Clear epithelium covers the mucous membrane. Single-layer multi-row fixed epithelium

Morphofunctional characteristic of single layer

epitheliyev

Varieties and their distribution in the body;

features of the structure

Nomenclature

Polarity

The concepts of "horizontal isomorphism" and

"Horizontal anisomorphism"

Cambia Localization

Regeneration vector orientation

I. Single-layer epithelium.

1. Single-layer single-row epithelium.

a) single-layer flat;

b) single-layer cubic;

c) single-layer cylindrical (prismatic):

Single-layer Prismatic Cam

Single-layer prismary iron

Single-layer pricious flicker

Morphofunctional classification (applied more often):

I. Single-layer epithelium. In one-layer epithelium, all cells without exception are directly related, (in contact) with a basal membrane.

1. Single-layer single-row epithelium. In a single-layer single-row epithelium, all cells are in contact with the basal membrane; Have the same height, so the kernels are located at one level.

a) single-layer flat; consists of one layer of sharply flattened polygonal shape cells (polygonal); The base (width) of cells is greater than height (thickness); There are few in the cells of organoids, there are Mi-Tucheondria, single microwaves, pinocytous bubbles are visible in the cytoplasm. Single-layer flat epithelium widespread serous covers (peritoneum, pleura, oolely bag).

b) single-layer cubic; On the slice of the cells diameter (width)

equal to height. It is found in the output ducts of the exocrine glands, in rally kidney channels.

c) Single-layer cylindrical (prismatic): on a slice of cell width less than height. Depending on the characteristics of the structure and the function distinguish:

Single-layer Prismatic Cammed: The intestines lines, on the Api-cool cell surfaces there are a large number of microvones; Specialized for suction.

Single-layer Prismatic Irony: It is in the stomach, in the cervical cervical channel, specialized for continuous mucus production

Single-layer Prismatic Cleaning: Wallowed Outcasting Pipes; on the apicial surface epithelocytes are cilia

The regeneration of the single-layer single-row epithelium occurs due to stem (cambial) cells, evenly scattered among other differentiated cells.

2. Single-layer multi-row fixed epithelium - all cells are in contact with the basal membrane, but have different heights and therefore the cores are located at different levels, i.e. In several rows. Waves the air paths.

The composition of this epithelium distinguishes the varieties of cells:

Short and long inserted cells (unoccalued and stem stem cells; provide regeneration);

Wine-shaped cells - have a globe shape, they are poorly perceived by the beautiful (in the preparation - white), the mucus produce;

Cells, on the apical surface there are flickering reschs.

Function: Cleaning and moisturizing undergoing air.

3 Question ...

Single-layer prismatic epithelium characteristic For the middle department of the digestive system. It sweels the inner surface of the stomach, thin and colon, gallbladder, a number of liver and pancreas ducts. Epithelial cells are connected with each other with the help of despams, slit communication compounds, by type of lock, dense closing compounds. Thanks to the last in the intercellular epithelium slot, the contents of the cavity of the stomach, intestine and other hollow organs can not penetrate.

In the stomach in one-layer Prismatic epitheliums All cells are ferrous, producing mucus, which protects the wall of the stomach from the coarse effect of chumps of food and digesting the actions of the gastric juice. A smaller part of the epithelium cells is a cambial epithelialocytes capable of sharing and differentiate into ferruginous epithelial cells. Due to these cells, every 5 days is full update of the stomach epithelium - i.e. His physiological regeneration.

In the small intestine epithelium Single-layer Prismatic Care, actively involved in digestion. He covers the surface of the Village surface and, mostly, consists of carbon epithelocytes, among which the ferrous glazing cells are located. The end of the epithelocytes is formed by numerous microwaves covered with glycocalix. In it and the membrane of the microorusok are enzyme ensembles, which carry membrane digestion - splitting (hydrolysis) of food substances to final products and suction of them (transport through the membrane and cytoplasm of epithelocytes) into the blood and lymphatic capillaries of the subjectable tissue.

4 Question ...

Multi-row flicker prismatic epithelium.

This is a single-layer epithelium. It develops from a precrowdal plate. This type of epithelium sweeps the mucous membrane of the air paths. All epithelium cells come into contact with the basal membrane, but the height of the cells is different, the kernels are located at different levels. Created a multi-row effect. The focusing epithelium includes the following types of cells:

1. Prismatic Cilic Cells. On the apical surface of these cells there are cilia that make flickering. Cilia have a height of 5 - 10 nm. Organelles and kernel are in the basal part.

2. Balo-shaped cells. These cells have a prismatic form. They contain all general-purpose organelles, smooth EPS, a Golgi complex. As the secret accumulation is accumulated, the cells are expanding and acquired a glassworm form. Organelles and kernels become "attached" to the ground. This cell is an exocrine iron.

3. Basal cells. This type of cells has the base of the triangular shape, the apical end of the cell does not reach the surface of the mucous. The kernels have a rounded shape. The main function of these cells is division.

4. Insert cells. These cells are located higher than basal, but also do not reach the surface of the mucous. They are partially determined, therefore. They can be converted either into widow-shaped or cilia cells.

5. Endocrine cells. In these cells contain secretory inclusions. Endocrine cells secrete norepinerenaline and serotonin, which control the condition of smooth muscle cells of the air pathways. G is a single-layer prismatic multi-row epithelium: on the right - the cut, in the center - the usual, on the left - the seating (flicker)

5 question ...

In one-layer epithelium Physiological regeneration is due to the mitotic division of young cells located in special deepening crypts or scattered between the mature cells of the epithelial layer.

