Thin epithelial surfaces are necessary for the normal physiological functions of the body's mucus membranes (ie absorption and gas exchange).They are therefore more susceptible to infection. But it's ok as the body uses alternative protective mechanisms in these areas: | Thin epithelial surfaces are necessary for the normal physiological functions of the body's mucus membranes (ie absorption and gas exchange).They are therefore more susceptible to infection. But it's ok as the body uses alternative protective mechanisms in these areas: |