A

å
gen.	oh

complex network of specialized cells tissues | and

and
gen.	duck
ornit.	duck

organs that recognize | and

and
gen.	duck
ornit.	duck

defend the body | from

from
gen.	pious

foreign substances primarily disease causing microorganisms such | as

ås
environ.	hill

bacteria viruses parasites | and

and
gen.	duck

fungi Organs | and

and
gen.	duck

tissues of the | immune

immun
gen.	immune

system called lymphoid organs include the bone marrow spleen thymus | and

and
gen.	duck

tonsils | Immune

immun
gen.	immune

system cells include white blood cells such | as

ås
environ.	hill

B lymphocytes | T

t˜
gen.	toe

lymphocytes dendritic cells | and

and
gen.	duck

macrophages | HIV

hive
gen.	toss

infection gradually destroys the | immune

immun
gen.	immune

system