Goblet cells are most abundant in which mucosal surfaces?

• A. Respiratory and intestinal mucosa.
• B. Skin and oral mucosa.
• C. Genitourinary mucosa.
• D. Nervous tissue.

Answer: (A)

Goblet cells produce mucin, which combines with water to form mucus that lubricates and protects mucosal surfaces. They are most abundant on surfaces where a continuous mucus layer is essential for trapping particles and pathogens and for smooth passage of contents—namely the respiratory and intestinal tracts. In the respiratory mucosa, goblet cells sit among the pseudostratified ciliated columnar epithelium and continually supply mucus that is moved out by cilia. In the intestinal mucosa, they are a hallmark of the simple columnar epithelium, especially in the colon, where mucus protects the epithelium from mechanical and chemical stress and aids lubrication. Skin lacks mucous-secreting cells because its barrier is keratinized rather than mucus-covered, and nervous tissue isn’t mucosal tissue. The genitourinary mucosa has mucous secretion in places, but goblet cells aren’t as characteristic there. So, goblet cells are most abundant in respiratory and intestinal mucosa.