Correlated Light Microscopic and Transmission and Scanning Electron Microscopic Studies of the Laryngotracheal Epithelium in Salamanders, <italic>Hynobius nebulosus</italic>

Abstract

The laryngotracheal epithelium of adult and young adult salamanders, Hynobius nebulosus, was studied with light microscopy and transmission and scanning electron microscopy (SEM). Cartilago lateralis was differentiated into Cart, arytenoidea and Cart, cricotrachealis, but not Cart, trachealis. Therefore, the laryngotracheal cavity was divided into an arytenoid portion (A) and a cricotracheal one (C). A and C were covered with pseudostratifled, eolumrtal and cuboidal or flat epithelium, respectively. The epithelium consisted of ciliated and non-ciliated cells. The latter were subdivided into mucous cells including goblet cells, and basal cells. The mucous cells were classified into ordinary and mitochondria-rich types. The latter were characterized by the presence of numerous mitochondria, scanty RER and mucous granules, and filament bundles in the cytoplasm. In SEM this type has abundant microfoMs on the apical surface. In the caudal area of C ordinary type mucous cells wrapped capillary walls and were transformed into respiratory epithelium.