In case of damage to the epithelial layer, reparative regeneration takes place. In case of damage to the single-layer single-row flat and cubic epithelial epithelial cells, the epithelial cells decrease sharply in size, they acquire a spherical shape, depart from each other and remove from the basal membrane, freeing the path of phagocytes from the inflammatory process when damaged occurs. The process of damage to the epithelial tissue is accompanied by a mass amithetic and mitotic division of epithelial cells along the periphery of the area of \u200b\u200bdamage, which fill the defect.

In case of damage to the epithelium of the intestinal type, there is a rejection of damaged cells from the basal membrane and entering them into the cavity of the gastrointestinal tract, and the adjacent epithelial cells react to damage and very quickly occupy the vacant place.

6 question ....

Ferrous epitheliumsperform a secretory function. They can be located on surfaces as the epithelium of the gastric mucosa (i.e., simultaneously perform a coating or border function), or immerse itself into the thickness of the connective tissue, forming special secretory bodies.

Irony epitheliumthe variety of epithelial tissue, which consists of epithelial gland cells, which in the process of evolution acquired the master property to generate and highlight secrets. Such cells are called secretory (glandular) - glandulocytes. They expressed the polarity of the structure.

· In the basal part there are cores and organoids of general meaning.

· In the apical part of the glindulocites, the secret granules are located, and the surface of the apical part is covered by numerous microvills, which increase the distribution area of \u200b\u200bthe secret.

· The cytoplasm contains a large number of endoplasmic reticulum, a Golgi complex, mitochondria.

Cells are thin, flattened, contain little cytoplasm, the diskidoid kernel is located in the center (Fig. 8.13). The edges of the cells are uneven, so the surface as a whole resembles a mosaic. There are often protoplasmic connections between adjacent cells, thanks to which these cells are tightly connected to each other. The flat epithelium is available in the bowman capsules of the kidneys, in the lungs of the lungs and in the walls of the capillaries, where, due to its subtleties, it allows diffusion of various substances. It also forms a smooth liner of hollow structures, such as blood vessels and heart chambers, where it reduces the friction of leaking fluids.

Cubic epithelium

This is the least specialized from all epithelials; As its name indicates, its cells have a cubic form and contain a spherical kernel located in the center (Fig. 8.14). If you look at these cells from above, it can be seen that they have five- or hexagonal outlines. The cubic epithelium sweeps the ductures of many glands, such as the salivary glands and the pancreas, as well as the collective tubes of the kidney in sites that are not secretory. Cubic epithelium is also contained in many glands (salivary, mucous, sweat, thyroid), where it performs secretory functions.

Cylindrical epithelium

These are high and fairly narrow cells; Thanks to this form per unit, the epithelium area accounts for more cytoplasm (Fig. 8.15). Each cell has a kernel located at its base. Among epithelial cells, secretory-shaped cells are often scattered; In terms of its functions, the epithelium can be secretory and (or) suction. Often on the free surface of each cell there is a well-pronounced brush cut, formed microwaveswhich increase the suction and secreting cell surface. Cylindrical epithelium sweeps the stomach; The mucus secreted by glassoid cells protects the gastric mucosa from the effects of its acidic content and from digestion by enzymes. He also wipes the intestines, where again the mucus protects it from self-extinguishing and at the same time creates a lubricant that facilitates the passage of food. In the small intestine, digested food is absorbed through the epithelium into the bloodstream. Cylindrical epithelium sweels and protects many kidney channels; It also includes thyroid gland and gallbladder.

Cheerful epithelium

Cells of this tissue usually have a cylindrical shape, but they carry numerous cilia on their free surfaces (Fig. 8.16). They are always associated with glassworm cells secreting the mucus, which is moving through the bias of the cilia. The fiscal epithelium sweeps the eggs, brain ventricles, the cerebrospinal channel and the respiratory tract, where it provides the movement of various materials.

Pseudo-layer (multi-row) epithelium

When considering histological sections of the epithelium of this type, it seems that cell kernels lie at several different levels, because not all cells reach the free surface (Fig. 8.17). Nevertheless, this epithelium consists of only one cell layer, each of which is attached to the basal membrane. The pseudo-layer epithelium wipes the blade, the trachea (pseudomonic cylindrical), other respiratory tract (pseudo-coating cylindrical cylindrical) and is included in the mucous membrane of the olfactory cavities.

Epithelial fabrics or epithelium, linse the surface of the body, serous shells, the inner surface of hollow organs (stomach, intestines, bladder) and form most of the organism glands. They originated from all three germinal leaves - Ektoderm, Entoderm, Mesoderm.

Epithelium It is the layers of cells located on the basal membrane, which is a loose connective tissue. The intermediate in the epithelium almost no and the cells closely come into contact with each other. Epithelial fabrics do not have blood vessels and their nutrition is carried out through the basal membrane by the side of the connective tissue. Fabrics have a high regenerating ability.

Epithelium has a number of functions:

• Protective - Protects other fabrics from environmental exposure. This feature is characteristic of the skin epithelium;
• Nutrient (trophic) - suction of nutrients. This function is carried out, for example, epithelium gastrointestinal tract;

The structure of various types of epithelium:

A - single-layer cylindrical, b - single-layer cubic, in - single-layer flat, g - multi-row, d - multilayer flat, non-illuminating, e - multilayer flat ornamental, z1 - transitional epithelium with a stretched body wall, z2 - when the organ of the organ

• Excretory - removal from the body of unnecessary substances (CO2, urea);
• Secretoric - Most glands are built from epithelial cells.

Epithelial fabrics can be classified as a scheme. Single-layer and multilayer epithelium differ in the form of cells.

Single-layer, flat epithelium It consists of flat cells located on the basement membrane. This epithelium is called mesothelium and lifts the surface of the leaflets of the pleura, the necroserous bags and peritoneum.

Endothelium It is a derivative of mesenchyma and is a continuous plastic of flat cells covering the inner surface of blood and lymphatic vessels.

Wallows the kidney channels, outputting glands.

