Epithelital cells

From The School of Biomedical Sciences Wiki
Revision as of 08:56, 6 December 2017 by Nnjm2 (talk | contribs) (Added the references correctly, that is, I added them as explained in the lecture. Cleaned up the text. Reformatted the page.)
Jump to navigation Jump to search

Epithelial cells are that line the surfaces of parts of the body[1]. They are joined together in layers with one side exposed and the other is attached to a basement membrane[2].

Shapes

There are three main shapes of epithelial cells:

  1. Squamous- comes from the Latin word for scales and describes the appearance of the cells[3]. They can also be described as simple which refers to the fact that they are present in a single layer[4]. They are thin and flat which gives a short diffusion pathway for some exchange systems[5].
  2. Columnar- epithelial cells which are rectangular in shape and joined in rows creating this columnar appearance, making them harder to damage[6].
  3. Cuboidal- as the word suggests the cells are cuboid shapes, similar to the squamous epithelial cells except for the fact that they are not flat[7].

Where they are present in the body and their functions

Squamous epithelium are present in the lungs, blood vessels and kidneys[8]. In the lungs they form the structure of the alveoli, allowing carbon dioxide to be removed from the blood and oxygen to enter[8]. Their shape provides a short diffusion pathway which increases the efficiency of gas exchange[8]. In blood, they reduce friction and regulates blood pressure[8]. In the kidneys they allow a faster rate of filtration of the blood[8].

Columnar epithelium are present in bronchioles, intestines, stomach, endometrium, fallopian tubes and rectum[7]. They are present in these places order to help with secretion and absorption[7].

Cuboidal epithelium is present in the pancreas,bronchioles,kidney and various glands aiding in secretion, selective passage of materials and protection[7].

References

  1. Mosby's Medical Dictionary, the free dictionary by farlex, Epithelial cells, 2009, [cited 05/12/17]: Available from: https://medical-dictionary.thefreedictionary.com/epithelial+cell
  2. Mosby's Medical Dictionary, the free dictionary by farlex, Epithelial cells, 2009, [cited 05/12/17]: Available from: https://medical-dictionary.thefreedictionary.com/epithelial+cell
  3. Study.com, What is Simple Squamous Epithelium?, ND, [cited 5/12/17]: Available from: https://study.com/academy/lesson/what-is-simple-squamous-epithelium.html
  4. Study.com, What is Simple Squamous Epithelium?, ND, [cited 5/12/17]: Available from: https://study.com/academy/lesson/what-is-simple-squamous-epithelium.html
  5. Study.com, What is Simple Squamous Epithelium?, ND, [cited 5/12/17]: Available from: https://study.com/academy/lesson/what-is-simple-squamous-epithelium.html
  6. Biology dictionary, Simple Columnar Epithelium, ND, [cited 05/12/17]: Available from: https://biologydictionary.net/simple-columnar-epithelium/
  7. 7.0 7.1 7.2 7.3 Buzzle, Location, Structure, and Function of the Simple Cuboidal Epithelium, 2016, [cited 05/12/17], Available from: https://www.buzzle.com/articles/simple-cuboidal-epithelium-location-structure-and-function.html
  8. 8.0 8.1 8.2 8.3 8.4 Leann Mikesh, livestrong.com, What Are the Functions of Simple Squamous Epithelial Cells?, 2017, [cited 05/12/17]: Available from: https://www.livestrong.com/article/521075-supplements-that-affect-platelet-count/