Topic 10: Lymphatic System

• What does the lymphatic system consist of?

  Lymph, lymphatic vessels, and lymphatic organs

  
• What is lymphatic tissue?

  A specialized form of reticular connective tissue
• What are the primary components of the lymphatic system?

  Spleen, thymus, lymph nodes, lymph nodules

  
• Where do lymphatic vessels begin?

  As lymphatic capillaries in tissue spaces
• How do lymphatic capillaries relate to larger lymphatic vessels?

  Lymphatic capillaries merge to form larger vessels

  
• Where does the thoracic duct empty its lymph?

  Into the left internal jugular and subclavian veins
• What is the function of the right lymphatic duct?

  It empties lymph into the right internal jugular vein

  
• What is interstitial fluid called after it enters lymphatic vessels?

  Lymph
• What are the three primary functions of the lymphatic system?

  Drains excess fluid, transports lipids, immune responses
• What are lymph nodes composed of?

  Masses of B cells and T cells
• What maintains the flow of lymph?

  The respiratory and skeletal muscle pumps
• How does the respiratory pump affect lymph flow?

  Increases flow during inspiration due to pressure changes
• What is the role of skeletal muscle pump in lymph flow?

  It forces valves open to increase lymph flow
• What are primary lymphatic organs?

  Sites where stem cells develop into B and T cells
• Where do T cells mature?

  In the thymus
• What is the function of the thymus?

  Maturation and education of T lymphocytes
• What are secondary lymphatic organs?

  Sites where most immune responses occur
• Where are lymph nodes heavily concentrated?

  Near mammary glands, axillae, and groin
• What are lymphatic nodules?

  Egg-shaped masses of lymphatic tissue
• What is the largest single mass of lymphatic tissue?

  The spleen
• What types of tissue does the spleen contain?

  White pulp and red pulp

  
• What is the function of the tonsils?

  Immune responses against foreign substances
• What does innate immunity include?

  External barriers and internal defenses

  
• What are the first line of defense components in innate immunity?

  Skin and mucous membranes
• What is the role of phagocytes in innate immunity?

  Ingest foreign particulate matter
• What are the four main types of antimicrobial substances?

  Interferons, complement system, iron-binding proteins
• What is inflammation?

  A nonspecific defensive response to tissue damage
• What are symptoms of inflammation?

  Pain, redness, and heat
• What does fever do in the body?

  Intensifies effects of interferons and speeds repair
• What is the function of sebum in innate immunity?

  Forms protective acidic film over skin
• What do interferons do?

  Protect uninfected host cells from viruses
• What is adaptive immunity?

  Production of specific cells or antibodies
• What are antigens?

  Substances recognized as foreign by the immune system
• How do B cells and T cells develop?

  From stem cells in primary lymphatic organs
• What are the two types of adaptive immunity?

  Cell-mediated and antibody-mediated immunity

  
• What do cytotoxic T cells do?

  Directly attack invading antigens
• What do B cells transform into?

  Plasma cells that produce antibodies
• What types of molecules are antigens typically?

  Large complex molecules like proteins
• Which lymphocytes are involved in adaptive immunity?

  B cells and T cells
• Where do B cells and T cells develop?

  In primary lymphatic organs