Chapt16 lymphatic and immunity

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Chapt16 lymphatic and immunity

  1. 1. Brenda Holmes MSN/Ed, RN Associate Professor Biology South Arkansas Community College Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display
  2. 2. <ul><li>The lymphatic system is a vast collection of cells and biochemicals that travel in lymphatic vessels </li></ul><ul><li>It is a network of vessels that assist in circulating fluids </li></ul><ul><li>It is closely associated with the cardiovascular system </li></ul><ul><li>It transports excess fluid away from the interstitial spaces </li></ul><ul><li>It transports fluid to the bloodstream </li></ul><ul><li>It transports fats to the bloodstream </li></ul><ul><li>It helps defend the body against diseases </li></ul>
  3. 3. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lymphatic capillaries Pulmonary capillary network Lymph node Lymphatic vessels Blood flow Lymph node Lymph flow Systemic capillary network Lymphatic capillaries
  4. 4. Tissue cells Arteriole Venule Lymphatic capillary Capillary bed Lymphatic vessel Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  5. 5. <ul><li>The walls are similar but thinner than those of veins </li></ul><ul><li>Lymphatic vessels are composed of three layers: </li></ul><ul><ul><li>An endothelial lining (inner) </li></ul></ul><ul><ul><li>Smooth muscle (middle) </li></ul></ul><ul><ul><li>Connective tissue (outer) </li></ul></ul><ul><li>Larger vessels lead to lymph nodes and then to larger lymphatic trunks </li></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © The McGraw-Hill Companies, Inc./Dennis Strete, photographer
  6. 6. <ul><li>The trunks drain lymph from the lymphatic vessels </li></ul><ul><li>They are named for the regions they serve such as lumbar, intestinal, intercostal, bronchomediastinal, subclavian, and jugular </li></ul>Jugular trunk Right lymphatic duct Brachiocephalic vein Bronchomediastinal trunk Intercostal trunk Internal jugular vein Thoracic duct Subclavian trunk Thoracic duct Intestinal trunk Lumbar trunk Lymphatic vessels Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  7. 7. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lymph nodes Thoracic duct Thoracic duct Right lymphatic duct Right internal jugular vein (a) (b) Area drained by right lymphatic duct Right lymphatic duct Lymphatic trunks Lymphatic vessels Left internal jugular vein Left subclavian vein Cisterna chyli Right subclavian vein Axillary lymph nodes Lymphatics of mammary gland
  8. 8. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Afferent lymphatic vessel Collecting duct Subclavian vein Efferent lymphatic vessel Lymphatic capillary Lymph node Lymphatic trunk
  9. 9. <ul><li>Lymph is essentially tissue fluid that has entered a lymphatic capillary </li></ul><ul><li>Lymph formation depends on tissue fluid formation </li></ul>
  10. 10. <ul><li>Capillary blood pressure filters water and small molecules from the plasma </li></ul><ul><li>The resulting fluid has: </li></ul><ul><ul><li>Much the same consistency as plasma </li></ul></ul><ul><ul><li>Contains water and dissolved substances </li></ul></ul><ul><ul><li>Contains smaller proteins which create plasma colloid osmotic pressure </li></ul></ul>
  11. 11. <ul><li>Filtration from the plasma normally exceeds reabsorption, leading to the net formation of tissue fluid </li></ul><ul><li>This increases the tissue fluid hydrostatic pressure within interstitial spaces forcing fluid into lymphatic capillaries forming lymph </li></ul><ul><li>This process prevents accumulation of excess tissue fluid or edema </li></ul>
  12. 12. <ul><li>Lymphatic vessels play a role in: </li></ul><ul><ul><li>Absorption of dietary fats </li></ul></ul><ul><ul><li>Delivering fats to the bloodstream </li></ul></ul><ul><ul><li>Collecting of excess interstitial fluids </li></ul></ul><ul><ul><li>Delivering excess fluids to the bloodstream </li></ul></ul><ul><ul><li>Delivering foreign particles to the lymph nodes </li></ul></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Flow of lymph Epithelial cell Filaments anchored to connective tissue Movement of tissue fluid