Consists of prismatic cells. This epithelium lifts the inner surface of the stomach, intestines, uterus, eggs, renal tubules. In the intestinal epithelium there are glass-shaped cells. This is a single-celled gland distinguishing mucus.

In the small intestine, epithelial cells have on the surface of a particular education - a cut. It consists of a large number of microvones, which increases the cell surface and contributes to the best suction of nutrients and other substances. The cells of the epithelium of the lining uterus have fixed cilia and are called fiscal epithelium.

Single-layer multi-row epithelium It is characterized by the fact that the cells of it have a different form and as a result of this, their kernel lie at different levels. This epithelium has fixed cilia and is also called fiscaling. It wores the air paths and some departments of the sexual system. Cilicular movements remove dust particles from the upper respiratory tract.

It is a relatively thick layer consisting of many cell layers. With a basal membrane, only the deepest layer comes into contact. Multilayer epithelium performs a protective function and is divided into iriet and non-peer.

Non-propelled Epithelium lins the surface of the cornea of \u200b\u200bthe eye, oral cavity and esophagus. Consists of different cells. The basal layer consists of cylindrical cells; Then there are cells of different shapes with short thick threats - a layer of spinged cells. The topmost layer consists of flat cells, gradually die and dropping.

Introgatory The epithelium covers the skin surface and is called the epidermis. It consists of 4-5 layers of cells of different in shape and executable functions. The inner layer, basal, consists of cylindrical cells capable of reproduction. The peasant cell layer consists of cells with cytoplasmic islands, with which the cells come into contact with each other. The grainy layer consists of flattened cells containing grains. The brilliant layer in the form of a brilliant tape consists of cells whose boundaries are not visible due to the shiny substance - eleidine. The horny layer consists of flat scheels filled with keratin. The most surface scales of the horn layer gradually disappear, but are replenished due to the breeding layer cells. The horny layer is distinguished by resistance to external, chemical impacts, elasticity and low thermal conductivity, which ensures the execution of the protective function of the epidermis.

Transitional epithelium It is characterized by the fact that its appearance varies depending on the state of the organ. It consists of two layers - basal - in the form of small flattened cells and coating large, slightly flattened cells. The epithelium wreens up the bladder, ureters, lochkins, renal cups. When cutting the wall of the organ, the transitional epithelium has the form of a thick formation in which the basal layer becomes multiple. If the organ is stretched, the epithelium becomes thin and the cell shape changes.

Epithelial fabric

Covers the entire outer surface of the body of human and animals, lifts the mucous membranes of hollow internal organs (stomach, intestines, urinary paths, pleura, pericardium, peritoneum) and is part of the domestic secretion glands. Highlight coating (superficial) and secretor (iron)epithelium.

The epithelial tissue is involved in the exchange of substances between the body and the external environment, performs a protective function (skin epithelium), the function of secretion, suction (intestinal epithelium), isolation (kidney epithelium), gas exchange (lung epithelium), has a greater regenerative ability.

multi-layered - transition and single-layered -

IN flat epithelium Cells are thin, compacted, contain little cytoplasm, the drive kernel is in the center, the edge is uneven. The flat epithelium sweels the alveios of the lungs, the walls of the capillaries, vessels, the cavities of the heart, where, due to its subtleties, it does diffusion of various substances, reduces the friction of current fluids.

Cubic epithelium

Cylindrical epithelium Consists of high and narrow cells.

It sweels the stomach, intestines, gallbladder, renal tubules, and also included in the thyroid gland.

Fig. 3. Various types of epithelium:

AND - single layer flat; B - single-layer cubic; IN -

Cells crazy epithelium

Non-row epithelium

Multilayer epithelium

Types of epithelial fabrics

Transitional epithelium Located in those organs that are subjected to strong stretching (bladder, ureter, renal lug).

The thickness of the transition epithelium prevents urine intake into the surrounding fabrics.

Irony epithelium

Ecocrine cells Endocrine

See more:

Epithelial tissue (synonym for epithelium) is a fabric, lining the surface of the skin, cornea of \u200b\u200bthe eye, serous shells, the inner surface of the hollow organs of the digestive, respiratory and urogenital system, as well as the forming gland.

Epithelial tissue is characterized by a high regeneration capacity.

Different types of epithelial tissue perform different functions and therefore have a different structure. Thus, the epithelial tissue that performs mainly the function of protection and separation from the external environment (skin epithelium) is always multi-layered, and some kinds are equipped with a stratum and participate in protein metabolism. Epithelial tissue, in which the function of external exchange is the leading (intestinal epithelium), always single layer; It has microwaves (brush kaym), which increases the suction surface of the cell.

This epithelium is also a ferrous, highlighting a special secret necessary to protect epithelial tissue and chemical treatment of substances penetrating through it. The kidney and nominal types of epithelial tissue perform the functions of suction, the formation of secrets, phagocytosis; They are also single-layer, one of them is equipped with a brush border, the other has pronounced recesses, on the basal surface.

In addition, some epithelial tissue have permanent narrow intercellular gaps (renal epithelium) or periodically arising large intercellular holes - shomates (non-epithelium), which contributes to the filtering and suction processes.

Epithelial fabric (epithelium, from Greek. Epi - on, over and theele - nipples) - border tissue, lining the surface of the skin, cornea of \u200b\u200bthe eye, serous shells, the inner surface of hollow organs of digestive, respiratory and urogenital systems (stomach, trachea, uterus, etc. .).

Most glands of epithelial origin.

The border position of the epithelial tissue is due to its participation in metabolic processes: gas exchange through the epithelium alveoli of the lungs; The absorption of nutrients from the intestinal lumen in blood and lymph, the separation of urine through the kidney epithelium, etc. In addition, the epithelial tissue also performs a protective function, preventing the tissues from damaging effects.

