Antibodies

Antibodies 1. IgM antibodies are the first to respond to an invading pathogen. They offer important protection during the early days of infection. These antibodies tend to stay in the bloodstream where they aid in killing bacteria.

2. IgG antibodies are the next to respond after IgM antibodies. These antibodies are formed in large quantities and work in the blood and tissues of the body. They bind to destructive pathogens so that the immune cells (for example macrophage) have an easier time ingesting them. IgG antibodies can pass from a mother to her unborn baby through the placenta.

3. IgA is produced along the surface linings of the lungs and intestines and is secreted in body fluids such as tears, saliva, and mucus. This antibody also protects against infection in the respiratory tract and intestines. IgA passes from mothers to newborns through breast milk.

4. IgE is normally present in trace amounts and is important in allergic reactions.

5. IgD may be present on the surface of B cells. IgD's function is to signal when the young B cells in the spleen are ready to be activated. By being activated, they are ready to take part in the defense of the body in the immune system.

Antibodies make pathogens easier to kill, by alerting the immune system that the germs need to be destroyed.