(Redirected from Pseudostratified columnar)
A 'pseudostratified epithelium' is a type of
epithelium that, though comprising only a single layer of
cells, has its
cell nuclei positioned in a manner suggestive of
stratified epithelia. As it rarely occurs as
squamous or
cuboidal epithelia, it is usually considered synonymous with the term 'pseudostratified columnar epithelium'.
The term ''pseudostratified'' is derived from the appearance of this epithelium in section which conveys the erroneous (pseudo means false) impression that there is more than one layer of cells, when in fact this is a true simple epithelium since all the cells rest on the basement membrane. The nuclei of these cells, however, are disposed at different levels, thus creating the illusion of cellular stratification. Not all ciliated cells extend to the luminal surface; such cells are capable of cell division providing replacements for cells lost or damaged.
Examples
★ 'Ciliated pseudostratified columnar epithelia' are found in the lines of the
trachea as well as the
upper respiratory tract.
★ 'Non-ciliated pseudostratified columnar epithelia' are located in the lining of the male
urethra.
If a specimen looks stratified but has
cilia, then it is a pseudostratified ciliated epithelium, since stratified epithelia do not have cilia.
Gallery
External links
★
★
Diagram at uoguelph.ca
★
★ "Trachea"
★
Slide at ohio-state.edu