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Simple squamous epithelium
Structure: This epithelium has only 1 layer and has thin flat cells.
Function: The main function of this type of tissue is facilitating the movement of viscera, active transport by pinocytosis, and secretion of biologically active molecules.
Location: the lining of vessels (endothelium) and serous lining of cavities: pericardium, pleura, peritoneum (mesothelium).
Simple cuboidal epithelium
Structure: This is a single layer of cube-shaped cells.
Function: Its main function is covering and secretion.
Location: kidney tubules, covering of the ovary, thyroid
Pseudostratified ciliated columnar epithelium
Structure: This tissue gives the appearance of looking like a stratified epithelium. However, it is only 1 layer with all cells adhering to the basal lamina. The reason for its stratified-looking appearance is the placement of nuclei at different levels.
Function: Its main functions are: protection, secretion, and cilia-mediated transport of particles trapped in mucus out of the air passages.
Location: Lining of trachea, bronchi, nasal cavity
Reference for descriptions: Mescher, A. L., & UchƓa, J. L. C. (2018). Junqueira's basic histology: Text and Atlas. McGraw-Hill Education.
04/28/22
[Simple Squamous Epithelium: Additional Information]
Mentioned above is that this type of epithelial tissue is found on the lining of vessels. This lining is thin as it is simple (1 layer) squamous epithelium. This is important so that quick exchange of substances can be regulated between the bloodstream and the surrounding tissues
In the lungs, the respiratory or gas-exchange surface consists of millions of alveol that is lined by a simple squamous epithelium. This epithelium is also very thin to facilitate the diffusion of gases like oxygen and CO2.
Sources of information:
https://histology.siu.edu/crr/rsguide.htm#:~:text=The%20respiratory%20or%20gas%2Dexchange,contain%20cuboidal%20surfactant%2Dsecreting%20cells.
https://www.cedars-sinai.org/programs/heart/clinical/womens-heart/conditions/endothelial-function-testing.html#:~:text=The%20endothelium%20is%20a%20thin,substance%20in%20the%20blood)%20adhesion.
[Simple Cuboidal Epithelium: Additional Information]
By lining the duct surface of glands and organs, the simple cuboidal epithelium can provide protection from abrasion, foreign particles, and excessive water loss. In the kidney tubules, the tissue helps in the absorption and transportation of filtered substances.
Source of information: https://bio.davidson.edu/people/kabernd/BerndCV/Lab/EpithelialInfoWeb/Simple%20Cuboidal%20Epithelium.html#:~:text=In%20the%20kidney%2C%20simple%20cuboidal,to%20have%20different%20surface%20proteins.
[Ciliated Pseudostratified Columnar Epithelium: Additional Information]
Found most heavily along the respiratory tract, pseudostratified ciliated columnar epithelium helps trap and transport particles brought in through the nasal passages and lungs.
These cells contain cilia on the apical surface. Cilia are motile. This means they move, beating in a synchronous rhythm to push fluid in a constant direction. In the trachea, cilia propel mucus and particles toward the pharynx and out of the airways.
Sources of information:
https://micro.magnet.fsu.edu/primer/anatomy/brightfieldgallery/pseudostratifiedciliasmall.html
http://medcell.med.yale.edu/histology/epithelia_lab/pseudostratified.php
04/28/22
[Additional Information: Histology Art Description]
The tissues in the drawing above are the following:
– Simple squamous epithelium
– SImple cuboidal epithelium
– Ciliated pseudostratified columnar epithelium
They were among the first photos of epithelial tissues that I found on this website. They each represent the types of epithelium in terms of shape (squamous, cuboid, columnar).