Table of contents:
- What is epithelial tissue?
- Where is the epithelial tissue located on the body?
- The function and role of epithelial tissue in the body
- What are the types of epithelial tissue?
- 1. The flat epithelium layer (simple squamous epithelium)
- 2.Cube epithelium layer (simple cuboidal epithelium)
- 3.Cylindrical epithelium layer (simple columnar epithelium)
- 4. Flat epithelium layered (stratified squamous epithelium)
- 5. The epithelium of the layered cubes (stratified cuboidal epithelium)
- 6.Cylindrical layered epithelium (strarified columnar epithelium)
- 7.Pseudostrative columnar epithelium (pseudostrativeied columnar epithelium)
- 8.Transitional epithelium (transitional epithelium)
Did you know that the human body is made up of many different tissues? Yes, apart from being supported by various cells, bones and organs, the human body also consists of several tissues. One of them is epithelial tissue. Are you actually curious about the role of this tissue in the human body? Check out the full review below.
What is epithelial tissue?
Tissue is a collection of cells that helps build various organs and other parts of the body. Like arms, hands, to feet. When observed carefully through a microscope, the tissues that make up the human body have a neat and orderly structure according to their function.
This function then differentiates the tissue according to its location in the body. That is why the human body is composed of four main types of tissue; includes muscle tissue, connective tissue, nerve tissue, and epithelial tissue.
Epithelial tissue is one of the tissues with a large surface area with very tight cells. This tissue serves to coat or cover the surface of the body and make up the outermost parts of the organs.
In other words, this one body tissue acts as a "gate" that protects the body from direct exposure to the outside world. Therefore, all substances that try to enter the body must go through the epithelial tissue first.
Where is the epithelial tissue located on the body?
In view of their task which is directly dealing with the outside world, the epithelial tissue in the body is usually located in the skin, respiratory tract, digestive tract, urinary tract, and reproductive tract.
The structure of this body's protective tissue tends to be thick because it is composed of several layers of thick keratinized cells to provide strength and resistance to the mechanism. Take, for example, the skin as the body's most extensive organ. The skin turns out to be covered with epithelial cells with thick keratin content to prevent the body from losing too much water or other important substances.
Likewise with the esophagus (esophagus) which is part of the digestive tract. During the course of its duties, the esophagus is always in direct contact with a variety of foods and beverages that have different textures, compositions and pH levels.
Hence, the esophagus is also protected by epithelial tissue. It's just that, the structure of the epithelial tissue on the inside of the body tends to be thinner or not as thick as the tissue in the skin. Not only in the esophagus, but also the thin epithelium also protects the stomach, small intestine, large intestine, fallopian tubes in the reproductive tract, and bronchioles in the lungs.
Some of these parts are protected by a thin epithelium covered with cilia or microvilli to make their job easier. Meanwhile, the bladder, ureters and urethra are protected by transitional epithelium which aims to facilitate the stretching process and expand the capacity of these organs.
The function and role of epithelial tissue in the body
As mentioned earlier, epithelial tissue in the body is intended for several functions including:
- As protection (protection) of the tissue underneath from exposure to the outside world, such as radiation, harmful compounds, and so on.
- Helps smooth the process of absorption of substances in the digestive tract.
- Helps regulation and excretion of chemicals in the body.
- Helping the release of hormones, enzymes, drying, and other end products produced by the body.
- As a detection of sensations that are felt by the skin.
What are the types of epithelial tissue?
Epithelial tissue is classified into 8 types according to cell shape, number of cell layers, and the type of cell itself. Six of them were identified based on the number of cells and their shape, while the remaining two were differentiated based on the type of cells in them.
There are 3 groups of cell shapes in this network, namely flat and flat (squamous), square (cuboidal), or tall and wide (columnar) rectangles. Likewise, the number of cells in the tissue can be classified as simple epithelium and stratified epithelium.
Well, here are the various types of epithelium that are scattered in the body:
1. The flat epithelium layer (simple squamous epithelium)
The flat or flattened epithelium serves to filter (filtrate) substances that will enter the organs, as well as produce lubricants to smooth the organ's work. This epithelium can be found in the kidneys, the lining of the heart, blood vessels, lymphatic vessels, and the air sacs of the lungs (alveoli).
2.Cube epithelium layer (simple cuboidal epithelium)
The cube epithelium in a layer is responsible for facilitating the body's organs in carrying out the secretion and absorption process. The epithelium is located in the kidneys, ovaries, and various glands in the body.
3.Cylindrical epithelium layer (simple columnar epithelium)
Similar to the layer cubic epithelium, the layer cylindrical epithelium also facilitates the work of the organs in the secretion of mucus and enzymes, as well as the absorption of certain substances. But the difference is, this one epithelium is equipped with the presence of mucus and tiny cilia like hair.
This epithelium is found in the digestive tract, lung bronchi, uterus, and several other glands.
4. Flat epithelium layered (stratified squamous epithelium)
The epithelium is flat or layered flat plays a role in protecting the underlying tissue. There are two types of layered flat epithelium, the first is located under the skin layer with a harder structure because it contains keratin protein in it.
While the second without keratin protein (nonkeratinized) is located in the mouth, esophagus, urethra, vagina, and anus.
5. The epithelium of the layered cubes (stratified cuboidal epithelium)
The layered cube epithelium acts as a protector for the tissues, glands, and cells underneath. It is located around the breast glands, salivary glands, and sweat glands.
6.Cylindrical layered epithelium (strarified columnar epithelium)
The layered cylindrical epithelium is responsible for smoothing the secretion process and organ protection. This epithelium is usually found only in the male body. Precisely in the urethra and associated with certain glands.
7.Pseudostrative columnar epithelium (pseudostrativeied columnar epithelium)
The pseudostrative columnar epithelium is a single cell layer with different heights. Its job is to smooth the process of secretion and movement of mucus in the organs. This epithelium is commonly found in the throat, upper respiratory tract, spermatic tract, and other glands.
Pseudostrative columnar is a single cell layer of variable height. This tissue allows the secretion and movement of mucus. It is located in the throat and upper respiratory tract, sperm ducts, and glands.
8.Transitional epithelium (transitional epithelium)
The transitional epithelium is described as a tissue consisting of more than one layer of cells, with a combination arrangement of cubes and flats. It is located in the urinary system, especially the bladder, which aims to allow stretching or enlargement of the organs while collecting urine.
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