To which type of barriers under innate immunity, do the saliva in...

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.