Chapter 28 Review

  1. A person acquires naturally acquired active immunity by being naturally exposed to an antigen and subsequently making antibodies and memory cells against the antigen.
  2. Neutrophils and monocytes are the most active phagocytes in the blood.
  3. When an area of the body becomes injured or infected with a pathogen, inflammation results.
  4. Mucous membranes and skin provide mechanical barriers against pathogens.
  5. Although both B cells and T cells circulate in the blood, most of the lymphocytes in blood are T cells.
  6. B cells respond to an antigen by becoming plasma cells and making antibodies against a specific antigen.
  7. Macrophages and lymphocytes are the major WBCs involved in specific defenses.
  8. T cells bind to antigens on cells and attack them directly, providing a cell-mediated response.
  9. Some activated T cells become memory T cells that "remember" the pathogen that activated the original T cell. When a person is later exposed to the same pathogen, memory cells trigger an immune response that is more effective than the first response.
  10. Monokines assist in regulation of the immune response by increasing B cell production and stimulating red bone marrow to produce more WBCs.
  11. T cells secrete cytokines called lymphokines, which increase T-cell production and directly kill cells that have antigens.
  12. Natural killer cells primarily target cancer cells, but they also protect the body against many types of pathogens.
  13. A major histocompatibility complex is a large protein complex that is unique to each individual and is present on every cell in the body.
  14. Natural killer cells secrete chemicals that produce holes in the membranes of harmful cells. Unlike B cells and T cells, NK cells do not have to recognize a specific antigen to start destroying pathogens.
  15. Cytotoxic T cells are important in protecting the body against viruses and cancer cells.
  16. Memory T cells "remember" the pathogen that activated the original T cell. When a person is later exposed to the same pathogen, memory cells trigger an immune response.
  17. Helper T cells increase antibody formation, memory cell formation, B cell formation, and phagocytosis.
  18. IgM is a large antibody that primarily binds to antigens on food, bacteria, or incompatible blood cells.
  19. IgG is an antibody that primarily recognizes bacteria, viruses, and toxins.
  20. IgA is an antibody found in various secretions of the body, including breast milk, sweat, tears, saliva, and mucus. It prevents pathogens from entering the body.
  21. IgE is an antibody found wherever IgA is located; it is involved in triggering allergic reactions.
  22. IgD is an antibody found on the cell membranes of B cells; it is thought to control the activity of B cells.
  23. A person receives naturally acquired passive immunity from his mother through breast milk.
  24. A person acquires naturally acquired active immunity by being naturally exposed to an antigen and subsequently making antibodies and memory cells against the antigen.
  25. A person develops artificially acquired active immunity by being injected with a pathogen and subsequently making antibodies and memory cells against the pathogen.
  26. Species resistance means that a species typically gets only diseases unique to that species; this is considered a type of nonspecific defense.
  27. Having an infectious disease caused by a pathogen leads to the development of naturally acquired active immunity.
  28. Immunizations and vaccines cause artificially acquired active immunity.
  29. Over-the-counter antihistamines and decongestants can reduce allergy symptoms.
  30. An allergy is an excessive immune response that involves IgE antibodies and mast cells.
  31. Anaphylaxis is a life-threatening condition in which blood vessels dilate so quickly that blood pressure drops too fast for organs to adjust.
  32. An injection of epinephrine is used to rescue a person experiencing anaphylaxis. The epinephrine causes vasoconstriction, which increases blood pressure.
  33. Staging is a process that determines how large a tumor is and how far cancer cells have spread throughout the body.
  34. A carcinogen is any factor that is known to cause the formation of cancer.
  35. The squeezing action of neighboring skeletal muscles pushes lymph through the lymphatic vessels.
  36. If lymph cannot be pushed through the vessels, it leaks back out of the lymphatic capillaries, causing edema.
  37. The spleen filters the blood and removes worn-out red blood cells from the bloodstream.
  38. The thymus is large in infants because it assists with the production of lymphocytes for the child's immature immune system. As a person ages, the thymus shrinks.
  39. Chemicals in body fluids provide chemical barriers that destroy pathogens. For example, acids in the stomach destroy pathogens that are swallowed.
  40. Interferon is a chemical that blocks viruses from infecting cells.
  41. Fever removes iron needed by pathogens from the bloodstream and activates phagocytic cells in the body to attack pathogens.
  42. In inflammation, blood vessels in the injured area dilate and become leaky, allowing more blood to enter the area. This brings phagocytic cells to the area to attack the pathogen and provides proteins and clotting factors to stop bleeding.
  43. Memory cells develop as part of the primary immune response and later carry out the secondary immune response.
  44. A primary immune response takes several weeks to make memory cells that are later active in the secondary response.
  45. SLE does not cause tender lymph nodes in the neck.
  46. Signs and symptoms of chronic fatigue syndrome include extreme fatigue, mild fever, sore throat, tender lymph nodes in the neck or armpit, general body aches, joint pain, sleep disturbances, and depression.
  47. The spleen, not the thymus, removes aged RBCs from blood circulation.
  48. The thymus, not the spleen, decreases in size as a person ages.
  49. Symptoms of AIDS include a T-cell count below 200, fever, diaphoresis, weakness, weight loss, frequent infections, meningitis, and encephalitis.
  50. Although you cannot be sure Sherry has mononucleosis, it is a good possibility. Because Sherry has a frequent cough, you should wear a mask while you are in the exam room with her. Mononucleosis can be spread by coughing.
  51. Symptoms of AIDS include a T-cell count below 200, fever, diaphoresis, weakness, weight loss, frequent infections, meningitis, and encephalitis.
  52. Although you cannot be sure Sherry has mononucleosis, it is a good possibility. Because Sherry has a frequent cough, you should wear a mask while you are in the exam room with her. Mononucleosis can be spread by coughing.