Lymphatic System

  1. What are the 2 "parts" of the lymphatic system?
    • Lymphatic Vessels
    • Lymphatic Tissues and Organs
  2. What does the lymphatic system do?
    • Transport fluids back to the blood
    • Body defense and resistance to disease
  3. What is lymph?
    Excess fluid carried by lymphatic vessels
  4. What are the properties of lymphatic vessels?
    • One way system towards the heart
    • No pump
    • Moves fluid by milking action of the skeletal muscles and rhythmic contraction of smooth muscle in vessel walls
  5. How do lymph capillaries work?
    • Walls overlap to make flap like mini valves
    • High pressure on the inside closes valves
    • Fluid leak into lymph capillaries
  6. What are lymph collecting vessels?
    • Vessels that collect lymph from capillaries
    • Carry lymph away from lymph nodes
    • Returns fluids to circulatory veins near the heart
  7. What are the 2 lymph ducts?
    • Right lymphatic duct
    • Thoracic duct
  8. What materials are returned to the blood?
    • Water
    • Blood Cells
    • Protiens
  9. What harmful materials enter the lymph vessels?
    • Bacteria
    • Viruses
    • Cancer Cells
    • Cell Debris
  10. What do the lymph nodes do, and how?
    • Filter lymph before its returned to the blood
    • Macrophages engulf and destroy foreign substances
    • Lymphocytes provide immune response to antigens
  11. What is the structure of a lymph node?
    • Cortex - outer part containing follicles (collection of lymphocytes)
    • Medulla - Inner part containg phagocytic macrophages
    • Less than 1 inch long
  12. How does lymph flow through nodes?
    • Enters afferent lymphatic vessels
    • Flows through sinuses
    • Exits efferent lymphatic vessels
    • Fewer efferent than afferent causes back-up
  13. What are the "other" lymphoid organs?
    • Spleen
    • Thymus
    • Tonsils
    • Peyer's Patches
  14. What does the spleen do?
    • Filters bloood
    • Destroys worn out blood cells
    • Forms blood cells in the fetus
    • Acts as a blood reservoir
  15. What does the thymus do?
    • Produces hormones to program lymphocytes
    • Functions at peak levels during childhood
  16. What do the tonsils do?
    • Trap and remove bacteria and other foreign materials
    • Tonsillitus is caused by bacterial congestion
  17. What do Peyer's Patches do?
    Capture and destroy bacteria in the small intestine
  18. What are Mucosa-Associated Lymphatic Tissues (MALT)?
    • Protects respiratory and digestive tracts
    • Peyer's Patches
    • Tonsils
    • Other small lymphoid accumulations
  19. What is the body's 2 systems for defense against foriegn materials?
    • Nonspecific defense system - protects against a variety of invaders, responds immediately
    • Specific defense system - immune system, specific defense required for each type of invader
