After being wounded, what type of cells (part of the second line of defense) begin to fight off bacteria?
How do these cells know that the bacteria have penetrated through the skin?
Lymphocytes, which are divided to T and B cells, begin to fight off bacteria. After the bacteria penetrate through the skin, the B-cells are activated and create antibodies for this specific bacteria. Then T cells are activated and migrate to the site of infection, where there is maximum concentration of the antigens.