Communicable diseases

• What are the two responses of the specific immune system?

  Cellular response and humoral response
• What’s the difference between the specific and non-specific defence system?

  The specific is slower and produces a unique response for each type of pathogen, providing long-term immunity
• Where are lymphocytes produced?

  In the bone marrow
• Where do T cells mature?

  Thymus gland
• Where do B cells mature?

  Bone marrow
• What cells are involved in cellular response?

  T cells
• What cells are involved in humoral response?

  B cells
• What do T cells do?

  They respond to antigens presented on body cells in the cellular response
• What do B cells do?

  Produce antibodies found in body fluids or humors in the humoral response
• What are the different types of t cells?

  t helper cells, t killer cells, t regulator cells, t memory cells
• What are the stages of cellular response?

  1. Macrophages engulf pathogens and present their antigens on the cell-surface becoming antigen-presenting cells
  2. T helper cells with complementary receptors bind to these antigens
  3. This activates the t helper cells to divide by mitosis to form genetically identical clones
  4. The cloned T cells carry out different functions. They can develop into memory cells, t killer cells, stimulate phagocytosis and stimulate the division of B cells
• What do memory cells do?

  Circulate the body to provide long-term immunity
• What do cells produce to stimulate phagocytosis?

  Interleukins
• What cells are involved in the humoral response?

  B cells, plasma cells, memory cells, t helper cells
• What are the stages of the humoral response?

  1. B cells with a complementary antibody binds to the antigens on a pathogen
  2. B cell engulfs the pathogen and presents its antigens on the cell-surface membrane becoming an APC
  3. Clonal selection: activated t-helper cells bind to the B cell, causing activation of this B cell for cloning
  4. Clonal explansion: the activated B cell divides by mitosis to form plasma and memory cell clones
  5. Cloned plasma cells produce and secret the specific antibody thats complementary to the antigen on the pathogen’s surface. These antibodies attach to the antigens on the pathogens and destroy them
  6. The memory cells circulate the blood and tissue fluid, ready to divide if body is re-infected by the same pathogen
• What is clonal selection?

  The B cell with the correct antibody is selected by cloning by being T-helper cell binding to it and activating it
• What is clonal expansion?

  The division of specific B cells by mitosis to produce genetically identical clones