T-lymphocytes and cell mediate immunity

• What are antigens?

  Parts of a cell recognized by the immune system
• How do antigens stimulate an immune response?

  They trigger the production of antibodies
• What type of cells are lymphocytes?

  White blood cells involved in immunity
• What is the effect of lymphocytes in the immune response?

  They have slower but longer-lasting effects
• Where are lymphocytes produced?

  In the bone marrow from stem cells
• What are the two types of lymphocytes?

  • T-lymphocytes
  • B-lymphocytes
• What is the role of T-lymphocytes?

  Involved in the cell-mediated immune response
• Where do T-lymphocytes mature?

  In the thymus gland
• What is the role of B-lymphocytes?

  Involved in the humoral immune response
• Where do B-lymphocytes mature?

  In the bone marrow
• What is cell-mediated immunity?

  • T-lymphocytes distinguish invader cells from self-cells
  • They use antigens for recognition
  • Involves rapid division and cloning of T-cells
• What happens during phagocytosis in cell-mediated immunity?

  Antigens are placed on phagocyte membranes
• How do T helper cells respond to antigens?

  Receptors fit onto the antigens precisely
• What is the result of T helper cell activation?

  Rapid division by mitosis forms clones
• What do cloned T cells develop into?

  Memory cells and other functional cells
• What functions do cloned T cells perform?

  • Develop into memory cells
  • Stimulate phagocytosis
  • Stimulate B cells to divide and secrete antibodies
  • Activate cytotoxic T cells
• What do cytotoxic T cells do?

  They kill abnormal body cells infected by pathogens
• How do cytotoxic T cells kill infected cells?

  By producing perforin to create holes
• What effect does perforin have on infected cells?

  Makes the cell membrane permeable to substances
• What happens to a cell after perforin is produced?

  The cell becomes freely permeable and dies