Pseudostratified columnar epithelium

Pseudostratified Columnar Epithelium

File:Pseudostratified columnar epithelium.jpg

Pseudostratified columnar epithelium

The Pseudostratified columnar 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 is not truly stratified, it is referred to as "pseudostratified".

Structure

Pseudostratified columnar epithelium is a type of tissue that appears stratified but is not. All of the cells are attached to the basement membrane in a single layer, but not all reach the apical surface. The nuclei are seen at different levels, giving the appearance of being multi-layered, hence the term "pseudostratified".

Function

The primary function of pseudostratified epithelia is secretion and movement of mucus. They are found lining the trachea and upper respiratory tract where the mucus helps to trap dust and microorganisms and move them out of the airways.

Types

There are two types of pseudostratified columnar epithelium:

1. Pseudostratified Ciliated Columnar Epithelium: This type contains cells with cilia at their apical surfaces. These are found in the upper respiratory tract, the fallopian tubes, and a few other locations.
2. Pseudostratified Non-ciliated Columnar Epithelium: This type does not have cilia. It is much less common, found only in a few locations in the body, such as the male urethra.

See Also

• Epithelium
• Stratified epithelium
• Simple columnar epithelium
• Ciliated columnar epithelium