Today we will focus on defining what epithelial tissue is. For all those readers interested in learning more about the subject. An attempt will be made to cover all the information pertinent to the treated objective.
It is known as epithelial tissue to those tissues that are on the accumulations or underlying groups of connective tissues. It is worth mentioning that epithelial tissue originates from one or several layers of cells. Which are intertwined with each other. This union of cells allows it to cover every exposed surface of the living organism. What enables the formation of the internal coverage of the cavities.
As well as allowing the formation of hollow organs, and body conduits. In turn, the epithelial tissue stimulates the production of mucous membranes and glands. An innate characteristic of these tissues is that each and every cell exists without exception in the tissue. By uniting with the others, they form a series of layers or sheets that are identified by an extracellular matrix.
Said matrix is limited and positioned below the epithelial cells. It is also important to mention that they are not vascularized, so the way in which they can be sustained is through diffusion. It is known that there will always be connective tissue under each epithelium. We must also know that this type of tissue is the only one that comes from the blastodermal layers.
The formation of the term «epithelium». It is composed of the suffix “epi” which means “on” and the base “telio”. What does “cumulus” mean? It is evident that the name is given to the fact that this type of tissue is located on accumulations of connective tissue. As explained above.
What is Epithelium? Let’s know its definition.
We previously learned what the etymological origin of the word “epithelium” was. The concepts of epi and telium came to scientific Latin as “epithelium”. From the beginning, the idea of this concept referred to the fact that it is part of the mammary papilla. Of course, with the passing of time, the concept or notion of epithelium began to be used to refer to the tissue made up of the cells in charge of maintaining direct touch.
The main function of epithelial tissue is to cover the surface of the body, cavities and ducts. So it is valid to say that the epithelial tissue (or epithelium, as you like to call it). It is generated by unification of the cell layers. Which, as we have already mentioned, cover the free spaces of the living organism.
In the mucous membranes, organs and glands, epithelial tissue is present. It gives rise to what we know as the sense organs. This effect is called “sensory epithelium”. While the epithelial tissue that structures the entire secret sector of the glands. They are called secretory epithelium or glandular epithelium.
The epithelium containing cells with melanin. It is named as pigment epithelium. And finally in this chain of identification of each epithelium, we have the epithelium that makes up the outer layer of the epidermis and the mucosa. This is given the name of lining epithelium.
The Classification of Epithelial Tissue.
It becomes possible to identify a variety of epithelial tissue classifications, depending on the type of criteria that it is decided to take into account. We will see later some of the most important classifications. We will start this list with those that are made based on their function.
based on its function.
- The sensory epithelium: The way in which this type of tissues are classified is because they are those that lie in the parts called sensory cells.
- The squamous epithelium: Another way in which this classification of epithelia is called is as “lining epithelium”. And they consist of all those that line the cavities and ducts of the organism inside. Or the skin on the outside. The cells of these tissues are in the form of layers or sheets.
- The respiratory epithelium: It does not have a major complication, since its very name explains it by itself. It is the one that is associated with the respiratory tract.
- The glandular epithelium: The main function of this type of tissue is to develop the formation of glands. Since they have a great capacity for the generation of substances and mucosa.
- The intestinal epithelium: Unlike those previously mentioned, these tissues have independent cells. So they acquire different sensory functions.
- The prismatic epithelium: This type of tissue is also known as cylindrical tissue and the cells that these have are res columns. This name is given to it because its height considerably exceeds its width. Which forces its nucleus to be ovoid.
- The cuboidal epithelium: Unlike the previous epithelium, which is made up of cylindrical cells by its cells. The cuboidal epithelium is made up of cuboidal cells. Which means that they have the same proportion in both height and width. And the nucleus they have is spherical.
- The squamous epithelium: And to finish off this list. We have the squamous epithelium, which is also called the squamous epithelium. It is made up of flat cells. Which case is reversed to of the prismatic epithelia. Since its width is much greater than its height. What makes its nucleus have a flattened shape.
Based on the number of layers.
In this classification criterion we are going to find those epithelia that are defined by the number of cell layers that make it up. For this list only three will be taken into account.
- Pseudostratified epithelium: These are tissues that are made up of a single layer of cells. Although they do not have a specific order.
- Simple epithelium: They are those that have a single layer of cells. This type of epithelia is also given the name “monostratified”.
- Stratified epithelium: This section is where those who do have more than one layer of cells come in. which are ordered. It is worth mentioning that because they are several layers in them, various lines of nuclei are formed.
In this way we conclude with the writing of this post. We hope that all the information provided throughout this publication has been very useful to you. If you have any complaints with the information presented, do not forget to comment and notify us in the comments.