ANATOMY

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: -The first line of defence is your innate immune system. Level one of this system consists of physical barriers like your skin and the mucosal lining in your respiratory tract. The tears, sweat, saliva and mucous produced by the skin and mucosal lining are part of that physical barrier, too.

Detailed explanation-3: -Overview. Your body’s first line of defense includes the skin and other barriers that keep pathogens out of your body. The first line also includes tears, mucus, cilia, stomach acid, urine flow, and friendly bacteria.

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: -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.