Which of the following statement regarding different barriers of inna…

Acid present in the stomach, saliva in the mouth, tears from the eyes prevent the growth of microorganisms and constitute physiological barriers of our body.

Mucous membrane lining the respiratory gastro intestinal and urinogenital tracts help in trapping the microbes and constitute physiological barriers of our body.

Certain types of leucocyte such as polymorpho nuclear leucocytes and lymphocytes such as natural killer cells constitutes cellular barriers of our body.

Virus infected cells secret proteins called interferons which protect non infected cells from further viral infection and constitute cytokine barriers of our body.