Survey of Anatomy & Physiology Chap 14


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Survey of Anatomy & Physiology Chap 14

  1. 1. 14 The Lymphatic and Immune Systems: Your Defense Systems
  2. 2. INTRODUCTION  Immune and lymphatic systems work to protect body from pathogens that can produce disease  Without these systems, you would not survive for long
  3. 3. THE DEFENSE ZONE  If a group of pathogens try to enter body, they must first get past barriers, such as intact skin and secretions of mucous membranes
  4. 4. PHYSICAL BARRIERS  Anything that prevents invaders from getting inside your body prevents infection  Physical barriers act as first line of defense; located in areas most likely to be invaded Skin and mucous membranes of eyes, digestive, respiratory, reproductive systems
  5. 5. PHYSICAL BARRIERS  Anything that prevents invaders from getting inside your body prevents infection  Physical barriers act as first line of defense; located in areas most likely to be invaded Skin and mucous membranes of eyes, digestive, respiratory, reproductive systems
  6. 6. THE DEFENSE ZONE  If pathogen does get into body, it is recognized as not belonging  Weapons in the form of specialized cells are engaged by immune and lymphatic systems to fend off the pathogens
  7. 7. THE DEFENSE ZONE  Weapons include specialized cells and powerful chemicals of immune and lymphatic systems  Chemicals stimulate inflammatory and clean up responses  Again, this is accomplished by combined and integrated efforts of immune and lymphatic systems
  8. 8. THE LYMPHATIC SYSTEM  Both the transport system and barracks of immune system  Works closely with cardiovascular system
  10. 10. STRUCTURES OF THE LYMPHATIC SYSTEM  Smallest pipes of lymphatic system called lymph capillaries; run parallel to blood capillaries
  11. 11. STRUCTURES OF THE LYMPHATIC SYSTEM  Lymph capillaries form network between cells of connective tissues, but unlike blood capillaries, are open ended
  12. 12. THE LYMPHATIC SYSTEM  Proteins and fluids are lost from cardiovascular capillaries and enter interstitial space.
  13. 13. THE LYMPHATIC SYSTEM  Once this fluid enters lymph capillaries, it is known as lymphatic fluid (lymph)  Lymph: straw-colored, clear fluid; primary component is water
  14. 14. THE LYMPHATIC SYSTEM  Lymph capillaries empty into lymphatic vessels, similar to veins including valves; body movement and contraction of smooth muscles propels lymph through system
  16. 16. LYMPH NODES  Large vessels empty into lymph nodes, ranging in size from pinhead to an olive  Lymph nodes: filters placed all along pathways or vessels of lymphatic system
  17. 17. FIGURE 14-2 THE LYMPH NODE STRUCTURE Small, encapsulated bodies divided into sections Consist of sections of lymphatic tissue containing WBCs known as lymphocytes
  18. 18. LYMPH NODES  Lymphatic tissue surrounded by lymphatic sinuses filled with lymph fluid  Filter and destroy pathogens using WBCs
  19. 19. LYMPH NODES IN THE BODY  Concentrated in cervical, axillary, inguinal, pelvic, abdominal, thoracic, and supra trochlear areas  Adenoids and tonsils also part of lymph system
  20. 20. LYMPHATIC TRUNKS  Lymphatic vessels exiting lymph nodes empty into one of several lymphatic trunks
  21. 21. COLLECTING DUCTS  Lumbar, intestinal, and intercostal trunks empty into thoracic duct the largest lymph vessel; more than two-thirds of lymphatic system drains into this duct Lymphatic trunks empty into one of two collecting ducts
  22. 22. COLLECTING DUCTS  Bronchomediastinal, subclavian, and jugular trunks empty into right lymphatic duct; smaller duct within right thorax that empties into right subclavian vein
  23. 23. CIRCULATION OF LYMPHATIC FLUID  Lymphatic fluid flows in only one direction: from body tissues and organs to heart  Blood to tissue  Tissue to lymphatic capillaries  Lymphatic capillaries to lymphatic vessels
  24. 24. CIRCULATION OF LYMPHATIC FLUID 1. Lymphatic capillaries to lymph nodes 2. Lymph nodes to lymphatic vessels 3. Lymphatic vessels to lymphatic trunks 4. Lymphatic trunks to collecting ducts 5. Collecting ducts to subclavian veins and then back to the blood
  25. 25. LYMPH ORGANS  Spleen  Spongy saclike mass of lymphatic tissue in upper left quadrant of abdomen  Structurally similar to lymph nodes but instead of lymphatic sinuses has blood sinuses  Surrounding blood sinuses are islands of white pulp containing lymphocytes and islands of red pulp containing both RBCs and WBCs
  26. 26. LYMPH ORGANS  Spleen  Functions to remove and destroy old, damaged, or fragile RBCs  Also filters pathogens from bloodstream and destroys them like lymph node  Not vital organ; can be surgically removed; removal in children can severely compromise immunity, but has lesser effect on adults
  27. 27. LYMPH ORGANS  Thymus  Soft organ located between aortic arch and sternum  Very large in children because it must fend off new infections  Gets smaller; continues to have some activity in adults as immune system fully matures in its ability to fight infection