  13. 13. <ul><li>Hydrostatic pressure of tissue fluid drives the lymph into the lymphatic capillaries </li></ul><ul><li>Muscle activity largely influences the movement of lymph through the lymphatic vessels via: </li></ul><ul><ul><li>Action of skeletal muscles </li></ul></ul><ul><ul><li>Respiratory movements </li></ul></ul><ul><ul><li>Smooth muscle in the larger lymphatic vessels </li></ul></ul><ul><ul><li>Valves in the lymphatic vessels </li></ul></ul>
  14. 14. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sinus Capsule (a) Nodule Hilum Artery Medulla (macrophages, T cells) Capsule Subcapsule (macrophages, B cells) Efferent lymphatic vessel Lymph flow Germinal center (B cells) Vein Lymph flow Afferent lymphatic vessel Germinal center b: © The McGraw-Hill Companies, Inc./Al Telser, photographer (b)
  15. 15. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood vessels Lymph node Muscle Lymphatic vessels © Dr. Kent M. Van De Graaff
  16. 16. <ul><li>Lymph nodes or lymph glands are located along the lymphatic pathways </li></ul><ul><li>They contain lymphocytes and macrophages to fight invading pathogens </li></ul>
  17. 17. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lymph flow Sinus Capsule (a) Nodule Hilum Lymph flow Artery Vein Afferent lymphatic vessel Germinal center (B cells) Subcapsule (macrophages, B cells) Medulla (macrophages, T cells) Efferent lymphatic vessel
  18. 18. <ul><li>Lymph nodes are found in groups or chains along the paths of the larger lymphatic vessels throughout the body, including the: </li></ul><ul><ul><li>Cervical region </li></ul></ul><ul><ul><li>Axillary region </li></ul></ul><ul><ul><li>Supratrochlear region </li></ul></ul><ul><ul><li>Inguinal region </li></ul></ul><ul><ul><li>Pelvic cavity </li></ul></ul><ul><ul><li>Abdominal cavity </li></ul></ul><ul><ul><li>Thoracic cavity </li></ul></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Thoracic lymph node Axillary lymph node Cervical lymph node Supratrochlear lymph node Abdominal lymph node Pelvic lymph node Inguinal lymph node
  19. 19. <ul><li>Lymph nodes have two primary functions: </li></ul><ul><ul><li>Filter potentially harmful particles from the lymph </li></ul></ul><ul><ul><li>Act with immune surveillance provided by macrophages and lymphocytes </li></ul></ul><ul><li>Along with the red bone marrow, the lymph nodes are centers for lymphocyte production </li></ul>
  20. 20. <ul><li>These are two other lymphatic organs with functions similar to those of the lymph nodes </li></ul>
  21. 21. Thymus in fetus Thymus in adult <ul><li>The thymus is: </li></ul><ul><ul><li>Larger in infancy and during puberty </li></ul></ul><ul><ul><li>Small in an adult </li></ul></ul><ul><ul><li>Replaced by fat and connective tissue in the elderly </li></ul></ul><ul><ul><li>Site of T lymphocyte (or T cell) production </li></ul></ul><ul><ul><li>Secretes protein hormones called thymosins </li></ul></ul>Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  22. 22. Larynx Thymus Lung Liver (a) (b) Diaphragm Thyroid gland Heart Stomach Spleen Lobule Trachea Connective tissue b: © The McGraw-Hill Companies, Inc./Dennis Strete, photographer Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  23. 23. <ul><li>The spleen is: </li></ul><ul><ul><li>The largest lymphatic organ </li></ul></ul><ul><ul><li>Located in the upper left abdominal quadrant </li></ul></ul><ul><ul><li>Has sinuses filled with blood </li></ul></ul><ul><ul><li>Contains two tissue types: </li></ul></ul><ul><ul><ul><li>White pulp ( lymphocytes) </li></ul></ul></ul><ul><ul><ul><li>Red pulp ( red blood cells, lymphocytes and macrophages) </li></ul></ul></ul>Spleen Artery of pulp White pulp Red pulp (a) (b) Capillary Capsule Capsule White pulp Red pulp Splenic artery Splenic vein Connective tissue Venous sinus b: © The McGraw-Hill Companies, Inc./Al Telser, photographer Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  24. 24.