Unlike other tissues, the epithelial tissue develops from all three germ sheets (see).

From Etoderma - skin epithelium, oral cavity, most of the esophagus, cornea of \u200b\u200bthe eye; from Entoderma - the epithelium of the gastrointestinal tract; From the Mesoderm - the epithelium of the organs of the urogenital system and serous shells - mesothelium. Epithelial tissue occurs in the early stages of embryonic development. Entering the placenta, the epithelium is involved in the exchange between the mother and the fruit. Taking into account the peculiarities of the origin of epithelial tissue, it is proposed to divide it onto the skin, intestinal, kidney, nominal epithelium (mesothelium, sex epithelium) and ependimoglyal (epithelium of some senses).

All types of epithelial tissue are characterized by a number of common features: epithelium cells together form a solid reservoir located on the basal membrane through which the epithelial tissue tissue is powered by blood vessels; The epithelial tissue has a high regenerator capacity, and the integrity of the damaged reservoir is usually restored; The cells of the epithelial tissue are characterized by the polarity of the structure due to the differences in the basal (located closer to the basal membrane) and the opposite - the apical parts of the cellular body.

Within the reservoir, the bonding of neighboring cells is often carried out with the help of the premosomom - special multiple structures of submicroscopic sizes consisting of two half, each of which in the form of a thickening is located on adjacent surfaces of neighboring cells.

The slitual gap between halves is filled with substance, apparently of carbohydrate nature. If the intercellular gaps are expanded, then the despair are at the ends of the emotions of the cytoplasm of contacting cells to each other.

Each pair of such empty has a view of an intercellular bridge with light microscopy. In the epithelium of the small intestine, the gaps between adjacent cells are closed from the surface due to the merger in these places of cell membranes. Such fusion places were described as closing plates.

In other cases, these special structures are absent, neighboring cells are in contact with their smooth or winding surfaces. Sometimes the edges of the cells are tiled over each other. The basal membrane between the epithelium and the fabric is formed by a substance rich in mucopolysaccharides and containing a network of thin fibrils.

The cells of the epithelial tissue are covered with a plasma shell surface and contain organides in the cytoplasm.

In cells through which exchange products are intensified, the plasma shell of the basal part of the cell body is folded. On the surface of a series of cells, the epithelium of the cytoplasm forms small, traversed the dudder to grow - microwaves.

Epithelial fabric

They are especially many on the apical surface of the epithelium of the small intestine and the main departments of the convinced kidney tube. Here, microvils are located in parallel to each other and in the aggregate light-pointer have a strip (intestinal epithelial cuticle and brush kaym in the kidney).

Microwaves increase the suction surface of the cells. In addition, a number of enzymes were found in the microwaves of the cuticle and brush kayma.

On the surface of the epithelium of some organs (trachea, bronchi, etc.) there are cilia.

Such an epithelium, which has on its surface of the cilia, was called fame. Due to the movement of cilia from the respiratory organs, dust particles are removed, the directional current of the fluid is created in the ovitsa. The basis of the cilia, as a rule, is 2 central and 9 paired peripheral fibrils associated with derivative centrioles - basal tales. Similar structure have firing spermatozoa flavors.

With a pronounced polarity of the epithelium in the basal part of the cell, the kernel is located above it - mitochondria, the Golgi complex, centrioli.

The endoplasmic network and the Golges complex are especially developed in secreting cells. In the cytoplasm of the epithelium experiencing a large mechanical load, a system of special threads is developed - tonofibrils, creating as it were for a frame that prevents cell deformation.

The form of epithelium cells is divided into cylindrical, cubic and flat, and by the location of the cells - on the single-layer and multilayer.

In one-layer epithelium, all cells lie on the basal membrane. If the cells have the same shape, i.e. is isomorphic, then their kernels are located at one level (in one row) is a single-row epithelium. If the cells of different shape alternate in one-layer epithelium, their kernels are visible at different levels - a multi-row, anisorphic epithelium.

In the multilayer epithelium on the basement membrane, only the cells of the lower layer are located; The remaining layers are located above it, with the shape of the cell of different layers of unequal.

The multi-layer epithelium is different in the form and state of the cells of the outer layer: a multilayer flat epithelium, a multi-layered oroging (with layers of burned scales on the surface).

A special type of multilayer epithelium is the transitional epithelium of the organs of the excretory system. Its structure varies depending on the stretching of the wall of the organ. In the stretched bladder, the transitional epithelium is thinned and consists of two layers of cells - basal and coating. With the reduction of the epithelium organ sharply thickens, the shape of the base layer cells becomes a polymorphic, and their kernels are located at different levels.

Cooking cells become pear and enjoy each other.

Epithelial fabric

Epithelial fabric, or epithelium, lins the surface of the body, serous shells, the inner surface of the hollow organs, and also forms most glands. Epithelium, located on the surface of the body and organs, is called superficial or coating; This epithelium is border tissue.

The border position of the coating epithelium determines its metabolic function - suction and isolating various substances. In addition, it protects the fabrics from harmful mechanical, chemical and other influences.

The epithelium, which is part of the glands, has the ability to form special substances - secrets, as well as allocate them in blood and lymph or gonducts.

Such an epithelium is called ferrous or secretory.

The epithelial tissue, the lining surface of the body or organs, represents the reservoir of cells located on the basement membrane. Through this membrane, the epithelial tissue is powered, as it is deprived of its own blood vessels. A feature of the epithelial tissue is the small content of the intercellular substance represented mainly by the basal membrane consisting of a basic substance with a small amount of thin fibers.

In the human body, many varieties of epithelial tissue, differing not only by their origin, but also by the structure, and functional features.

The division of the epithelium (Fig. 2) on the single-layer and multi-layer is based on its cells to the basement membrane.

