Immunity

• humans have two ways of protecting themselves from pathogens: preventing them from entering the body or killing those that make it into the body
• innate immunity: our natural immunity, non-specific, present from birth
• acquired immunity: develops due to exposure to pathogens, specific, has a memory of past pathogens
• phagocytes: white blood cells that ingest and kill pathogens, arrive at site of infection and leads to inflammation, non-specific
• lymphocytes: white blood cells that ingest/recognise and kill specific pathogens, have a memory of pathogens they have fought before, specific
• three types of lymphocytes: helper t cells, killer t cells, b cells
• helper t cells: produce chemical signals to attract immune cells and help turn on the b and killer t cells
• killer t cells: make weapons to kill pathogens and infected body cells
• b cells: make antibodies for their specific pathogen