ANATOMY

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

Detailed explanation-2: -The three lines of defense are barrier defenses, the innate immune system, and the adaptive immune system.

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 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: -Answer and Explanation: Fever is not the first line of defense; it is considered the second line of defense. Suppose the first line of defense couldn’t protect the body, and the pathogen still enters the body. In that case, the second line of defense protects the body, including fever, inflammation, and phagocytosis.