To which type of barriers under innate immunity, do the saliva in the mouth and the tears from the eyes,…

To which type of barriers under innate immunity, do the saliva in the mouth and the tears from the eyes, belong?
  1. Cytokine barriers
  2. Cellular barriers
  3. Physiological barriers
  4. Physical barriers

Solution

Innate immunity is the resistance to infection, which an individual possesses by virtue of his/her genetic and constitutional make up. Thus, it comprises all those defence elements with which an individual is born and, which are always available to protect a living body. Physiological barriers like body temperature, $\mathrm{pH}$ of the body fluid, and various body secretions (saliva, tears) prevent growth of many disease causing micro-organisms. Skin is the physical barrier of the body. Its outer tough layer the stratum corneum prevents the entry of bacteria and viruses.

Asked in: NEET 2008 (Screening)

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