American Academy of Professional Coders (AAPC) Practice Exam

What main function do mucous membranes serve?

1. Protection from physical damage

2. Absorption and secretion

3. Providing structural support

4. Facilitating movement between organs

The correct answer is: Absorption and secretion

Mucous membranes play a crucial role primarily in absorption and secretion. These membranes are found lining various cavities and organs of the body that are exposed to the external environment, such as the respiratory, gastrointestinal, and urogenital tracts. They produce mucus, a sticky secretion that serves several important purposes. Mucus helps protect these membranes by trapping pathogens and debris, thus preventing infections and facilitating the clearance of particulates. In addition, the secretions maintain moisture in these areas, which is essential for the proper function of the organs they line. In the gastrointestinal tract, for instance, mucus not only lubricates the contents for easier passage but also aids in digestive processes. Moreover, mucous membranes are involved in the absorption of nutrients and substances, particularly in the intestines, where they facilitate the uptake of digested food molecules into the bloodstream. This multifaceted function underscores the importance of mucous membranes in various physiological processes.