immune response to disease Flashcards
2.62
what does the immune system protect us from?
pathogens
what are the main components of the immune system?
white blood cells
how do white blood cells protect us?
phagocytes
producing antibodies
how do phagocytes engulf pathogens?
phagocytosis
what are the 2 main types of white blood cells?
phagocytes
lymphocytes
explain phagocytosis in 6 steps?
1) phagocyte recognises pathogen
2) phagocyte engulfs pathogen in a process known as phagocytosis
3) the lysozymes containing enzymes move towards the pathogen
4) enzymes break down pathogen
5) useful materials are absorbed
6) waste products are removed from the phagocyte
what type of cell membrane do phagocytes have?
a sensitive cell membrane that can detect chemicals produced by pathogenic cells
what type of response do phagocytes have?
a non-specific immune response
how can phagocytes be recognised through the microscope?
their multi-lobed nucleus and their granular cytoplasm
how can lymphocytes be recognised under the microscope?
their large round nucleus which takes up the whole cell and their clear, non-granular cytoplasm
what do lymphocytes produce?
antibodies
what are antibodies?
Y-shaped proteins with a shape that is specific (complementary) to the antigens on the surface of the pathogen
what type of response are lymphocytes producing antibodies?
a specific type of immune response as the antibodies produced will only fit one type of antigen on a pathogen
what is formed when antibodies attach to the antigens?
agglutination (clumping together)
what does agglutination mean?
the pathogenic cells cannot move very easily
at the same time, chemicals are released that signal to phagocytes that there are cells present that need to be destroyed
what do lymphocytes also produce?
antitoxins to neutralise toxins released by pathogens
what is the role of the immune system once a pathogen has entered the body?
prevent the infectious organism from reproducing and to destroy it
when does an organism have immunity?
when they have sufficient levels of antibodies to protect it from a particular disease
what do lymphocytes allow?
organisms to build up an immunity towards certain diseases
what do lymphocytes multiply to produce?
antibodies
what do antibodies do?
inactivate viruses
how do lymphocytes build up immunity?
1) lymphocytes detect pathogen’s antigens
2) lymphocyte identifies the correct type of antibody to make, which is complementary to the pathogen’s antigen
3) lymphocyte releases large numbers of correct antibody
4) pathogens either clump together resulting in death or the antibodies trigger phagocytes- some pathogens can even burst
5) lymphocytes produce cells that produce lots of the antibody very quickly if they detect the same pathogen again. these are called memory cells
what are anti-toxins?
some antibodies are specialised to combat toxins, chemicals released by the pathogen which cause cell damage