  28. 28. LYMPH ORGANS  Thymus  Site of mature type of WBC called a T lymphocyte (made in the bone marrow)
  30. 30. LYMPHATIC AND IMMUNE Stores and Transports Barriers Nodes Organs Cells Chemicals Vessels
  31. 31. THE IMMUNE SYSTEM  Comprised of cells, chemicals, and barriers that protect body from invasion by pathogens  Some processes active, some passive, some inborn, and others change with experience
  32. 32. ANTIGENS-SELF OR FOREIGN?  Molecules on outer surface of cell membrane that identify them as friend or foe  Each living thing has unique cell surface antigens, allowing immune system to distinguish between cells that are naturally yours and cells that are not
  33. 33. ANTIGENS  Ability called self- recognition and non-selfrecognition; is heart of how immune system functions  Well-functioning immune system ignores self antigens and attacks non-self antigens
  34. 34. ANTIBODIES  Proteins the body makes that bind to antigens, eventually destroying them  One of most potent weapons of immune system  Called into action when foreign antigen invades the body
  35. 35. INNATE VERSUS ADAPTIVE IMMUNITY  Innate (natural) immunity  First line of defense against invasion  Body's inborn ability to fight infection  Not affected by environment  Permanent
  36. 36. INNATE VERSUS ADAPTIVE IMMUNITY  Innate (natural) immunity  Prevents invasion, or if pathogens do get inside, takes steps to stop spread of infection
  37. 37. INNATE IMMUNITY-RECOGNIZES A FOREIGN INVADER The body’s first line of defense recognizes that invader is present but can’t identify it specifically Like setting off a metal detector but not knowing exactly what the item is that did it
  38. 38. INNATE VERSUS ADAPTIVE IMMUNITY  Innate (natural) immunity  Cannot improve with experience  Because it does not recognize specific pathogens, it cannot "remember" an infection that body has encountered before “ I CAN’T REMEMBER”
  39. 39. INNATE VERSUS ADAPTIVE IMMUNITY  Crude mechanism for defending body  Indiscriminately killing pathogens and healthy tissue alike Take that, invader I’m one of you!!
  40. 40. INNATE VERSUS ADAPTIVE IMMUNITY  Adaptive (acquired) immunity  Backs up innate immunity, specifically targeting invaders and sparing healthy tissue as much as possible  Remembers invaders from previous encounters and prepares for future invasion, improving response with experience by learning and changing
  41. 41. INNATE VERSUS ADAPTIVE IMMUNITY  Innate and adaptive immunity work together  Innate immunity prepares way for adaptive immunity, weakening pathogens and stimulating components of adaptive immunity
  42. 42. INNATE VERSUS ADAPTIVE IMMUNITY  Adaptive immunity, in turn, stimulates innate immunity attacking pathogen on two fronts
  43. 43. INNATE VERSUS ADAPTIVE IMMUNITY-HUMORAL* & CELLULAR *Humoral means found in body fluids
  44. 44. CELLS OF THE BODY  White blood cells (WBC or leukocytes) are cells responsible for defending body against invaders  Red blood cells responsible for carrying oxygen throughout body  Platelets responsible for blood's ability to clot
  45. 45. CELLS OF THE BODY  Leukocytes  Form in bone marrow; move to other parts of body to grow and mature  Not released into bloodstream unless infection present  Various types of white blood cells required to protect body in varying circumstances
  46. 46. LYMPHOCYTES  T (for Thymus) and B (for bone marrow) cells  Form in bone marrow; some move to other parts of body to grow and mature  T cells go to the thymus to mature  B cells stay, develop and mature in the bone marrow
  47. 47. LYMPHOCYTES-T AND B CELLS  Specific T cells called T helper cells stimulate “killer T cells” which directly bind to antigen or pathogen and destroy it  T helper cells also stimulate B cells to make B plasma cells which produce antibodies and make B memory cells
  48. 48. LYMPHOCYTES-T AND B CELLS  Both formed in the marrow both cells stimulated by the presence of a foreign antigen  B cells develop into plasma cells which forms antibodies to specific antigen and memory cells which “remember” it later
  50. 50. CHEMICALS TO PROTECT BODY FROM INVADERS  Found in body; assist in destroying and neutralizing invaders  Cytokines:  Involved in both innate and adaptive immunity
  51. 51. CYTOKINES  Cytokines are proteins produced by damaged tissues and WBCs that stimulate immune response in variety of ways:  Increasing inflammation  Stimulating lymphocytes  Enhancing phagocytosis
  52. 52. INTERFERONS  Cytokine produced by cells that have been infected by virus  Binds to neighboring, uninfected cells and stimulates them to produce chemicals that may protect these cells from viruses
  53. 53. INFLAMMATION  Also called inflammatory response  Typical symptoms: pain, swelling, heat, and redness
  54. 54. INFLAMMATION  Deliberate action of body in response to tissue damage, whether mechanical or pathological injury  Response helps to wall off infected area to prevent further spread and allow battle to focus at site
  55. 55. INFLAMMATION  When tissue is damaged, cells send out chemicals such as histamine, an inflammation modulator
