. White Blood Cells Leukocytes l Fun Facts: You have 60 billion white blood cells. They are made at a rate of 1 million per second. When you have an infection they multiply and congregate in the area of the infection to attack the invader. Pus that forms contains WBCs and bacteria.

19. Leukemia A type of cancer that produces white blood cells. l Symptoms include very high WBC count. l Treatment: includes bone marrow transplants and medications.

20. Platelets l Cell fragments involved in blood clotting. l Form by pinching off bits of cytoplasm from large cells in the bone marrow. l Do not contain a nucleus. l Surrounded by a membrane.

21. Platelets l Fun Facts You have 1.5 trillion platelets They live for 7 days They are produced at a rate of 200 billion a day.

22. Blood Clotting l Good Clotting - helps you to stop bleeding when you have an injury. l Bad Clotting – when you get a clot within a blood vessel that clogs the vessel. You can have a stroke or heart attack from this. l The process is basically the same…

23. Blood Clotting Blood Clotting Video

24. Blood Clotting 1. Platelets stick to the damaged vessel and break. 2. Broken platelets release thromboplastin. 3. Thromboplastin converts prothrombin to thrombin. 4. Thrombin converts soluble fibrinogen to insoluble fibrin. 5. Fibrin forms a web to stop the bleeding.

25. Blood Clotting

26. To remove clot l The body activates the enzyme plasmin to dissolve the clot after the skin heals. l The body prevents internal clots by: Having smooth vessels – platelets don’t get stuck and break. Anticoagulants (heparin) in blood prevent clotting.

27. Clotting Problems l Internal clots form when the vessels are not smooth – caused by build-up of material in veins and arteries. Symptoms: Can cause death, strokes, heart attacks if it blocks blood flow. Treatment: Heparin can be injected to dissolve the clot if done quickly.

28. Hemophilia Genetic disease where a person is missing one or more clotting factors. Symptoms – internal or external bleeding without ability to clot. Treatment – injections of missing factors, blood transfusions.

29. Blood Clotting http://www.youtube.com/watch?v=HFNWG Cx_Eu4&feature=player_embedded

30. What Causes Disease? l Viruses and bacteria are pathogens. l Pathogens are microorganisms that cause disease. l Pathogens are everywhere; in food, in air, in water, inside your body.

31. Our Immune System has three lines of defense. How Can We Protect Ourselves From Pathogens?

32. First Line of Defense Physical Barriers prevent entrance of pathogens or trap them and washes them away. Skin membranes mucus sweat urine Chemical Barriers kill or inhibit pathogen activity. Stomach acid tears saliva

33. Second Line of Defense l If a pathogen gets past first line of defense, it starts an infection. l This activates the second line of defense to have an inflammatory response.

34. Inflammatory Response Symptoms: Swelling, pain, warmth, redness Cause of Symptoms: l Cells that got damaged by infection release chemicals. l These chemicals cause more blood to flow to area,which causes symptoms. l Macrophages (large white blood cells) come to the area to ingest bacteria.

35. As Inflammatory response continues... l Pus forms from mixture of dead cells, white blood cells, bacteria and body fluid. l If pathogen is a virus, damaged cells produce interferon that protects other cells from damage.

36. Third Line of Defense l If inflammatory response is insufficient, the immune system takes over. l The immune system creates antibodies and other specialized cells to stop pathogens. l Each antibody or specialized cell is made for a specific pathogen.

37. The Immune Response (The Immune System) l Provides immunity to pathogens l Requires that the body can distinguish between “self” and foreign material. l Involves production of antibodies and specialized cells. l Is triggered by an antigen.

38. Lymphocytes Cells that recognize antigens and either a) produce antibodies b) kill foreign cells Types of lymphocytes a) B cells b) T cells

39. Type of Immune Responses Primary Immune Response l The first time you are exposed to antigen. l No antibodies for first five days. l Over the next 10-15 days rise in antibodies. Secondary Immune Response l Second exposure to same antigen. l Within 1-2 days high levels of antibodies are in blood.

40. Type of Immune Responses

41. B Cells and Antibodies l B cells are stimulated by helper T cells when they see a bacterial antigen. l Helper T cells only recognize antigen after it is ingested by a phagocyte and has been displayed on phagocyte’s membrane. l B cells then produce plasma cells and memory B cells. l Plasma cells make antibodies. l Memory B cells divide to make more plasma cells without needing helper T cells – secondary response.

42. T Cells and Antibodies l T cells are stimulated by helper T cells when they see a virus-infected cell (antigen). l Helper T cells only recognize antigen after it is ingested by a phagocyte and has been displayed on phagocyte’s membrane. l T cells then produce killer T cells and memory T cells. l Killer T cells seek and destroy antigen. l Memory T cells produce killer T cells without needing helper T cells – secondary response.

44. Suppressor T Cells l Shut down the killer T cells when the infection is stopped.

45. Types of Immunity Active Immunity l Body produces its own antibodies or killer T cells l Results from having the disease. l Results from use of vaccines containing dead or weakened virus. Passive Immunity l Body receives antibodies from a source l Results from receiving antibodies from mother’s milk. l Results from vaccine containing only antibodies

46. Blood Types l Antibodies play a part in blood types, transfusions, and transplants. l There are four different blood types: A, B, AB, and O. l You are a certain blood type if your blood contains certain antigens.

47. ABO Blood Types There are two antigens: A and B l If you have blood type A, you have A antigens and B antibodies. l If you have blood type B, you have B antigens, and A antibodies. l If you have blood type AB, you have both A and B antigens and no antibodies. l If you have blood type O, you have neither antigen and both A and B antibodies.

48. Transfusions A blood recipient cannot have antibodies to the antigens he is receiving. Example: If you have A blood, you cannot safely receive B or AB blood because you have B antibodies.

49. Challenge l Which blood type can give blood to anyone? l Which blood type can receive blood from anyone?

50. Universal Blood Donor A person with blood type O is called the universal donor. Why? Answer: His blood contains no antigens so no one will react to it.

51. Transplants l Transplanted organs trigger the recipient’s immune system to fight these foreign cells - called rejection l To control this effect, the immune system is often suppressed prior to transplant through medications.

52. Universal Blood Recipient A person with blood type AB is the universal recipient. Why? Answer: His blood contains both antigens and no antibodies, so his blood will not react to any blood type.

53. AIDS l Acquired Immune Deficiency Syndrome - affects the immune system. l Caused by HIV (human immunodeficiency virus). l Acquired by body fluid transfer. l The virus attacks helper T cells. Why is this bad?

54. Answer: l Body can’t produce antibodies or killer T cells and can’t fight diseases. l Symptoms: swollen glands, fever, weakness, weight loss, inability to fight common illnesses, fungi, cancers (Kaposi’s sarcoma). l No cure.

55. Immune Disorders l Allergies – overreaction to an antigen that is not normally harmful. It triggers the inflammatory response – when the body makes histamines. To reduce symptoms – take antihistamines.

56. Immune Disorders l Autoimmune Diseases – when the body fails to recognize its own cells as self and produces antibodies against its own cells. Lupus (various organs, kidneys), Multiple sclerosis (nerves), rheumatic fever (heart and joint tissue)

57. Immune Disorders l Cancer – body doesn’t recognize foreign cells as foreign and lets them multiply uncontrollably. Suppression of immune system often results in cancer.