Epithelial vs Endothelial Cells
Epithelial and endothelial cells are far too different types of cells forming different types of tissues in animals. The location, form, and function are different in these two types of tissues. However, it would be fair enough for an average person to commit some errors in understanding due to being unfamiliar with these terms. Therefore, some simplified and summarized information, as in this article, would be ideal to understand the characteristics of these important cell types. In addition, the presented differences between the characteristics of these two types of cells would make it more sensible to the reader.
Epithelial cells form the epithelium, which usually lines the surfaces of the body including the most widely spread and the largest organ of the body, skin. Epithelium is one of the four basic types of tissues; others are muscle tissue, nervous tissue, and connective tissue. In addition to the lining of the skin, the epithelial cells line many glands and cavities of the body. The epithelium is formed by different layers of epithelial cells, which are packed tightly in each layer without leaving any space between cells. These densely packed cells resemble the bricks of a wall, as there are almost no intercellular spaces with tight junctions and desmosomes. Depending on the shape and structure of these cells, there are few types of epithelial tissues known as Simple squamous, Simple cuboidal, Simple columnar, Stratified squamous, Stratified cuboidal, Pseudo stratified columnar, and Transitional epithelia. The epithelium is an avascular tissue, which means there are no vessels to carry blood. Therefore, the nourishing of the epithelial cells takes place through diffusion of nutrients from the closest underlying connective tissues. The purposes of the presence of epithelium or functions of the tissue are protection, secretion, selective absorption, transcellular transportation, and detection of senses. Therefore, the importance of these cells is immense.
Endothelial cells are a lining layer of cells or tissue (endothelium), especially the interior of the blood vessels. In fact, the endothelium lines the entire circulatory system including the one and only heart and all types of blood vessels. Endothelial cells form the interface between the lumen and wall of the vessel. The endothelium has an epithelial origin, and there are vimentin filaments, and it provides a non thrombogenic surface for the blood clotting. The endothelium or the endothelial cells as a unit mainly form a selective barrier for the contents (nutrients) in the lumen and the surrounding organs or tissues. In addition, the formation of new blood vessels, blood clotting, control of blood pressure, and many more functions are either assisted or performed by the endothelial cells.
What is the difference between Epithelial Cell and Endothelial Cell?
• Both tissues are of epithelial origins, but the endothelial cells have vimetntin, but epithelial cells have keratin filaments.
• By the sound of the terms, endothelium lines the innermost layer of the circulatory system while epithelium usually lines the outer surfaces of the body. Epithelium linings usually expose to the outside or exterior of the body (e.g. Skin, Intestine, Urinary bladder, Urethra, and many other organs). However, the endothelial layers are never exposed to the exterior as they line the innermost layer of the circulatory system, which is a closed system.
• Depending on the type of tissue, the number of layers varies for the epithelium, but endothelial cells always present as a single layered tissue called epithelium.
• Endothelium provides a non-thrombogenic surface but not the epithelial layers.