Ch 14 Lymphatic and Immune Systems

• lymph characteristics 


  clear watery fluid that surrounds body cells and flows in a system of lymph vessels throughout the body

  • originates in blood
  • rich in lymphocytes and monocytes
  • flows in lymph capillaries and vessels
  • liver, spleen, thymus, and nodes
  • absorbs lipids in the intestine
• function of the lymphatic system 


  1. transport proteins and fluid that have leaked, back to bloodstream
  2. lymph vessels absorb lipids from intestine and transport the to bloodstream
  3. lymphocytes and monocytes protect the body by mounting a cellular attack on foreign cells and organisms
• lymphatic system anatomy 


  • capillaries, vessels, lymph nodes
  • cervical (neck), axillary (armpit), mediastinal (chest), mesenteric (intestinal), paraaortic (lumbar), inguinal (groin)
• macrophages


  phagocytose foreign substances
• B lymphocytes (B cells)


  produce antibodies

  • mature in the bone marrow
• T lymphocytes (T cells)


  attack bacteria and foreign cells

  • originate in the thymus gland
• functions of the spleen 


  1. destroys old red blood cells
  2. filters microorganisms and other foreign material out of the blood
  3. activates lymphocytes during blood filtration
  4. B cells produce antibodies
  5. T cells attack foreign materials
  6. stored blood, especially erythrocytes and platelets
• functions of the thymus gland 


  1. provides immunity in fetal life and in early years of growth
  2. makes cells immunocompetent in early life
  3. early removal from an animal impairs its ability to make antibodies and produce cells to fight antigens
• what is the leukocyte portion of the immune system consist of 


  neutrophils, monocytes, and macrophages
• what are the lymphoid organs of the immune system


  1. lymph node
  2. spleen
  3. thymus gland
  4. tonsils
  5. adenoids -> produce lymphocytes and antibodies
• what does immunity mean


  the body's ability to resist foreign organisms and toxins that damage tissues and organs

  • can be natural or adaptive
• natural immunity 


  resistance present at birth

  • not dependent on prior exposure to an antigen
  • phagocytosis
  • macrophages
  • natural killer cells
• adaptive immunity


  active by contracting disease, vaccination, or stem cell transplant
• what are B lymphocytes responsible for 


  humoral immunity

  • originate in bone marrow from stem cells
  • B cells produce antibodies after exposure to specific antigens (virus and bacteria)
  • matures into plasma cell that produces antibodies called immunoglobulins to block the effects of antigens
• are are T lymphocytes responsible for 


  cell-mediated immunity and does not involve antibodies
• what do cytotoxic T cells (T8 cells) do 


  attack to and directly kill antigens
• what is cytokines and what is its function


  it is interferons and interleukins that help cells respond to antigens
• what do helper T cells do 


  promote antibody synthesis by B cells and stimulate other T cells
• what do suppressor T cells do 


  inhibit B and T cells and prevent them from attacking the body's own good cells
• what do dendritic cells do 


  • macrophage derived from monocytes
  • recognize and digest foreign antigens
  • present antigens on the surface to stimulate B and T cells
  • transfer immunity by exposing dendritic cells in culture then transfuse them and stimulate T and B cells
• vaccines 


  contain antigens from the patient's tumor cells

  • stimulate T cells to recognize and kill the cancerous cells
  • active immunotherapy
• dendritic cells


  cultured and exposed outside the body and reinfused
• monoclonal antibodies (MoAb)


  multiple copies of cells or genes that kill tumor cells

  • passive immunotherapy
• donor lymphocyte infusions 


  T cells, infused after allogeneic stem cell or bone marrow transplant, attack tumor (leukemia treatment)

  • passive immunotherapy
• adenoids 


  mass of lymphatic tissue in the nasopharynx
• antibody 


  protein produced by B cells to destroy antigens
• antigen


  substance that the body recognizes as foreign

  • evokes an immune response
• axillary nodes 


  lymph node in the armpit
• B cell (B lymphocyte)


  matures into a plasma cell to secrete antibodies
• cell-mediated immunity 


  T cells that respond to antigens and destroy them
• cervical nodes 


  lymph nodes in the neck region
• complement system


  proteins in the blood that help antibodies and kill their target
• cytokines


  proteins secreted by cytotoxic T cells to aid in antigen destruction
• cytotoxic T cell (CD8+ T cell)

  lymphocyte that directly kills antigens
• dendritic cell


  antigen presenting cell

  • shows T and B cells what to attack
• helper T cell (CD4+ T cell)


  lymphocyte that aids B cells and stimulates T cells
• humoral immunity 


  B cells produce antibodies after exposure to specific antigens

  • type of adaptive immunity
• immunoglobulins 


  antibodies secreted by plasma cells in response to the presence of an antigen
• immunotherapy 


  use of immune cells, antibodies, or vaccines to treat or prevent disease
• inguinal nodes


  lymph node in the groin