Immmmmune

Sure, I'll talk about immunity. What exactly are you confused on? The Body's response?

The basic breakdown of what happens during an infection is that the body works to recognize everything, including itself, by markers on the outside of the cell.

If a Macrophage discovers something that is not designated "self", it engulfs and digests it...but not completely. Some of the proteins or marks are displayed on the outside of the cell. The associated Tcells come over and recognize this as an infection, and begin to replicate so that there are many in the body, and send out a "seek and destroy" mission to erradicated the rest of the foreign objects.

This also triggers the associated B cells, which check the scene out and begin go replicate via mitosis. now you have a bunch of Bcells, which differentiate into plasma cells (and the antibodies). These are now in your bloodstream, ready to find more bacteria or infected macrophages in order to rid the body of the invaders.

since there are lots floating around, and they stick around for a while, they are called memory cells.

Make sense?

any more questions, please let me know asap
:D
and BREATHE