Comments on: How is the immune system able to protect the body against all potential invaders without knowing in advance?

By: Henry

Henry — Tue, 10 Nov 2009 22:04:59 +0000

your immune system has the ability to differentiate your own cells as oppose to foreign cells by a protein on cells called MHC. When encountering a new invader, cells that are not recognized by the cytotoxic (killer) T cells are attacked and killed.

Helper T cells then activate B cells which secrete anti-bodies which will mark the new invaders so other T cells can recognize it and kill it.

If the same pathogen invades again, memory B cells then be able to quickly recognize it. Antibodies would then be quickly produced and T cells would quickly kill off the pathogen without us feeling "sick."
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By: saffronesque

saffronesque — Tue, 10 Nov 2009 21:32:59 +0000

The genes found in B lymphocytes are highly variable. When you still very young, your body filters out any lymphocytes that would attack your own cells. The remaining cells, billions of different kinds of B cells survive. When an infectious agent or foreign molecule is found in your body, the appropriate B cell multiplies rapidly to produce antibodies specific to that infectious disease or molecule. After the cells have been activated some become memory cells that will rapidly multiply if that same infectious agent again enters your body. This process is called the clonal selection theory if you want to search the data bases for more information.
References :
Biology instructor for 40 years

By: Adam K

Adam K — Tue, 10 Nov 2009 21:16:59 +0000

Well, memory cells remember some viruses/bacteria. Also, the white blood cells can destroy illnesses through devouring them, senting out antigens etc.
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