They carry out a large number of useful functional work in the body, without which it is impossible to submit our lives. The main of them is the elimination of excess water and concluding products of metabolism. It happens in the smallest kidney structures - nephrons.

In order to go to the smallest kidney units, it is necessary to disassemble the general structure. If you consider the kidney in the context, then in its form it resembles Bob or beans.

A person is born with two kidneys, but, however, there are exceptions when only one kidney is present. They are located at the posterior wall of the peritoneum, at the level of I and II of the lumbar vertebrae.

Each kidney weighs about 110-170 grams, its length is 10-15 cm, the width is 5-9 cm, and the thickness is 2-4 cm.

The kidney has a rear and front surface. The rear surface is located in the renal bed. It resembles a large and soft bed, which is lifted with lumbar muscle. But the front surface comes into contact with other neighboring authorities.

The left kidney is in contact with the left adrenal gland, the colon, and the pancreas, and the right is communicated with the right adrenal gland, a thick and small intestine.

Leading structural components of the kidney:

• Renal capsule is her shell. It includes three layers. The fibrous kidney capsule - in its thickness, quite loose, has a very strong structure. Protects the kidney from various damaging effects. Fat capsule - a layer of adipose tissue, which in its structure is gentle, soft and loose. Protects the kidney from shocks and blows. Outdoor capsule - renal fascia. Consists of fine connective tissue.
• The kidney parenchyma is a fabric that consists of several layers: cortical and brainstant. The latter consists of 6-14 renal pyramids. But the pyramids themselves are formed from collective tubules. In the cortical substance there are nephrons. These layers are clearly distinguishable in color.
• Lohanka Kidney is a deepening, similar to a funnel, which receives from nephron. It consists of a cup of different caliber. The smallest is a cup of I order, the urine penetrates from the parenchyma. Connecting, small cups, form larger - cups II orders. There are three such cups in the kidney around three. When merging these three cups, renal pelvis is formed.
• Renal artery is a large blood vessel, having branched off the aorta, it delivers the stuck blood in the kidney. Approximately 25% of the whole blood comes every minute to the kidney for cleansing. During the day, renal artery supplies the kidney about 200 liters of blood.
• Renal vein - on it already purified blood from the kidneys falls into a hollow vein.

Canal holder coming out of the capsule is called the convulsion channel I of the order. He really is not even, but convulsed. Passing through the brain layer of the kidney, this channel forms a loop of gene and turns back toward the cortical layer. On his way, convoluted channels makes several turns and in obligatory comes into contact with the base of the glull.

In the cortex layer, channel II channel is formed, it is poured into a collecting tube. A small amount of collective tubes, connecting together, is combined into output ducts, moving to the renal pelvis. It is these tubes, moving to the cerebral substance, form brain rays.

Types of nephronov

These types are distinguished due to the specificity of the lavetling of the glomeruli in the korea, the tubules and the features of the composition and localization blood vessels. These include:

• cork - occupy approximately 85% of the total number of nephrons
• yUSTAMEDULLARY - 15% of the total

Cork nephrons are the most numerous and also have a classification within them:

1. Superficial or them are also called superficial. main feature They are in the location of the kidney bodies. They are in the outer layer of the kidney cortical matter. Their number of approximately 25%.
2. Intraporous. They have Malpihary Taurus are located in the middle part of the cortical matter. The number is prevalent - 60% of all nephrons.

Cork nephrons have a relatively shortened loop of Gennet. Because of its small sizes, it can only penetrate into the outer part of the kidney cerebral.

The formation of primary urine is the main function of such nephrons.

In the YuCstamedullar Nephron, Malpigiy's calves are found at the base of the cortical substance, are almost on the brain layer line. The loop of Genla is more prolonged than that of cortical, it is infiltrated so deep in the brain layer, which reaches the peaks of the pyramids.

These nephrons in the brainstant form a high osmotic pressure that it is necessary that concentration occur (increase in concentration) and the reduction of finite urine.

Function nephron

The function lies in the formation of urine. This stadium process and consists of 3 phases:

• filtration
• reabsorption
• secretion

In the initial phase is formed primary urine. In the capillary glomers of nephron plasma of blood purified (ultrafiltered). Plasma cleansing due to the pressure difference in the glomerular (65 mm Hg) and in the nephron shell (45 mm Hg. Art.).

About 200 liters of primary urine is formed in the human body per day. This urine has similar to blood plasma composition.

In the second phase - reabsorption occurs re-absorption of the substances of the primary urine necessary for the body. These substances include:, water, various useful salts, dissolved amino acids and glucose. It happens in the proximal convinced canal. Within which there are a large number of vests, they increase the area and suction rate.

Of the 150 liters of primary urine, only 2 liters of secondary urine are formed. It does not have important nutrients for the body, but the concentration of toxic substances increases greatly: urea, uric acid.

The third phase is characterized by highlighting harmful substances In the urine that have not passed the renal filter: various dyes, medicinal products, poisons.

The structure of the nephron is very complicated, despite its small sizes. Surprisingly, almost every component of the nephron performs its function.

Nov 7, 2016 Violetta Leak

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The tubular part of the nephron is customary to divide into four departments:

1) main (proximal);

2) the thin segment of the loop of Genela;

3) distal;

4) Collective tubes.

