ANATOMY

Detailed explanation-1: -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.

Detailed explanation-2: -The skin prevents the entry of microbes into the body. Skin secretes oil from the oil glands and sweat from the sweat glands that kill the microbes. Thus, skin acts as a physical barrier and prevents various infections.

Detailed explanation-3: -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-4: -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.