Pseudostratified columnar epithelium

A specialized type of epithelial tissue that appears to be layered due to differing cell heights.

Pseudostratified columnar epithelium is a type of epithelial tissue characterized by its unique structure where all cells are attached to the basement membrane but appear to be arranged in layers due to varying cell heights. This gives the impression of stratification, hence the name 'pseudostratified', meaning false layers. The tissue is primarily composed of column-like cells, which can be either ciliated or non-ciliated, contributing to its specific functions in the body.

Terminologia Anatomica

epithelium pseudostratificatum columnare

System

Respiratory system

Function

The primary function of pseudostratified columnar epithelium is to facilitate the movement of mucus and foreign particles through ciliary action, particularly in the respiratory system. The ciliated variety lines the trachea and bronchi, where it traps particulate matter and pathogens within mucus produced by goblet cells. The coordinated movement of cilia helps propel this mucus upwards towards the throat, where it can be swallowed or expelled. In addition to its transport function, this type of epithelium plays a role in secretion and absorption, accommodating various processes necessary for maintaining the integrity of the respiratory epithelium and protecting underlying tissues.

Location

Pseudostratified columnar epithelium is predominantly located in the respiratory tract, particularly lining the trachea, bronchi, and nasal cavity. In these regions, it forms a protective barrier that facilitates the efficient movement of mucus and debris out of the airways. Additionally, it can be found in parts of the male reproductive system, specifically within the epididymis, where it aids in the maturation of sperm by providing support and secretion. The strategic placement of this epithelium is crucial for its role in protection, secretion, and the maintenance of airflow within the respiratory passageways.

Did You Know?

Even though it appears layered, pseudostratified columnar epithelium is made up of a single layer of cells that are all in contact with the basement membrane.
The cilia on this epithelium can move in a coordinated wave-like motion, enhancing the effectiveness of mucus clearance in the respiratory system.
Goblet cells, which are often found interspersed within this type of epithelium, are responsible for secreting mucus that traps dust and pathogens.