Immunity

Immunity

1. Immune Response

   • Phagocytosis
     • recognise foreign anitgen/bacteria
     • form Phagocytic Vacuole
     • lyszome enzymes secreted into vacuole
     • bacteria/antigen gets hydrolysed
     • antigen may get used for antigen presentation
   • T-Cells
     • Helper T-Cells
       • Stimulate B-Cells to secrete antibodies
       • Stimulate Cytoxic T-cells to kill abnormal cells
     • T-Memory Cells
       • Remember Antigens person was exposed to
   • B-Cells
     • Complementary to one antigen
     • Clonal selection- selection of correct antibody
       • Divide into plasma cells and antibodies are secreted
     • B-Memory cells remember complementary antibody for the antigen

2. Types of Response

   • Cellular
     • T-Cells & other immune system cells e.g. Phagocytes
   • Humoral
     • B-Cells and clonal selection (production of antibodies)

3. Primary & Secondary Response

   • Primary
     • Slow response
       • No T-memory cells
       • No B-memory cells
     • Some T & B Memory cells produced
   • Secondary
     • Faster
       • Memory cells are present from primary response
       • Faster clonal selection
       • Faster and more anitbodies produced

4. Types of Immunity

   • Active
     • Natural - immune after catching a disease
     • Passive - Immune after vaccination
   • Passive
     • Natural - baby getting antigens from mother
     • Artificial - injection of antibodies produced by someone else

5. Antigenic Vriation

   • Same Bacteria different antigen
     • Slower immune response
     • Primary Response for each strain