"Respiratory" (i.e., ciliated pseudostratified columnar) epithelium is found in all of the following structures, EXCEPT:

Respiratory epithelium is found in the nasal cavities, in the trachea and in both the extrapulmonary and intrapulmonary bronchi. It is not found in alveoli, where it is necessary to minimize diffusion distances by the use of simple squamous epithelia. Ref: Mescher A.L. (2010). Chapter 4. Epithelial Tissue. In A.L. Mescher (Ed),Junqueira's Basic Histology: Text & Atlas, 12e.