cell recognition and immune system

• phagocytosis

  process by which a cell engulfs material either to digest and therefore destroy the foreign material it is a non-specific response and will destroy any foreign material in the body carried out by white blood cells made in bone marrow
• how does presentation of virus antigen leads to the secretion of an antibody against this virus antigen

  lysosomes release enzymes which digest/ engulf pathogens. they stimulate release of helper T cell and b cells which divide by mitosis. T cells bind to antigen form clonal cells
• describe how phagocytosis of a virus leads to presentation of its antigen

  -phagocytosis is where a cell engulfs digests material and destroying the pathogen the lysosome fuses with phagosome casing pathogen to be digested by enzymes by hydrolysis therefore leading to presentation of antigens on the cell surface membrane
• humoral immunity

  results in production of proteins called "immunoglobulins" or "antibodies"

  body exposed to "foreign" material termed "antigen" which may be harmful to body: virus, bacteria etc.

  antigen has by passed other protective mechanisms first and second line of defence
• B-lymphocytes

  B cells are associated with humoral immunity

  mature in bone marrow then carried to lymphoid tissue by blood stream and lymphatic circulation

  this process of maturation and migration takes place throughout life

  other lymphocytes can be generated by mitosis of B lymphocytes resident in lymphoid tissues
• B cells and humoral immunity

  some T cells produce factors to stimulate B cells to divide

  there is millions of different B cells each producing a different type of antibody

  when an antigen enters the blood there will be a matching B cell with matching antibody

  B cells divide by mitosis

  Humoral immune response
• cell mediated immunity

  bone marrow -> lymphocyte ->thymus -> thymus -> T cell receptor -> viral infected cell/ cancer cell/ red blood cell OR T CELLS to cytotoxic T cells
• plasma cells

  secrete antibodies

  survive for only a few days

  primary immune response

  responsible for immediate defence against infection
• memory cells

  -do not produce antibodies directly

  -provide long term immunity

  -secondary immune response

  -can live for several decades

  -more rapid and more intense

  -divide into plasma cells and new memory cells
• what happens when B cell is confronted with an antigen for the first time

  B cells produce a memory cell called primary response
• primary immune response

  slow, taking days or even weeks to recruit enough plasma cells to bring on infection
• antigen

  pre sent on the surface trigger an immune response
• antibody

  when body is exposed to foreign material
• TYPE AB BLOOD

  recieve blood from anyone theres no anti A o r anti B to cause agglutination universal recipient
• type 0 blood

  blood cells can be given to anyone in an emergency has no antigens to lead to agglutination
• agglutination

  if type A is mixed with B and looked at under a microscope red blood cells will be stuck together in clumps anti A antibodies stick type A cells together anti B antibodies stick type B together
• passive immunity

  introduced from outside antibodies traveled across the placenta from the maternal blood to the fetal blood last only only several weeks
• active immunity

  antibodies produced by bodies own immune system
• whats a vaccine

  a suspension of antigen material that are intentionallu put into the bod to induce artificial active immunity
• two types of vaccinations

  -live attenvated

  -inactivated
• plasma cells

  secret antibodies

  survive for only a few days

  primary immune response

  responsible for immediate defense against infection
• memory cells

  do not produce antibodies directly

  provide long term immunity

  secondary immune response

  can live for several decades

  more rapid and more intense divide into plasma cells and new memory cells