Inside the nasal cavity, the surfaces of the middle and inferior conchae (turbinate bones) and their meatuses are lined by respiratory mucosa (= nasal mucosa ). The respiratory mucosa is made up of three tissue layers. Along the luminal surface is pseudostratified ciliated columnar epithelium. Interspersed among the columnar cells in the epithelium are many flask-shaped goblet cells. All of the densely packed cells in the epithelium are embedded in a basement membrane, which adheres to a thick layer of lamina propria. Dispersed throughout the loose connective tissue in the lamina propria is a rich supply of blood vessels and many seromucosal glands.
As inhaled air passes over the turbinate bones, it is prepared or conditioned to safely pass deeper into the respiratory system. The heat radiated from the blood vessels in the lamina propria warms the air to near body temperature. Simultaneously, the watery mucus secreted from the globet cells and seromucosal glands humidifies (= adds moisture) the air and traps foreign particles. Wave-like beating of the cilia along the free surfaces of the columnar epithelial cells moves the debris-filled mucus to the throat, where it is usually swallowed.
