Which types of cells are responsible for producing mucus in the respiratory tract?

Goblet cells are specialized epithelial cells that produce and secrete mucus in the respiratory tract. This mucus plays a crucial role in trapping dust, pathogens, and other particles inhaled into the lungs, helping to protect the respiratory system and keep airways moist. The presence of goblet cells is particularly abundant in the lining of the airways, where they contribute significantly to the mucus layer.

Columnar cells also play a role in the respiratory system, but their primary function is not mucus production; they are involved in absorption and secretion. Squamous cells, on the other hand, are typically found in areas where exchange occurs, such as the alveoli, and do not produce mucus. Ciliated cells are important for moving mucus out of the airways but do not produce mucus themselves. Thus, the identifiable function of goblet cells in mucus production makes them the correct answer in specifying the cells responsible for this important respiratory function.