  20. What are nonspecific body defenses?
    • Surface coverings - skin, mucous membranes
    • Specialized human cells
    • Chemicals produced by the body
  21. What is the skin?
    • Physical barrier to foreign materials
    • pH of skin is acidic to inhibit bacterial growth
    • Sebum is toxic to bacteria
    • Vaginal secretions are very acidic
  22. What does the stomach mucosa do?
    • First line of defense
    • Secretes hydrochloric acid
    • Has protien digesting enzymes
  23. What are the defensive cells of the lymphatic system?
    • Phagocytes - neutrophils and macrophages
    • Engulfs foriegn material into vacuoles
    • Enzymes from lysozyme digest material
  24. What do phagocytes do?
    • Lyse and kill cancer cells
    • Destroy virus-infected cells
  25. What is the lymphatic systems second line of defense?
    • Inflammatory Response
    • Triggered when body tissues are injured
    • Redness
    • Heat
    • Swelling
    • Pain
  26. What are the functions of inflammatory response?
    • Prevents spread of damaging agents
    • Disposes of cell debris and pathogens
    • Sets the stage for repair
  27. What is fever?
    • High body temperature
    • Increases speed of tissue repair
    • Inhibit release of iron and zinc from liver that bacteria need
    • Hypothalmus reset by pyrogens
  28. What is the immune system?
    • Antigen specific defense
    • Systemic - not limited to infection site
    • Has memory - recognized and mounts stronger attack the next time there is infection
  29. What are the types of immunity?
    • Humoral - antibody mediated, cells produce chemicals for defense
    • Cellular - cell mediated, cells target virus infected cells
  30. What are antigens (nonself)?
    • Substance capable of igniting an immune response
    • Foreign particles
    • Nucleic acids
    • Large carbohydrates, and some lipids
    • Pollen grains
    • Microorganisms
  31. What are self-antigens?
    • Human cells have many surface protiens
    • Body usually doesn't attack itself
    • Our cells in another persons body could cause an immune response
    • Limits donors for transplants
  32. What are allergies?
    • Small molecules that bind with our own cells
    • The immune system is harmful due the body attacking its own cells
  33. What are the cells of the immune system?
    • Lymphocytes - B lymphocytes bone morrow, T lymphocytes thymus
    • Macrophages - arise from monocytes, widely distributed in lymph organs
  34. Characteristics of humoral immune response:
    • B lymphocytes bind to specific antigens
    • Large number of clones are produced
    • Most B cells become plasma
    • Produce antibody's to destroy antigens
  35. What is a secondary response?
    • Memory cells are long lived
    • Rapid response
    • Secondary response is stronger and longer lasting
  36. What is active immunity?
    • B cells enounter antigens and produce antibodies
    • Naturally or artifically acquired
  37. What is passive immunity?
    • Antibodies obtained from someone else
    • Naturally from mother to child
    • Artifically from immune serum or gamma globulin
  38. What are monoclonal antibodies?
    • Antibodies prepared for clinical testing, produced from a single cell line
    • Diagnose pregnancy and treatment for hepatitis and rabies
  39. What are antibodies?
    • Soluable protiens secreted by B cells
    • Carried in blood plasma
    • Binds specifically to an antigen
  40. What is the structure of an antibody?
    • Four amino acid chains linked by disulfide bonds
    • Two identical amino acid chains are linked to form a heavy chain
    • Two identical chains are light chains
    • Specific antigen binding sites are present
  41. 5 antibody classes:
    • IgM - fix complement
    • IgA - mainly in mucus
    • IgD - activation of B cells
    • IgG - can cross placental barrier
    • IgE - involved in allergies
  42. How do antibodies inactivate antigens?
    • Complement fixation
    • Neutralization
    • Agglutination
    • Precipitation
  43. How does cell mediated immune response work?
    • Antigens must be presented by macrophages to an immnocompetent T Cell
    • T cells must recognize nonself and self
    • After antigen binding, different classes of cells are produced
  44. 3 types of T-Cell clones
    • Cytotoxic T cells - kill infected cells, insert toxic chemical
    • Helper T cells - Recruit other cells to fight, interact with B cells
    • Supressor T cells - keeps immune response from overacting
  45. 4 types of grafts:
    • Autografts - tissue transplant on same person
    • Isograts - tissue transplant from identical twin
    • Allografts - tissue taken from unrelated person
    • Xenografts - tissue taken from different animal species
  46. Types of hypersensitivities:
    • Immediate hypersensitivity - IgE, reacts in seconds, anaphalactic shock
    • Delayed hypersensitivity - T cells, reacts within 1 - 3 days
  47. Immunodeficiencies
    • Congenitcal or acquired
    • Includes Aids
  48. Autoimmune Diseases:
    • Immune system does not distinguish "self"
    • T lymphocytes attack own tissues
    • Multiple Sclerosis
    • Juvenile Diabetes
    • Rheumatoid Arthritis
    • Systemic Lupus
Card Set
Lymphatic System
Lymphatic System1