Question

Which of the following is an example of a physical barrier in the innate immune system?

• A. Saliva
• B. Mucous coating of the gastro-intestinal tract
• C. Natural killer lymphocytes
• D. Interferons

Answer 1

Answer:

B. Mucous coating of the gastro-intestinal tract

• Physical barriers provide a structural block to the entry of foreign agents. This includes the skin and the mucous coating of the respiratory, gastro-intestinal, and urino-genital tracts, which trap microbes.