IMMUNOLOGY

Detailed explanation-1: -Skin, tears and mucus are part of the first line of defence in fighting infection. They help to protect us against invading pathogens. You have beneficial bacteria growing on your skin, in your bowel and other places in the body (such as the mouth and the gut) that stop other harmful bacteria from taking over.

Detailed explanation-2: -First line of defence The surfaces of the body – the skin, digestive system, and the lining of the nose – are covered by a community of microbes called the normal body flora. They help protect the host from becoming infected with more harmful micro-organisms by acting as a physical barrier.

Detailed explanation-3: -Epithelial tissue, or skin, is an animal’s first line of defense against environmental challenges. It covers all exterior and interior surfaces of the body, like its cavities, tubes, organs and blood vessels, including the respiratory, reproductive, urogenital and gastrointestinal tracts.

Detailed explanation-4: -The macrophages and neutrophils of the innate immune system provide a first line of defense against many common microorganisms and are essential for the control of common bacterial infections.