Electron microscopic study on the epiglottic mucosa in human fetuses.
The differentiation of the epiglottic mucosa in human fetuses has so far been studied only by light microscopy. So, we studied the epiglottic mucosa in human fetuses (at gestational ages from the 7th to 21st week) by scanning (SEM) and transmission electron microscopies (TEM), and could disclose more detailed features of cellular differentiation of this mucosa. These results and the review of the literatures lead to the following conclusions: 1. Primary cilia appeared in the epiglottic mucosa around the 7th week of gestation. 2. Ciliated cells and the stratified squamous epithelium of the lingual surface appeared at the similar period as reported by others, but our study revealed that the squamous cells are immature even at the 21st week. 3. Glycogen granules in non-ciliated cells decreased paralleling the differentiation of the cells, suggesting that they provide a source of energy necessary for the cell differentiation.
Sakai
N
N
Department of Otorhinolaryngology, Hokkaido University School of Medicine, Sapporo, Japan.
Saito
J
J
Suenaga
T
T
Tanaka
K
K
Terayama
Y
Y
D002454:Cell Differentiation; D002923:Cilia; D004825:Epiglottis / Q000196:embryology* / Q000648:ultrastructure; D004848:Epithelium / Q000196:embryology; D006003:Glycogen / Q000032:analysis; D006801:Humans; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009092:Mucous Membrane / Q000196:embryology / Q000648:ultrastructure
D006003:Glycogen