  25. 25. <ul><li>The presence and multiplication of a pathogen in the body may cause an infection </li></ul><ul><li>Pathogens are: </li></ul><ul><ul><li>Disease causing agents </li></ul></ul><ul><ul><li>Bacteria, viruses, complex microorganisms, and spores of multicellular organisms </li></ul></ul><ul><li>The body can prevent entry of pathogens or destroy them with defense mechanisms such as: </li></ul><ul><ul><li>Innate defenses : </li></ul></ul><ul><ul><ul><li>These are general defenses </li></ul></ul></ul><ul><ul><ul><li>They protect against many pathogens </li></ul></ul></ul><ul><ul><li>Adaptive defenses : </li></ul></ul><ul><ul><ul><li>Known as immunity </li></ul></ul></ul><ul><ul><ul><li>More specific and precise targeting specific antigens </li></ul></ul></ul><ul><ul><ul><li>Are carried out by lymphocytes </li></ul></ul></ul>
  26. 26.
  27. 27. <ul><li>Refers to a given type of organism, or species, that develops diseases unique to it </li></ul>
  28. 28. <ul><li>The skin and mucous membranes create mechanical barriers </li></ul><ul><li>Mechanical barriers are considered the first line of defense (all other non-specific defenses are part of the second line of defense) </li></ul>
  29. 29. <ul><li>Enzymes in body fluids provide a chemical barrier to pathogens, and they may include: </li></ul><ul><ul><li>Interferons are horomone-like peptides and stimulate phagocytosis </li></ul></ul><ul><ul><li>Defensins are peptides produced by neutrophils and other granulocytes. They cripple microbes. </li></ul></ul><ul><ul><li>Collectins are proteins with broad protection against bacteria, yeast and some viruses </li></ul></ul><ul><ul><li>Complement is a group of proteins in plasma and other body fluids that stimulate inflammation, attract phagocytes and enhance phagocytosis </li></ul></ul>
  30. 30. <ul><li>NK cells are a small population of lymphocytes defending against viruses and cancer by secreting cytolytic substances called perforins that destroy the infected cell </li></ul><ul><li>NK may also enhance inflammation </li></ul>
  31. 31. <ul><li>Inflammation produces local redness, swelling, heat and pain </li></ul><ul><li>Table 16.2 summarizes the process </li></ul>
  32. 32. <ul><li>Phagocytosis removes foreign particles from the lymph </li></ul><ul><li>Phagocytes are also in the blood vessels and in the tissues of the spleen, liver or bone marrow </li></ul><ul><li>The most active phagocytic cells are neutrophils and monocytes </li></ul><ul><li>Chemicals attract these phagocytic cells to the injury and this is called chemotaxis </li></ul>
  33. 33. <ul><li>A fever begins when a viral or bacterial infection stimulates lymphocytes to proliferate, producing cells that secrete a substance called interleukin-1 (IL-1) </li></ul>
  34. 34. <ul><li>This is the third line of defense and known as immunity </li></ul><ul><li>It is resistance to particular pathogens or to their toxins or metabolic by-products </li></ul><ul><li>It is based on the ability to distinguish molecules that are part of the body (“self” from “non-self”) </li></ul><ul><li>Antigens are molecules that can elicit an immune response </li></ul>
  35. 35. <ul><li>Antigens may be: </li></ul><ul><ul><li>Proteins </li></ul></ul><ul><ul><li>Polysaccharides </li></ul></ul><ul><ul><li>Glycoproteins </li></ul></ul><ul><ul><li>Glycolipids </li></ul></ul><ul><li>The most effective antigens are large and complex </li></ul><ul><li>Haptens are small molecules that are not antigenic by themselves, but when they combine with a large molecule can stimulate an immune response </li></ul>
  36. 36. B cell Thymus T cell T cell 1 2 3 4 B cell Stem cells in red bone marrow give rise to lymphocyte precursors. Red bone marrow Some lymphocyte precursors are processed within the bone marrow to become B cells . Both T cells and B cells are transported through the blood to lymphatic organs, such as the lymph nodes, lymphatic ducts, and spleen . Some lymphocyte precursors are processed in the thymus to become T cells. Blood transport Blood transport Lymphocyte precursors Blood transport Lymph node Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  37. 37. <ul><li>A lymphocyte must be activated before it can respond to an antigen </li></ul><ul><li>T cell activation requires antigen-presenting cell (accessory cell) and may include macrophages, B cells and several other types of cells </li></ul><ul><li>Requires major histocompatibility complex (MHC) or human leukocyte antigens (HLA) to recognize “non-self” </li></ul><ul><li>T cells can synthesize and secrete polypeptides called cytokines </li></ul><ul><li>Types of specialized T cells include: </li></ul><ul><ul><li>Helper T cells </li></ul></ul><ul><ul><li>Cytotoxic T cells </li></ul></ul><ul><ul><li>Memory T cells </li></ul></ul>
  38. 38.
