ANATOMY

Detailed explanation-1: -The innate immune system is the body’s first line of defense against germs entering the body.

Detailed explanation-2: -Skin is a barrier that serves as one of the body’s first lines of defense against harmful microbes. Specialized immune cells within skin tissue help to fight invading organisms. Yet the skin hosts diverse communities of beneficial bacteria, collectively known as the skin microbiota.

Detailed explanation-3: -The first line of defense against infection are the surface barriers that prevent the entry of pathogens into the body. The second line of defense are the non-specific phagocytes and other internal mechanisms that comprise innate immunity.

Detailed explanation-4: -The immune system has three lines of defence. The first line of defence is made up of barriers to prevent infection. The second line of defence is made up of responses to infection that apply generally to all pathogens. The third line of defence provides immunity against specific pathogens.

Detailed explanation-5: -Epithelial tissues cover most of the external and internal surfaces of the body and its organs. Inevitably, these tissues serve as first line of defence against inorganic, organic, and microbial intruders. Epithelial cells are the main cell type of these tissues.