Describe ways in which the body prevents entry of microorganisms

The first line of defence is the skin. This forms a physical barrier that prevents any microorganisms from getting into the body. Acid in the stomach, due to the low pH, is another defence the body has. This can kill many microorganisms we might ingest on our food or in our drinks. Also, hairs and mucus in the noise, as well as in the ear with earwax can trap microorganisms. These can work in combination with ciliated cells, which are cells with a hair like protrusion, that can waft mucus to the throat from the bronchi or trachea to be swallowed where the acidic environment in the stomach will kill the microorganisms.