  39. 39. <ul><li>B cells can be activated when an antigen fits the shape of its receptor </li></ul><ul><li>Most of the time B cell activation requires T cells </li></ul><ul><li>T cells release cytokines that stimulate B cells </li></ul><ul><li>Some B cells may become memory B cells while others differentiate into plasma cells and produce and secrete large globular proteins called antibodies or immunoglobulins </li></ul>
  40. 40. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cytokines Antigen B cells Activated B cell Interleukin-2 1 3 2 4 5 (a) Macrophage Helper T cell (b) Cytotoxic T cell Cytotoxic T cell contacts Displayed antigen Helper T cell contacts displayed antigen and proliferates Cytotoxic T cell Helper T cells Activated helper T cell interacts with cytotoxic T cell (which has combined with an identical antigen) and releases interleukin-2, which activates the cytotoxic T cell Prolifera tion and Differentiation Memory T cell Cytotoxic T cell Antigen receptor B cell combines with antigen Macrophage displays ingested antigen on its surface Displayed antigen b: © Manfred Kage/Peter Arnold
  41. 41. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Activated B cell Proliferation B cells Antigen Cytokines Activation 1 2 3 Antigen receptor Stimulation by activated helper T cell Clone of B cells
  42. 42. Antigen Proliferation Antigen Receptor (antibody) Receptor-antigen combination Activated B cell Cytokines from helper T cell Clone of B cells Proliferation and Differentiation Proliferation and Differentiation Endoplasmic reticulum Released antibodies Plasma cell (antibody-secreting cell) Memory cell (dormant cell) Plasma cell (antibody-secreting cell) Memory cell (dormant cell) Clone of B cells Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  43. 43.
  44. 44.
  45. 45. Immunotherapy
  46. 46. Plasma antibody concentration 10 0 20 30 Primary response Secondary response 40 Days after exposure to antigen Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  47. 47.
  48. 48. <ul><li>Type I </li></ul><ul><ul><li>Immediate-reaction allergy </li></ul></ul><ul><ul><li>Occurs minutes after contact with allergen </li></ul></ul><ul><ul><li>Symptoms include hives, hay fever, asthma, eczema, gastric disturbances, and anaphylactic shock </li></ul></ul><ul><li>Type II </li></ul><ul><ul><li>Antibody-dependent cytotoxic reaction </li></ul></ul><ul><ul><li>Takes 1-3 hours to develop </li></ul></ul><ul><ul><li>Transfusion reaction </li></ul></ul><ul><li>Type III </li></ul><ul><ul><li>Immune-complex reaction </li></ul></ul><ul><ul><li>Takes 1-3 hours to develop </li></ul></ul><ul><ul><li>Antibody complexes cannot be cleared from the body </li></ul></ul><ul><ul><li>Damage of body tissues </li></ul></ul><ul><li>Type IV </li></ul><ul><ul><li>Delayed-reaction allergy </li></ul></ul><ul><ul><li>Results from repeated exposure to allergen </li></ul></ul><ul><ul><li>Eruptions and inflammation of the skin </li></ul></ul><ul><ul><li>Takes about 48 hours to occur </li></ul></ul>
  49. 49. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. B cell Plasma cell Mast cell IgE receptor Granule (a) 1 2 3 5 4 Allergen Allergen Allergic reaction Histamine and other chemicals Mast cell releases allergy mediators Subsequent contact with allergen Antibodies attach to mast cell Released IgE antibodies Initial B cell contact with allergen Plasma cell secretes antibodies
  50. 50. <ul><li>Successfully transplanted tissues and organs: </li></ul><ul><ul><li>Cornea </li></ul></ul><ul><ul><li>Kidney </li></ul></ul><ul><ul><li>Liver </li></ul></ul><ul><ul><li>Pancreas </li></ul></ul><ul><ul><li>When the donor’s tissues are recognized as foreign there is a tissue rejection reaction </li></ul></ul><ul><ul><li>Resembles the cellular immune response against antigens </li></ul></ul><ul><ul><li>Important to match MHC antigens </li></ul></ul><ul><ul><li>Immunosuppressive drugs used to prevent rejection </li></ul></ul><ul><ul><li>Heart </li></ul></ul><ul><ul><li>Bone marrow </li></ul></ul><ul><ul><li>Skin </li></ul></ul>
  51. 51.
