Pseudostratified columnar epithelium: Difference between revisions

| Caption = Illustration depicting Pseudostratified Ciliatedciliated Columnarcolumnar Epitheliumepithelium.

The term ''pseudostratified'' is derived from the appearance of this epithelium in the section which conveys the erroneous (''pseudo'' means almost or approaching) 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 [[basalbasement laminamembrane]]. The nuclei of these cells, however, are disposed at different levels, thus creating the illusion of cellular stratification. All Notcells allare ciliatednot of equal size and not all cells extend to the luminal/apical surface; such cells are capable of cell division providing replacements for cells lost or damaged.

Pseudostratified epithelia function in secretion or absorption. If a specimen looks stratified but has [[cilia]], then it is a pseudostratified ciliated epithelium, since stratified epithelia do not have cilia. Ciliated epithelia are more common and lines the [[trachea]], [[Bronchus|bronchi]]. Non-ciliated epithelia lines the larger ducts such as the ducts of [[Parotid gland|parotid glands]].

* '''Ciliated pseudostratified columnar epitheliaepithelium''' is the type of [[respiratory epithelium]] found in the linings of the [[trachea]] as well as the [[upper respiratory tract]], which allows filtering and humidification of incoming air.<ref>{{cite book |last1=Haschek |first1=Wanda |last2=Rousseaux |first2=Colin |title=Haschek and Rousseaux's handbook of toxicologic pathology |date=2012 |publisher=Academic Press |location=Amsterdam |isbn=9780124157590 |edition=Second}}</ref>

* '''Non-ciliated pseudostratified columnar epithelia''' are located in the [[prostate]]<ref>{{Citation|last=Ross, Michael H., auteur.|title=Histology : a text and atlas : with correlated cell and molecular biology|urldate=http://worldcat.org/oclc/108954070327 December 2018|publisher=Wolters Kluwer Health |isbn=9781496383426|oclc=1089540703|access-date=2019-09-11}}</ref> and membranous part of male [[vas deferens]].

* '''Pseudostratified columnar epithelia with [[stereocilia]]''' are located in the [[epididymis]]. Stereocilia of the epididymis are not cilia because their cytoskeleton is composed of actin filaments, not microtubules.<ref name="Hofer1996">{{cite journal|last1=Höfer|first1=D.|last2=Drenckhahn|first2=D.|title=Cytoskeletal differences between stereocilia of the human sperm passageway and microvilli/stereocilia in other locations|journal=Anatomical Record|date=1996|volume=245|issue=1|pages=57–64|doi=10.1002/(SICI)1097-0185(199605)245:1<57::AID-AR10>3.0.CO;2-8|pmid=8731041|doi-access=free}}</ref> They are structurally and molecularly more similar to microvilli than to true cilia.{{dubious|date=November 2020}}

* '''Pseudostratified columnar epithelia''' are found forming the straight, tubular glands of the [[endometrium]] in females.<ref>{{cite book|last1=Robbins, Cotran|title=Pathologic Basis of Disease|page=1080}}</ref> They are also found in the internal part of the [[ear]].{{citation needed|date=December 2024}}

File:2304 Pseudostratified Epithelium.jpg|Cross-section of pseudostratified columnar epithelium

File:2308 The Trachea-b.jpg|Second cross-section of pseudostratified columnar epithelium