Epithelial cells

Single-layer, single-row epithelial tissues may include epithelial cells of various shapes. So, they can be prismatic, cubic, flat.

Endothelium and mesothelium represent a single-layered flat tissue in the body.

Mesothelium covered with serous membranes (peritoneum, pleura sheets, pericardial bag). Epithelial cells of mesothelium have uneven edges and polygonal shape. Through the mesothelium, suction and discharge of serous fluid is carried out. Its smooth surface provides easy sliding of internal organs. Mesothelium also prevents the occurrence of adhesions between the abdominal or thoracic organs, the development of which can occur with its complete violation.

Endothelium lined with lymphatic and blood vessels. It is represented by flat epithelial cells (endotheliocytes). They form a single-layer formation on the basal membrane. Endothelium is located in vessels on the border with blood or lymph and takes part in the exchange of gases and substances between these vessels and other tissues. Its damage is caused by a change in the vascular blood flow and formation of a blood clot in the lumen.

A part of the tubule of the kidneys is lined with a single-layered cubic epithelium. It provides the back absorption (reabsorption) of some substances into the blood from the primary urine.

The tissue, including prismatic epithelial cells, is characteristic of the average digestive department. They are lined with internal gastric and intestinal surface, some hepatic ducts and pancreas, gall bladder. The cells of the epithelium are connected by desmosomes, slotted communication connections, by the type of the lock, by dense closing connections. Due to this, the contents of the intestinal and gastric cavities do not penetrate into the tissue slit.

The airways are lined with multilayer epithelium, which are ciliated and contain various forms and perform various cell functions.

The cornea of the eye from the outside, the esophagus and the oral cavity are covered with a multilayer flat tissue. This epithelium includes three layers: flat (surface), basal and intermediate (prickly).

A multilayered flat keratinized tissue is covered with a dermal surface. Thus, skin epidermis is formed. Here the process of keratinization is carried out, which is associated with the differentiation of epithelial cells. The epidermis includes several layers. This includes a prickly, basal, horny, granular and shiny cell layer. Particularly expressed are the last three layers in the skin of the soles and palms.

Transitional epithelium (multilayered) is typical for urinary organs (renal pelvis, bladder, ureter). There are several layers: surface, intermediate, basal layer. Epithelial cells in the urine (urinary sediment) are almost always found. The norm is their content no more than ten in the field of view. The indicator is detected using a general urine test.

The integumentary tissue occupies a "borderline" position. This tissue is under the constant influence of the external environment, so its cells wear out and die relatively quickly. Recovery is due to stem cells. They have the ability to divide and retain it throughout the life of the body.

Epithelial tissue is fairly innervated. It includes receptors (nerve endings that are sensitive) in large numbers.

Epithelium lining the cervix and vagina. Its increase depends on the increase in the content of female hormones in the body. Epithelial cells in the smear from the vagina are normally present. The number of them varies depending on the hormonal drugs used, the phase of the cycle of menstruation. The absence of cells can indicate tissue atrophy, a lack of estrogen or an excess of male hormones.