Where are goblet cells and mucous glands most prominent in the airway tree?

• A. In the trachea and main bronchi (conducting airways)
• B. In the terminal bronchioles
• C. In the alveolar ducts
• D. In the nasal cavity only

Answer: (A)

Distribution of mucus-secreting cells along the airway is tied to the function of different airway regions. Goblet cells produce mucus, while mucous glands in the submucosa add to the mucus layer that coats the airway surface. This mucus traps dust, pathogens, and other particles, and the ciliated cells help move it out of the airways.

Both goblet cells and mucous glands are most prominent in the trachea and the larger bronchi, the conducting airways. They provide a substantial mucus-producing surface to keep these passages lined and protected. As you go to smaller, distal airways, goblet cells become scarce and mucous glands are fewer; the terminal bronchioles rely more on other secretory cells (like club cells), and the alveolar ducts are lined by alveolar epithelium with little to no mucus production.

So, the region with the highest concentration of goblet cells and mucous glands is the trachea and main bronchi.