trachea

This is a transverse section through part of the wall of the trachea, showing the ciliated and mucus-secreting lining of the airway and a reinforcing ring of cartilage.

Transverse section at medium power showing the respiratory epithelium (to the right) and cartilage reinforcing the wall of the trachea. The region marked by the rectangle is shown in the next picture.	High power view of the respiratory epithelium and submucous layer.	Respiratory epithelium - ciliated and mucus-secreting.