Question

An individual was exposed to a contagious disease but did not become infected. The agent was unable to enter the body and grow because it was stopped by the person's skin. This is an example of how a __________ can prevent disease.

Answer 1

The individual that was exposed to the disease did not get infected because their skin acted as a first line of defense (a physical barrier), against the pathogenic organism. This meant the pathogen could not lead to a disease within the individual.

Answer 2

This is an example of how a physical barrier can prevent disease. In this scenario the skin is the physical barrier. The agent was stopped by the person's skin and was unable to enter the body, grow and infect the person. Natural barriers that defend the body against organisms that can cause infection include the skin, mucous membranes, tears, earwax, mucus, and stomach acid.