If all cells are adjacent to the membrane, then the epithelium is called single-layer. In cases where only one cell layer is associated with the basal membrane, and the remaining layers are not adjacent to it, the epithelium is called multilayer. In each of these two groups, epitheliums are distinguished several varieties that differ in the form of cells and other signs.

Fig. 2. The scheme of the structure of various types of epithelium.

A - single-layer cylindrical epithelium; B - single-layer cubic epithelium; In - single-layer flat epithelium; G - multiple epithelium; D - multi-layered flat non-propelled epithelium; E - multi-layered flat ornamental epithelium; Z1 - transitional epithelium with a stretched wall of the organ; Z2 - transitional epithelium when the body has gotten

Depending on the shape of the cells, flat, columnal (prismatic, or cylindrical) and cubic epithelium differ.

In addition to typical elements of the structure, epithelial cells of different organs have specific structures due to features of the function. Thus, on the free surface of the cells of the epithelium of the mucous membrane of the small intestine there are microvilles, which are growing cytoplasm, which are visible in an electron microscope. Through these microvilles, nutrients are absorbed.

Respiratory system

The cells of the mucous membrane of the nasal cavity and some other organs have increased cytoplasm in the form of cilia. Epithelium with cilia is called fiscal. In the cytoplasm of the cells of the epithelium, there are nice structures - tonofibrils that attach strength to these cells.

The strength of the epithelial tissue is also determined by the fact that the cells are tightly connected in it.

Single-layer flat epithelium (mesothelium) Waves the surface of the serous shells of the cavity of the peritoneum, pleura and pericardium. Due to the presence of such an epithelium (mesothelium), the surface of the serous shell sheets is very smooth and easily slides when the organs moves, through the mesothelium there is an intensive exchange between the serous fluid available in the cavities of the peritoneum, pleura and pericardia, and the blood flowing into the vessels of the serous shell.

Single-layer cubic epithelium Wallows the kidney channels, the ducts of many glands I am small bronchi.

Single-layer cylindrical epithelium It has a mucous membrane of the stomach, intestines, uterus and some other organs; It also includes part of the kidney channels.

This epithelium in the small intestine is equipped with microwaves forming the suction cut, and therefore is called the capecles. Among the cells of the epithelium there are glass-shaped, which are glands that allocate mucus.

Epithelial cells of uterus and uterine tubes are equipped with cilia.

Single-layer multiple cereal (ciliary) epithelium. The cells of this epithelium have different lengths, so their kernels lie at different levels, i.e. in several rows. Free ends of cells are equipped with cilia. Such an epithelium sweeps the mucous membrane of the air pathways (the cavity of the nose, the lads, three ways, bronchi) and some separations of the sexual system.

Multilayer flat epithelium Covers the surface of the skin, shelters the oral cavity, the esophagus, the cornea of \u200b\u200bthe eye, the organs are excretory: L of systems.

It is a relatively thick layer consisting of many layers of epithelial cells, of which only the deepest goes to the basal membrane. The multi-layered epithelium defines its protective function. There are three types of this epithelium: a healing, non-illuminating and transitional.

Healing Epithelium Forms a surface layer of skin and is called the epidermis. This appearance of the epithelium consists of a large number of layers of cells of various shapes and different functional purposes.

According to the morphofunctional sign, all epidermis cells are divided into five layers (Fig. 3): basal, hipgy, grainy, shiny and horny.

Fig. 3. Intressive multi-layer (flat) skin epithelium. A - with a small increase; B - with a large magnification; I - epidermis: 1 - basal layer; 2 - hipgy layer; 3 - grainy layer; 4 - brilliant layer; 5 - horny layers; 6 - output duct of the sweat gland; II - connecting fabric

The first two layers, the deepest, represented by columnar (cylindrical) and thickened epitheliocytes, which have the ability to reproduce, and therefore are called a spike layer together.

The grainy layer consists of flattened cells containing keratogial grains in the cytoplasm - a special protein, capable of turning into a corneum of keratin. The brilliant layer under the microscope has a form of a brilliant homogeneous painted tape consisting of flat cells that are at the stage of transformation into horny flakes.

This process is accompanied by cell death and accumulation of Karagin. The horny layer is the superficial layer, consists of horny flashes resembling the shape of a pad filled with a horn.

Periodically, there is a lunch of a part of the horny scales and at the same time the formation of new scales.

Non-propelled epithelium Covers the cornea of \u200b\u200bthe eye and the mucous membrane of the oral cavity and the esophagus (part of the oral epithelium can organize). It is represented by three layers: basal, spinous and layer of squamous (flat) epitheliocytes.

The basal layer consists of cylindrical cells capable of multiplication (sprouting layer). The cells of the spinged layer of an irregular polygonal shape and are equipped with small processes - "spikes". Flat cells lie on the surface of the epithelium, gradually they die and replace new.

Transitional epithelium Wallows the mucous membrane of the urinary organs (ureterals, bladder, etc.). It distinguishes two layers of cells - basal and superficial.

The basal layer is represented by small compound cells and more "large polygonal. The coating layer consists of very large cells slightly flattened form. The form of an intermediate (transitional) epithelium varies depending on the degree of stretching the urine organ.

When stretching the epithelium is thinned, and when the organ reduces it becomes thicker, the cells are shifted.

Irony epithelium It is represented by cells of different shapes, which have a property to synthesize and allocate special substances - secrets.

In ferrous cells, the Golgi complex (internal net apparatus) is well developed, which is involved in the secretion process. The cytoplasm of these cells contains secretory granules and a large amount of mitochondria. The cells of ferrous epithelium form various glands, characterized by the structure, magnitude and other signs. Depending on where they allocate their secret, all glands are divided into two large groups: glands of internal secretion, or endocrine, and the glands of external secretion, or exocrine.

