Chemical barriers against infection
Chemical secretions are produced against invading pathogens. Secretions include:
- stomach acid
- tears
- saliva
- mucus
Stomach acid
Stomach acid is a chemical barrier against infection. It is hydrochloric acid and is strong enough to kill any Microorganism that causes disease. that have been caught in Slimy white protein, which lines the respiratory tract and alimentary canal. in the airways or consumed in food or water.
Tears and saliva
Both tears and saliva have enzymes that destroy bacterial cells by breaking down their cell walls. These enzymes are called Enzymes found in tears that destroy bacterial cells.. Like stomach acid, they are a form of chemical defence against infection.
Irritation of the membrane that surrounds the eye. can occur if pathogens are not killed by lysozymes
Mucus
Mucus is a sticky substance secreted by Cells in the lining of the airways that produce mucus to trap dust and pathogens. in the The windpipe, the tube that leads from the mouth towards the lungs.. Foreign particles and pathogens adhere to the surface and Tiny hair-like projections from a cell that usually allow it to move a substance past the cell (for example, in the bronchioles in the lungs). sweep the mucus away from the lungs.