Distribution of mucus producing elements in the respiratory tract. Differences between upper and lower airway.

Based on quantitative studies of glands and goblet cells in the nose, sinuses, trachea and bronchi a short survey on distribution of mucus producing elements is presented and the density of glands and goblet cells compared between upper and lower respiratory pathways. The gland density is highest in the nose 8.3 glands/mm2 low in the trachea, bronchi and nasopharynx, but the gland mass per gland is 3-4 times larger in these regions than in the nose. In the paranasal sinuses the gland density is extremely low and the mucus producing capacity almost negligible. In the nose the goblet cell density is highest in the inferior turbinate, lowest in nasal septum.