Endocrine glands do not have output ducts, their secrets (hormones) are entered into lymph and blood and are spread throughout the body. Exocrine glands allocate their secret to the cavity of a certain organ or to the surface of the body.

Thus, the secret of sweat glands (sweat) is released on the surface of the skin, and the secret of the salivary glands (saliva) enters the oral cavity.

It is customary to distinguish between unicellular and multicellular exocrine glands. Unicellular include glazing cells available in the epithelium of the mucous membrane of the digestive channel and respiratory tract.

Their secret - mucus - wets the mucous membrane of these organs. All other exocrine glands are multicellular and equipped with output ducts. The dimensions of these glands vary. Some multice gland glands of microscopic size and are located in the walls of the organs, while others are complex organs.

In multicellular glands, two departments are distinguished: secretory, whose cells are synthesized and distinguished the secret, and output duct, united by cells, usually not having a secretory function.

Depending on the type of secretion, frozen (eccritine), apocryine and holocreen glands are distinguished. In frozen glands, the secretion of the secret occurs without the destruction of the cytoplasm of ferrous cells, and in the apocryan - with partial destruction. Golokrine called glands, in which the formation of the secret takes place as a result of the death of a part of the cells. Noodynakov and the composition of the secret of different glands - it can be protein, mucous membranes, protein-mucous, greasy.

Epithelial fabric. The epithelial tissue (epithelium) covers the entire outer surface of the body of human and animals, lifts the mucous membranes of hollow internal organs (stomach

Epithelial Fabric (Epithelium) Covers the entire outer surface of the body of human and animals, lifts the mucous membranes of hollow internal organs (stomach, intestines, urinary paths, pleura, pericardium, peritoneum) and is part of the domestic secretion glands.

Highlight coating (superficial) and secretor (iron)epithelium. The epithelial tissue is involved in the exchange of substances between the body and the external environment, performs a protective function (skin epithelium), the function of secretion, suction (intestinal epithelium), isolation (kidney epithelium), gas exchange (lung epithelium), has a greater regenerative ability.

Depending on the number of cellular layers and the forms of individual cells distinguish the epithelium multi-layered - Oro-oving and non-propelled, transition and single-layered - Simple column, simple cubic (flat), simple double (mesothelium) (Fig.

IN flat epithelium Cells are thin, compacted, contain little cytoplasm, the drive kernel is in the center, the edge is uneven.

Welcome

The flat epithelium sweels the alveios of the lungs, the walls of the capillaries, vessels, the cavities of the heart, where, due to its subtleties, it does diffusion of various substances, reduces the friction of current fluids.

Cubic epithelium Many glands sweeps, and also forms kidney channels, performs a secretory function.

Cylindrical epithelium Consists of high and narrow cells. It sweels the stomach, intestines, gallbladder, renal tubules, and also included in the thyroid gland.

3. Different types of epithelium:

AND - single layer flat; B - single-layer cubic; IN - cylindrical; M-one-layer seating; D-multiradinary; E -Mnogo-layer oroging

Cells crazy epithelium usually have a cylinder form, with a set on the free surfaces of the ciliation; Wallows eggs, brain ventricles, the cerebrospinal channel and the respiratory tract, where it provides transportation of various substances.

Non-row epithelium Watches the urinary paths, trachea, respiratory tract and is part of the mucous membrane of the olfactory cavities.

Multilayer epithelium Consists of several cell layers.

It will linse the outer surface of the skin, the mucous membrane of the esophagus, the inner surface of the cheek, the vagina.

Transitional epithelium Located in those organs that are subjected to strong stretching (bladder, ureter, renal lug). The thickness of the transition epithelium prevents urine intake into the surrounding fabrics.

Irony epithelium It is the main mass of those glands in which epithelial cells are involved in the formation and allocation of the necessary organisms of substances.

There are two types of secretory cells - exocrine and endocrine.

Ecocrine cells Eliminate the secret to the free surface of the epithelium and through the ducts in the cavity (stomach, intestines, respiratory tract, etc.). Endocrine Called glands, the secret (hormone) of which is released directly into blood or lymph (pituitary gland, thyroid, fork glands, adrenal glands).

In structure, exocrine glands can be tubular, alveolar, tubular-alveolar.

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Single-layer cylindrical epithelium.

Has varieties;

- Simple

- Ironistical

- Cailed

- Writing.

Single-layer cylindrical simple.Cells do not have a special organelle on the apical part, forms the outline of the output ducts of glands.

Single-layer cylindrical iron. Epithelium is called ferrous if it produces some kind of secret.

This group includes the epithelium of the gastric mucosa (example), which produces mucous secret.

Single-layer cylindrical cut. On the apical part of the cells are microvilles, which together form a brush cut.

Purpose of microvones - dramatically increase the total surface area of \u200b\u200bthe epithelium, which is important for performing the absorption function. This is the epithelium of the intestinal mucosa.

Single-layer cylindrical seating.

Epithelial tissue - structure and functions

On the apical part of the cells there are cilias that perform a motor function. This group includes the epithelium of eggs. In this case, the oscillations of the cilia are mixed with a fertilized egg toward the uterine cavity. It should be remembered that with impaired integrity of the epithelium (inflammatory diseases of the eggs), the fertilized egg "stuck" in the lumen of the egg and here for a certain time the development of the embryo continues.

It ends with a rupture of the wall of the egg (ectopic pregnancy).

Non-row epithelium.

Multi-row cylindrical semi-axial epithelium pathways (Fig. 1).

Types of cells in the epithelium:

- Cylindrical eyelashes

- Balo-shaped

- insert

Cylindrical Cells are associated with a basal membrane with their narrow base, cilia are located on a wide apical part.

Balo-shaped Cells have an enlightened cytoplasm.

