Adaptive immunity displays memory, responding better after the first exposure to an invader, even if the second exposure is years later.
This implies that somewhere in the body is some kind of “storehouse” of antigens, or antigen descriptions. Where is this?
In a nifty place under the sternum (the rod down the middle of your ribcage).
Official name forthcoming…
Inkz
My immunology text book is across the street but the quick answer is lymph nodes. The cells that recognize the antigens are concentrated there.
From the way MY immune system responds, I would say it stores the data in that room where the Ark was taken in ‘Raiders’ 
The gland under the sternum referred to is the thymus. (Not to be confused with the thyroid)
The immune system “memory” is stored in lymphocytes. After each exposure to an antigen, not only are there more lymphocytes circulating which produce antibodies specific to that antigen, but the antibodies react more strongly to the antigen (more of the cells make antibodies with higher binding affinities for that particular antigen).
Over time, fewer of the lymphocytes remain in circulation, but re-exposure stimulates the existing cells to multiply.
Lymphocytes hang out in the spleen, the thymus, and the lymph nodes, and circulate in the blood stream as well.
Sue from El Paso
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