topic two biology

• Co-stimulation


  Interaction between CD80/86 on antigen presenting cells and CD28 on T cells
• Acquired immunodeficiency syndrome (AIDS) is a syndrome caused by the human immunodeficiency virus (HIV)
• HIV


  Retrovirus that attacks and destroys CD4+ T helper cells
• There are two main types of HIV: HIV-1 and HIV-2, with HIV-1 being more common and widespread
• Maternal-fetal immune tolerance


  The placenta acts as a barrier and the mother's immune system becomes suppressed during pregnancy to prevent rejection of the fetus
• Autoimmune diseases


  Conditions where the immune system attacks the body's own tissues
• Organ transplant rejection


  1. Donor and recipient tissues are matched for compatibility

  2. Immunosuppressant drugs are used to prevent rejection
• Blood transfusion compatibility


  Blood types must be matched to prevent antibody-mediated destruction of red blood cells
• Complications of hemolysis (red blood cell destruction) include hyperkalemia, hyperphosphatemia, hemoglobinemia, and kidney damage
• Humoral immunity


  Immunity mediated by antibodies secreted into body fluids
• Cellular immunity


  Immunity mediated by T lymphocytes that directly attack and destroy target cells
• Antigen


  A piece of a foreign invader (e.g. bacteria) that the immune system recognizes
• Antigen presenting cell


  A cell that displays an antigen on its surface to be recognized by lymphocytes
• MHC


  A molecule on the surface of antigen presenting cells that displays the antigen
• B lymphocyte


  A lymphocyte that can differentiate into plasma cells to secrete antibodies
• T lymphocyte


  A lymphocyte that directly attacks and destroys target cells
• T helper lymphocyte


  A T lymphocyte that helps activate and coordinate the immune response
• T cytotoxic lymphocyte


  A T lymphocyte that directly kills target cells
• T regulatory lymphocyte


  A T lymphocyte that suppresses immune responses to prevent autoimmunity
• Antibody


  An immunoglobulin molecule secreted by plasma cells that binds to and neutralizes antigens
• Types of antibodies


  • IgM
  • IgA
  • IgG
  • IgE
  • IgD
• IgM


  • Large, cannot cross placenta, good at activating complement
• IgG


  • Most abundant, small, crosses placenta, opsonizes bacteria, activates complement
• IgA


  • Found in mucous membranes, first line of defense
• IgE


  • Involved in allergic reactions and defense against parasites
• IgD


  • Function unknown, produced first on naive B cells
• Primary immune response


  Involves IgM antibodies
• Secondary immune response


  Involves IgG antibodies
• Lymphoid stem cells give rise to T and B lymphocytes
• Naive B cells can differentiate into memory B cells or plasma cells
• Plasma cells secrete antibodies
• has invaded what's that fungus i'll destroy the fungus face to face baby self-mediated immunity what is this cancer i'll try to kill it face to face i am not secreting any antibodies into any fluids this is not who i am
• B lymphocytes


  They grow in the bone marrow and in birds they mature in the bursts of fabricious
• T lymphocytes


  They mature in the thymus gland
• Types of T lymphocytes


  • T helper
  • T cytotoxic
• T cytotoxic


  Toxic through the cell, can destroy fungus cell, cancer cell, virus infected cell
• T helper


  Helps all kinds of cells, helps T cytotoxic, helps T suppressor/regulatory, helps B lymphocytes
• T suppressor/regulatory cells


  Prevents T cytotoxic from killing your own cells, tells T cytotoxic to attack foreigners not self
• If there are problems with T regulatory/suppressor cells, T lymphocytes will attack your own cells leading to autoimmune diseases like lupus
• Antigen


  A foreign substance that stimulates the immune system to produce an immune response