Q: How does the specific
defense of the immune system work? A: When a pathogen
enters the system, it is investigated by B-cells
specific for many different things. If a B-cell happens to be present
which is specific for that pathogen, the cell will replicate and
then produce its particular kind of antibodies.
These antibodies bind to the antigens
on the pathogens, causing the antigens to
clump together. These clumps are then destroyed by the rest of the
immune system. If the pathogen
(most likely a virus) enters human body cells,
the antigens get broken down inside the cell, and the pieces of
the antigen are presented on the surface of the cell. If a T-cell
is present which is specific for those pieces specific for that
pathogen, the T cell will
replicate and then bond to these infected cells and kill them to
keep the virus inside the cell from spreading. The immune
system reacts faster to a pathogen if
its been exposed to that pathogen before.