Cells are also associated with the basal membrane. Functionally - single-cellular mucous glands.

2. Box and shaped cells

3. Cells

5. Insert cells

7. loose connecting fabric

Insert Cells with their wide base are associated with the basal membrane, and the narrow apical part does not reach the surface of the epithelium.

There are short and long inserted cells. Short insert cells are Cambier (source of regeneration.) Numerous epithelium. Of these, there are subsequent cylindrical seating and glazing cells.

The multi-row cylindrical camber epithelium performs a protective function. On the surface of the epithelium there is a thin film of the mucus where the microbes are settled, foreign particles from inhaled air.

Epithelia mucus ciliations are constantly moving in the direction of the dust and is removed by coughing or twisting.

Multilayer epithelium.

Multi-layered epithelium varieties:

- multi-layered flat ornamental

- multi-layered flat non-illuminating

- Transition.

The multi-layered flat ornamental epithelium is the epithelium of the skin (Fig. 2.).

1 (a) basal layer

1 (b) hipped layer

1 (c) grainy layer

1 (g) shiny layer

1 (e) horny layer

Layers as part of the epithelium:

- Basal

- Shipovoid

- Granular

- Brilliant

- Rogova

Basal layer - This is one layer of cylindrical cells.

All layer cells are associated with a basal membrane. The cells of the basal layer are constantly divided, i.e. are Cambier (source of regeneration) multilayer epithelium. The composition of this layer has other types of cells to be considered in the section "Private Histology".

Hipgy layer Consists of several layers of polygonal cells. Cells have processes (nips), with which are firmly related to each other.

In addition, the cells are connected and contacts like Desmaas. In the cytoplasm of cells there are tonofibrils (special organelles) additionally reinforcing cytoplasm cells.

The cells of the hipged layer are also capable of dividing.

For this reason, the cells of the specified layers are combined under the general name - the sprout layer.

Granular layer- These are several layers of diamond-shaped cells. In the cytoplasm of cells many large granules of protein - keratogialin. The cells of this layer are not capable of dividing.

Brilliant layer Consists of cells that are at the stage of degeneration and death.

Cells are poorly contoured, they are impregnated with protein eleidine. On the painted preparations, the layer has a look of a brilliant strip.

Epithelium is layers covering the internal and external surfaces of organisms. Its main function is to protect the relevant authorities from mechanical damage and infection. In those places where the body's fabric is subjected to constant loads and friction and "wear", epithelium cells multiply at high speed. Often in places of large loads of the epithelium compacted or or ends. The free surface of the epithelium can also perform the functions of suction, secretion and excretion, perceive irritation.

Epithelial cells are held together by a cementing substance containing hyaluronic acid. Since blood vessels are not suitable for epithelium, the supply of oxygen and nutrients occurs by diffusion through the lymphatic system. Nervous endings can penetrate the epithelium.

Depending on the cell form and the number of cellular layers of the epithelium is divided into several types.

The least specialized of all is Cubic epithelium. Its cells, as follows from the name, have a cubic form in cross section. This type of epithelium lifts the ducts of many glands, and also performs secretory functions inside them.

Cells Flat epithelium subtle and flattened; By protoplasmic connections, they are tightly connected to each other. Due to this, they do not interfere with diffusion of various substances in those organs that these cells are lined up: alveoli lungs, the walls of the capillaries.

High and rather narrow cells Cylindrical epithelium lined the stomach and intestines. Boxias scattered among cylindrical cells isolated a mucus that protects these organs from self-extinguishing, and at the same time creates lubricant helps in advancement of food. On the free surface of the cells, microvills are often encountered, increasing the suction surface.

II. Multilayer epithelium.

1. multi-layered flat non-illuminating

2. Multilayer flat ornamental

3. Transition

In one-layer ep. All cells without exception are directly connected, (in contact) with a basal membrane. In a single-layer single-row epithelium, all cells are in contact with the basal membrane; Have the same height, so the kernels are located at one level.

Single-layer flat epithelium - consists of one layer of sharply flattened polygonal cells (polygonal); The base (width) of cells is greater than height (thickness); There are few mitochondria organoid cells, single microvilles are encountered, pinocytous bubbles are visible in the cytoplasm. Single-layer flat epithelium widespread serous covers (peritoneum, pleura, oolely bag). With respect to endothelium (cells lining blood and lymphatic vessels, heart cavities) Among the histologists of a single opinion, there is no: one belongs to the endothelium to one-layer flat epithelium, others to the connecting tissue with special properties. Sources of development: Endothelium develops from mesenchym; Single-layer flat epithelium of serous covers - from splashnotes (ventral part of the mesoderma). Functions: demarcation, reduces the friction of the internal organs by separating the serous fluid.

Single-layer cubic epithelium- On a cut in cells, the diameter (width) is equal to height. It is found in the output ducts of the exocrine glands, in convincing kidney tubules.

Single-layer prismatic (cylindrical) epithelium - on a slice of cell widths less than height. Depending on the characteristics of the structure and the function distinguish:

Single-layer prismanie iron, it is in the stomach, in the cervical cervical channel, specialized for continuous mucus production;

Single-layer Prismatic cut, lines the intestine, on the apicial cell surface there is a large number of microvones; Specialized for suction.

Single-layer prismatic semicircle, lins the fallopian tubes; On the apicial surface epithelocytes have cilia.

Regeneration of single-layer single-row epitheliumit occurs at the expense of stem (cambial) cells, evenly scattered among other differentiated cells.

Single-layer multi-row fixed epithelium - all cells are in contact with the basal membrane, but have different heights and therefore the cores are located at different levels, i.e. In several rows. Waves the air paths . The composition of this epithelium distinguishes the varieties of cells:

Short and long insert cells (small stem cells unoccupied and among them; provide regeneration);

Wildlife cells - have the shape of a glass, the dyes are poorly perceived (in the preparation - white), produce mucus;

Cells, on the apical surface are fixed cilia.

