While mentioning about epithelial cells and endothelial cells, it is not very easy to distinguish them clearly. Here are some features of epithelial cells and endothelial cells that can be used for further understand about this two cells.
Endothelial cells cover the inner surface of the blood vessel, while the epithelial cells cover the inner surface of the internal organs and the outer surface of the human body. If a large number of epithelial cells was found in the urine, it indicates urinary tract infection. The endothelial cells and epithelial cells which can constitute the tissue both are derived from the epithelium, but they differ in the position, structure, function. In addition, both of them constitute an interface between the inner and outer environments. Endothelial cells are located within the “internal” of the body, such as the interior of the blood vessel, and the epithelial cells are usually described as covering the “outside” of the body, such as the outer layer of the skin (epidermis).
1.The differences in the position
Endothelial cells constitute endothelium, which covers the inner surface of the blood vessel. In simple terms, the cells are close to the vessel wall. So the entire internal circulation of the circulatory system is covered by endothelial cells. These cells form the interface between the vessel wall and the blood. The ventricle tissue which is close to the inner surface is a layer of single cells thick tissue.
Epithelial cells that form epithelial tissue not only cover the outer surface of the body, but also cover the outer surface of all the internal organs of the body. For example, the outermost epidermis of the skin is epithelial cells. So the surface of the skin covered by epithelial cells, it provides a protection for the body. Epithelial cells also cover the surface of internal organs, such as the liver, stomach, intestine, lung, urethra, bladder and so on. In other words, epithelial cells cover the surface of the body and internal tissue.
2.The differences in the function
Endothelial cells covering the blood vessel wall can regulate blood flow in blood vessels, which can release NO – the vasodilator factor that promotes blood circulation and helps to control blood pressure. Endothelial cells can also secrete a variety of proteins leading to blood disorders, but involving Hemostatic function. Such as the role in Glomerular internal is to filter the blood.
The epithelial cells that make up the skin protect the subcutaneous tissue from damage, bacterial ingress, dangerous chemicals, and avoid excessive loss of moisture. Epithelial cells of skin will secrete sweat to regulate body temperature if necessary. The epithelial cells that cover the pancreas secrete enzymes to promote digestion. In addition, epithelial cells on the surface of the small intestine absorb nutrients from digestive food. The epithelial cells on the surface of the respiratory tract form mucosa, which can secrete mucus to prevent inhalation of bacteria from entering the lungs with the virus. Skin, nose, tongue, eyes and other organs exposed to nerve endings on the secretion of specialized epithelial cells, they can identify the sensory stimulation. In short, the main function of epithelial cells involves the secretion, absorption, protection.
3.The differences in the structure
Endothelial cells are monolayer structures, and water molecules with oxygen molecules are easily passed through endothelial cells into the tissue surrounding the endothelial cells. In addition, endothelial cells lack packed endothelial morphology, the gap between cells contribute to the passage of liquid and material diffusion.
Epithelial cells have a variety of structures to protect the body from external environmental damage. Epithelial cells are tight integration to each other like the bricks, there is a little gap between the cells.
A.Endothelial cells are supported by intermediate filaments to constitute the cell structure, it contains vimentin filaments, while the structure of epithelial cells is supported by keratin filaments.
B. The surface of endothelial cells is non-thrombogenic soft surface, blood will not solidify in the normal blood circulation process. Epithelial tissue in different types of epithelial cells presents irregular papillary projections.
C. The endothelium is one of the epitheliums, which is distributed on the inner surface of the blood vessel. In the lumen, the endothelium constitutes the interface of the circulatory system or the lymphatic system and the rest of the blood vessel.
All the above is the information about the differences between endothelial cells and epithelial cells.