  56. 56. INFLAMMATION  These chemicals attract WBCs to site, increase permeability of capillaries, and cause local vasodilitation; extra fluid causes swelling  More blood comes to site, causing heat
  57. 57. INFLAMMATION  WBCs destroy pathogens and clean away dead cells  Increase in fluid and cells coming to area increases pressure and creates pain  Innate immune mechanism, but plays important part in adaptive immunity
  59. 59. FEVER  During infection, immune system releases cytokines that promote inflammation and immune responses  One of cytokine targets in brain is HYPOTHALAMUS responsible for setting and maintaining body temperature
  60. 60. FEVER  Effect of cytokine is elevated temperature set point, or fever  Rise in body temperature is deliberate attempt by immune system to destroy pathogens
  61. 61. INNATE IMMUNITY-BARRIERS  First, pathogens must get past physical and chemical barriers; most pathogens kept out by these barriers Tears, saliva, urine, mucous secretions and sweat contain chemical barriers
  63. 63. INNATE IMMUNITY  Release of cytokines and stimulation of inflammation attract macrophages to infection site
  64. 64. INNATE IMMUNITY  Macrophages phagocytize infected cells  Release chemicals to further stimulate inflammation, activate more immune cells
  65. 65. INNATE IMMUNITY Pathogens are under attack from: Phagocytosis Noxious chemicals Membrane rupture Clumping Alteration to molecular structure
  66. 66. INNATE IMMUNITY  Chemicals have specifically signaled hypothalamus to raise body temperature and you run a fever
  67. 67. INNATE IMMUNITY  Remember: This is crude warfare, with innate immunity destroying anything non-self  Desperate attempt to defeat invaders, sometimes killing uninfected cells… All leading to activation of adaptive immunity
  68. 68. INNATE IMMUNITY  When phagocytic cells ingest pathogens, they display foreign antigen on cell membrane, essential for activation of B and T cells
  69. 69. ADAPTIVE IMMUNITY  Fights specific pathogens; has memory, "learns" from experience, recognizes specific pathogens
  71. 71. ADAPTIVE IMMUNITY Because of adaptive immunity, immunizations are able to prevent illness
  72. 72. ADAPTIVE IMMUNITY Innate and adaptive immunity work hand in hand; one cannot do its job without the other
  73. 73. ADAPTIVE IMMUNITY IS THEN ACQUIRED Exposure is either Exposure is either Acquired Acquired immunity immunity occurs as the occurs as the body body “adapts” to “adapts” to the the environment environment to which it is to which it is exposed exposed “passive” “passive” (nonspecific (nonspecific antigen exposure) antigen exposure) or “active” or “active” (specific targeted (specific targeted exposure) exposure) Exposure is Exposure is “natural” or “natural” or “artificial” “artificial” (created by (created by humans) humans)
  74. 74. ACQUIRED ACTIVE IMMUNITY Daily Life Acquired during vaccinations
  79. 79. THE BIG PICTURE  Army of pathogens wants to invade body; first must get past body's barriers  If invader gets inside body, series of weapons stimulated by nonself-antigen  Cells (neutrophils, macrophages, and basophils) stimulated  Chemicals (cytokines) released that stimulate inflammation and phagocytosis
  80. 80. THE BIG PICTURE  Macrophages and other cells which have ingested some of invaders move to lymphatic system and search lymph nodes, looking for T and B cells that will recognize intruder
  81. 81. THE BIG PICTURE  Helper T cells activate and cause proliferation of B cells and cytotoxic T cells, as well as releasing chemicals to further stimulate phagocytosis and inflammation T cells (green) infected with HIV (red)
  82. 82. THE BIG PICTURE  Cytotoxic T cells activated and proliferate  B cells produce antibodies that destroy invaders and further stimulate immune response  Cytotoxic T cells destroy invaders directly and release chemicals that further stimulate immune response
  83. 83. THE BIG PICTURE  Immune response, both innate and adaptive, will continue to be stimulated until feedback loop stopped, at least in part by regulatory T cells  Memory B cells and T cells stored in lymph nodes for later use if another army of same types of pathogens invade
  84. 84. THE BIG PICTURE  Macrophages and other phagocytic cells will clean up debris left by “warfare” waged by immune system and body will return to normal
  86. 86. AUTO IMMUNE DISEASE Read article “Auto Immune Diseases” Read article “Auto Immune Diseases” It is believed that viruses can incorporate genetic material into human cells that changes it’s “ID CARD”, so that it is then identified as foreign, triggering an antigen-antibody reaction
  88. 88. CHAP 14 TAKE HOME EXAM Complete Worksheet No. 1 Complete Worksheet No. 1 and the Labeling Activity 1 and 3 and the Labeling Activity 1 and 3 for credit (46 points) .. for credit (46 points) Questions #24 and #25 are Questions #24 and #25 are EXTRA CREDIT EXTRA CREDIT (worth 7 points) (worth 7 points) One ESSAY Question on the One ESSAY Question on the Lymphatic System will appear on Lymphatic System will appear on your FINAL EXAM your FINAL EXAM