Cells are tightly joined together, preventing bacteria from invading deeper tissues. Sloughing of dead cells prevents microbial population from continually increasing. The protein, keratin , fills the cells in the outer layers of the epidermis. C. Movement of body fluids dislodges microbes.
Perspiration also contains high concentrations of salt, creating a hypertonic environment.
Bile, produced by the liver, also disrupts the bacterial cell wall. Bile is secreted into the small intestine to aid in the digestion of lipids. Fatty acids are contained in the oil secreted from oil glands in the skin. It makes the skin slightly acidic. B cells, T cells, Natural Killer cells.