what is the article about?
The immune system
how is it defined?
system of many biological structures
what must it do to work correctly?
detect a wide variety of agents
are they also called something else?
pathogens
is the worm helpful?
No
do pathogens change?
Yes
slowly?
No
how are brains protected?
brain barriers separate the peripheral immune system from the neuroimmune system
are they solid?
No
what are they composed of?
blood and fluids