Function: Cleaning and moisturizing undergoing air.

Multilayer epithelium - consists of several cell layers, and with the basal membrane contacts only the lowest number of cells.

1. Multilayer flat non-propelled epithelium - Writes the front (mouth cavity, chuck, esophagus) and the final department (anal rectum) of the digestive system, the cornea. Consists of layers:

a) the basal layer - the cylindrical shape of epithelocytes with a weavavasophilic cytoplasm, often with a figure of mitosis; In a small amount of stem cells for regeneration;

b) a gipped layer - consists of a significant number of layers of cellular shape cells, cells are actively divided.

c) Pokroval cells are flat, aging cells, not divided, from the surface gradually lisches. Source of development: Etoderma. Proportal plate as part of an entoderm front intestine. Function: Mechan. protection.

2. Multilayer flat ornamental epithelium - This is the skin epithelium. Developed from Etoderma, performs a protective function - protection against mechanical damage, radiation, bacterial and chemical impact, distinguishes the organism from the environment. Consists of layers:

a) basal layer - in many respects it looks like a similar layer of multi-layer non-propelled epithelium; Additionally: Contains up to 10% melanocytes - corrosion cells with inclusions of melanin in cytoplasm - provide protection against UFL; There is a small amount of Merkel cells (included in the mechanoreceptor); Dendritic cells with a protective function by phagocytosis; The epithelialocytes contain tonofibrils (organoid specials. destination - provide strength).

b) hipgy layer - from epitheliocytes with spit -ide outgrows; There are dendrocytes and blood lymphocytes; Epithelocytes are still divided.

c) grainy layer - of several rows of extended flat-oval cells with basophilic granules of keratogial (precursor of the horn substance - keratin) in the cytoplasm; Cells are not divided.

d) shiny layer - cells are completely filled with elaidin (it is formed from keratin and spree products of tonofibrils), reflecting and strongly refractive light; Under the microscope of the cells of cells and nuclei is not visible.

e) a layer of horny scales - consists of horny keratin plate plates containing bubbles with fat and air, keratosomes (correspond to lysosomes). From the surface of the flakes are listed.

3. Transitional epithelium - wipes hollow organs, the wall of which is capable of severe stretching (pelvis, ureters, bladder). Layers:

The basal layer (of small dark low-rotational or cubic cells - unoccupied and stem cells, provide regeneration;

The intermediate layer is made of large pear cells, a narrow basal part in contact with the basal membrane (the wall is not stretched, so the epithelium is thickened); When the wall of the organ is stretched, pear-like cells are reduced in height and are located among basal cells.

Coating cells - large dome-shaped cells; With a stretched wall of the body, the cells are applied; Cells are not divided, gradually listens.

Thus, the structure of the transition epithelium varies depending on the state of the organ: when the wall is not stretched, the epithelium is thickened due to the "displacement" of parts of the cells from the basal layer into the intermediate layer; With a stretched wall, the thickness of the epithelium decreases by flattening the coating cells and the transition of the part of the cells from the intermediate layer to the basal. Sources of development: EP. Lohanks and ureter - from mesonfral duct (derivative segment legs), EP. bladder - from the Entoderma of Allantom and Entoderma Cloaca . The function is protective.

Irony epithelium

Irony ep. (HE) specialized in the development of the secret. Zhe forms glands:

I. Endocrine glands - do not have output ducts, the secret is allocated directly into blood or lymph; plentiful blood supply; Hormones or biologically active substances produce strongly regulating the organs and systems even in small doses.

II. Ecocrine glands - Hasual ducts, distinguish the secret to the surface of the epithelium (on the outer surfaces or in the cavity). Consist of terminal (secretory) departments and output ducts.

Principles of classification of exocrine glands:

I. According to the structure of output ducts:

1. Simple - output duct does not branch.

2. Complex - output duct branching.

II. In structure (form) of secretory departments:

1. Alveolar - Secretor department in the form of alveoli, bubble.

2. Tubular - Secreth. Division in the form of a tube.

3. Alveolar-tube (mixed form).

III. In the ratio of output ducts and secretory departments:

1. Unbranched - one secretory opens into one output duct

division.

2. Branched - in one output duct opens several secrets

car departments.

IV. By type of secretion:

1. Meroccian - When secretion, cellility is not violated. Character

tERNO for most glands.

2. Apokrinovye (Apex - the top, Krinio - isolation) - during secretion, partially collapsing (reversed) the top of the cells (PR .: Milk glands).

3. Golokrinovye - When secretion, the cell is completely destroyed. PR.: Sing glands of leather.

V. On localization:

1. Endoepithelial - Unicellular iron in the thickness of the coating epithelium. PR.: Balo-shaped cells in intestinal epithelium and aircraft. ways.

2. Exoepithelial glands - The secretory department lies outside the epithelium into the tissues.

Vi. By the nature of the Secret:

Protein, mucous, mucous-protein, sweat, greasy, dairy, etc.

Phase secretion:

1. Access to the ferruginous cells of the source materials for the synthesis of secretion (amino acids, lipids, mineral substances, etc.).

2. Synthesis (in EPS) and accumulation (in PC) in ferruginous secrets.

3. Allocation of the Secretary.

For the cells of ferrous epithelium, the presence of an organelle: Eps granular or agranular type (depending on the nature of the secret), the plate complex, mitochondria.

Regeneration of ferrous epithelium - In most glands, the regeneration of ferrous epithelium occurs by dividing unoccalued (cambial) cells. Separate glands (salivary glands, pancreas) stem and unoccupied cells do not have intracellular regeneration - i.e. Update inside the cells of worn organoids, in the absence of ability to divide the cells.