Bird, trachea (LM, Medium)

Structure List Mucous Epithelium Mucous gland Cartilage

A bird's trachea is similar to that of the mammal. However, there are a few important differences. The hyaline cartilage rings are complete. The diameters of these rings vary so that a narrow part of one ring fits into the wide part of an adjacent ring. Thus, as a result, an overlapping pattern of tracheal rings is achieved. Ossification of the tracheal rings occurs in some species. Note that the avian trachea is also lined by a CILIATED, PSEUDOSTRATIFIED COLUMNAR EPITHELIUM that is invaginated in many areas to form simplified glands.