Beginning of Essay
The graph shows the response of the human immune system to the exposure of an antigen in two phases. The first phase is that of a primary response to the initial attack. The second response is very rapid, subsequent to attacks from the same antigen. The specifi ....

Middle of Essay
.... factory. It can make up to 30,000 antibodies a second. The second type of cell being made in period I is a memory cell. They also produce antibodies, however they live for long periods of time (up to a lifetime), compared to a plasma cell that lives only a few days. Memory cells are made so they can recognize this same antigen if it were to ever reenter the body again. Interactions between T cells are also known as the cell-mediated response. T cells are not just active against viruses and bacteria, but they also interact with eukaryotic cells. There are three types of T cells: helper T cells, suppressor T cells, and cytotoxic T cells. The T ....