Immune
System
Third Line of Defense
– Specific Immunity

 called into action when
nonspecific methods are not
enough and infection becomes
widespread

FUNCTION
 mounts attacks against
specific foreign substances
specific
foreign
substances

FEATURES…
…

 Self/non-self discrimination
- it normally distinguishes between self
and non-self and only reacts against
non-self.
non-self

 When a nonself (foreign) body
is detected, mitotic activity
in B and T lymphocytes is
stimulated

 Whilemitosis is occurring, the
daughter populations become
subdivided into…