When people talk about this kind of fabric is remembered primarily leather, while epithelial tissue - it is, in principle, a kind of "border guard".She separated from each other organs, and it is contained in the composition of the mucous membranes.Heterogeneity of epithelial tissue, structure and function is linked in a special way for each type of fabric.About what kinds of speech?Read more.
characteristic common feature of all types - cells that are in close contact with each other, often arranged in layers, due to the barrier function of epithelial tissue.Also, all types of epithelial tissue in common is that of the neighboring structures are always separated by connective tissue - a formation called the basement membrane.
Generally epithelium is simple (single layer) and the laminate (several).Accordingly, the structure of epithelial tissue can be very different.
simple epithelium may be slightly flattened in shape.This type is called squamous cell.It lines the lungs, blood vessels, heart cavities.Also, these cells are in the upper layers of the skin and oral mucosa.
not difficult to guess the shape of a cubic epithelium cells.Such cells are found in the glands, glands and ducts of the renal tubules.In addition, they constitute the germinal epithelium in the ovaries of women's and men's testicles.
epithelium is prismatic simple and layered.The cells have the shape of elongated bars.Nuclei in these cells are "hidden" closer to the basal lamina and away from the surface.Well, in the stomach, whose face they line, it is very efficient - too aggressive there Wednesday.Some of these cells are part of the sensory organs - smell, taste, hearing.
ciliated columnar epithelium is a special form of growths that rapid undulations are able to promote something that is close to them.They "live" in the nose and ... in the fallopian tubes in women, allowing them to promote egg to the uterus.
glandular epithelium called prismatic comprising secreting cells.Sometimes cells secreting more than columnar.Where are the cells that can create a secret?This epithelial tissue cells that have passed the path of specialization.And the "experts" they can be very different.Engaged in the production of enzymes, hormones, milk, mucus, sweat, saliva and wax.Of course, all these substances are unable to produce unicellular glands glands this case consisting of many epithelial cells.A single cell called goblet cells.Initially they were named enterocytes because most of these cells in the small intestine.But then it turned out that they are present in the conjunctiva of the eyes and the respiratory system, and in the ducts of the glands.
Where high friction and the risk of injury, the body builds a complex epithelium - the same one that always consists of several layers.It is a skin and mucous membrane of the mouth.On the skin surface cells arranged in which much of the protein keratin, keratin mouth few cells, so to touch the skin and oral mucosa are significantly different.
epithelial tissue function is very different.The list below is not completely full.
protective function .Epithelium prevents mechanical damage, chemical burns, posing a barrier against infection and protects the cells from the underlying water loss.
function sensations : specialized cells of epithelial tissue form organs sensations.
secretory function : described in detail in the section of the glandular epithelium.
absorptive : the small intestine through the epithelium of the absorption of nutrients is carried out.
Excretion : sweat glands secrete waste products, as epithelium kidney is able to engage in filtering, and in the re-absorption too.
Diffusion : through a thin epithelium in the respiratory system of the body and from the penetrating gases.
cleansing function : airway epithelium cleans the air from dust.
Reducing friction : epithelium of the vessels reduces the friction between the vessel wall and blood cells.
As you can see, a lot of functions, because many species.For more information, you look for good books on histology.