  52. 52. <ul><li>The immune system fails to distinguish “self” from “non-self” and the body produces antibodies called autoantibodies, and cytotoxic T cells to attack the body’s tissues and organs </li></ul>
  53. 53. <ul><li>The immune system declines early in life as the thymus gland shrinks (only 25% as powerful as it once was) </li></ul><ul><li>There is a higher risk of infection </li></ul><ul><li>Antibody response to antigens becomes slower </li></ul><ul><li>IgA and IgG antibodies increase </li></ul><ul><li>IgM and IgE antibodies decrease </li></ul><ul><li>Elderly may not be candidates for certain medical treatments that suppresses immunity </li></ul>
  54. 54. Immunity Breakdown: AIDS
  55. 55. Important Points in Chapter 16: Outcomes to be Assessed <ul><li>16.1: Introduction </li></ul><ul><li>Describe the general functions of the lymphatic system. </li></ul><ul><li>16.2: Lymphatic Pathways </li></ul><ul><li>Identify and describe the parts of the major lymphatic pathways. </li></ul><ul><li>16.3: Tissue Fluid and Lymph </li></ul><ul><li>Describe how tissue fluid and lymph form, and explain the function of lymph. </li></ul><ul><li>16.4: Lymph Movement </li></ul><ul><li>Explain how lymphatic circulation is maintained, and describe the consequence of lymphatic obstruction. </li></ul>
  56. 56. Important Points in Chapter 16: Outcomes to be Assessed <ul><li>16.5: Lymph Nodes </li></ul><ul><li>Describe a lymph node and its major functions. </li></ul><ul><li>Describe the location of the major chains of lymph nodes. </li></ul><ul><li>16.6: Thymus and Spleen </li></ul><ul><li>Discuss the locations and functions of the thymus and spleen. </li></ul><ul><li>16.7: Body Defenses Against Infection </li></ul><ul><li>Distinguish between innate (nonspecific) and adaptive (specific) defenses. </li></ul><ul><li>16.8: Innate (Nonspecific) Defenses </li></ul><ul><li>List seven innate body defense mechanisms, and describe the action of each mechanism. </li></ul>
  57. 57. Important Points in Chapter 16: Outcomes to be Assessed <ul><li>16.9: Adaptive (Specific) Defenses, or Immunity </li></ul><ul><li>Explain how two major types of lymphocytes are formed, activated, and how they function in immune mechanisms. </li></ul><ul><li>Discuss the origins and actions of the five different types of antibodies. </li></ul><ul><li>Distinguish between primary and secondary immune responses. </li></ul><ul><li>Distinguish between active and passive immunity. </li></ul><ul><li>Explain how allergic reactions, tissue rejection reactions, and autoimmunity arise from immune mechanisms. </li></ul><ul><li>16.10: Lifespan Changes </li></ul><ul><li>Describe lifespan changes in immunity. </li></ul>

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