 TONSILS. Collections of lymph tissue in the back of
the throat filter out organisms that cause infection. |
 |
THYMUS. Organ in which new white blood cells grow up, developing
specialized functions. |
 LIVER. White blood cells in this "filter"
organ remove organisms from the blood as it passes through. |
SPLEEN. Removes abnormal cells from circulation. |
MUCOUS MEMBRANES in the respiratory and gastrointestinal tracts
repel organisms and allergens and contain immunoglobulins that
battle organisms that try to penetrate. |
 LYMPH
NODES. Act as "filters" and produce antibodies to destroy
invading organisms or abnormal cells. |
 BONE MARROW. All immune-system cells start
out here. White blood cells (neutrophils, lymphocytes) are formed,
then released into circulation. |
SKIN: Keeps organisms and allergens from
entering the body. |
