There are 3 areas of defense in our immunity system. The first consists of the outer body, such as our skin. The second line of defense is our mucus membranes in the body's orifices that secrete fluids necessary to trap foreign bodys and bacteria. There are also linings in the respiratory and digestive systems that secrete enzymes needed to fight germs and bacteria entering the body. Third is our immune system within that produces antibodies to fight off viruses and bacterias within all areas of the body. The strength of on'es immune response is based on the healthy maintenance in these 3 areas which are the result of living a healthy lifestyle of regular exercise, good diet, rest, and stress management.