Chief (proximal) department consists of winding and straight parts. Cells convoluted Have a more complex structure than cells of other nephron departments. It is high (up to 8 μm) cells with brush cut, intracellular membranes, a large number of correctly oriented mitochondria, well-developed lamellar complex and an endoplasmic network, lysosomes and other ultrastructures (Fig. 1). In their cytoplasm there are many amino acids, basic and acidic proteins, polysaccharides and active SH groups, highly active dehydrogenases, diaphorases, hydrolase [Serov V. V., Ufimseva A. G., 1977; Jakobsen N., Jorgensen F. 1975].

Fig. 1. Scheme of ultrastructure cells of tubules of various departments of nephron. 1 - cell convoluted part of the main department; 2 - cell of the direct part of the main department; 3 - cell of the thin segment of the loop of Genla; 4 - cell straight (ascending) part distal department; 5 - cage convoluted part of the distal department; 6 - "Dark" cell of the binder department and a collecting tube; 7 - "bright" cell of the binder and collecting tube.

Cells straight (descending) part of the main department Basically, there are the same structure as the cells of the convulse part, but the finger-shaped brush cuts of brush cuts are coarser and short, intracellular membranes and mitochondria less, they are not so strictly oriented, significantly less cytoplasmic granules.

The brush cut consists of numerous finger-shaped cytoplasm, coated with cell membrane and glycocalix. Their number on the cell surface reaches 6500, which increases the work area of \u200b\u200beach cell 40 times. This information is given an idea of \u200b\u200bthe surface on which the exchange in the proximal diversity of the tubules is made. An alkaline phosphatase activity, ATP-Ase, 5-nucleotidases, aminoptidases and a number of other enzymes have been proved in the brush kaxque. The brush cut membrane contains a sodium-dependent transport system. It is believed that glycocalix, covering the microvascular brush cuts, penetrate for small molecules. Large molecules come into channels using pinocytosis, which is carried out due to crater-shaped recesses in the brush cut.

Intracellular membranes are formed not only by bends of BM cells, but also lateral membranes of neighboring cells, which, as it were, overlap each other. Intracellular membranes are essentially intercellular, which serves as active fluid transport. At the same time, the main importance in transport is given to a basal labyrinth formed by the priests of the BM inside the cell; It is considered as a "single diffusion space."

Numerous mitochondria are located in the basal part between intracellular membranes, which creates the impression of their correct orientation. Each mitochondria is thus enclosed in a chamber formed by folds of intra and intercellular membranes. This allows the products of enzymatic processes developing in mitochondria, it is easy to go beyond the cells. The energy generated in mitochondria serves both the transport of substance and the secretion carried out by the granular endoplasmic network and the plate complex, which undergoes cyclic changes to the various phases of the diurea.

Ultrastructure and fermento cells of the Channels of the main department explain its complex and differentiated function. Brush cut, like a labyrinth of intracellular membranes, is a kind of device for colossal by volume of reabsorption functions performed by these cells. The enzyme transport system of the brush cutter-dependent on sodium provides the reabsorption of glucose, amino acids, phosphates [N. Yu. V. N., 1974; Kinne R., 1976]. With intracellular membranes, especially with a basal labyrinth, the reabsorption of water, glucose, amino acids, phosphates and a number of other substances that the sodium-dependent transport system of the labyrinth membrane performs.

Of particular interest is the question of the canalic reabsorption of protein. They consider it proven that the entire protein filtering in the glomers is reabsorbed in the proximal diversity of the tubules, which explains its absence in the urine healthy man. This provision is based on many studies performed, in particular, using an electron microscope. Thus, the transport of the protein in the cage of the proximal tube is studied in experiments with the microinjection of the labeled ¹ ³¹i albumin directly into the rat channel with the subsequent electron microscopic radiography of this tube.

Albumin is primarily found in the invaginates of the brush cut membrane, then in pinocytous bubbles that merge in the vacuole. The protein with vacuoles then appears in the lysosomes and plate complex (Fig. 2) and is split by hydrolytic enzymes. Most likely, the "main efforts" of high dehydrogenase, diaphrenic and hydrolylase activity in the proximal diversity of the tubules are directed towards the protein reabsorption.

Fig. 2. Scheme of the reabsorption of protein by the cage of tubules of the main department.

I - micropinocytosis at the base of the brush cut; MVB-Vacuoles containing ferrine protein;

II - a vacuole (a) filled with ferritin (a) move to the basal part of the cell; b - lysosome; B - Merge of lysosomes with a vacuole; Mr. lysosomes with incorporated protein; AG is a plate complex with tanks containing CF (painted black);

III - allocation through BM low molecular weight fragments of reabsorbed protein, formed after "digestion" in lysosomes (shown by double arrows).

In connection with these data, the mechanisms of "damage" the tubules of the main department become understandable. With a NA of any genesis, proteinurial states of changes in the epithelium of the proximal separation, in the form of protein dystrophy (hyalin-drip, vacuole) reflect the resorption insufficiency of the tubules in the conditions of an increased treatment of the glomerular filter for the protein [Davydovsky I. V., 1958; Serov V. V., 1968]. There is no need to see in changes in the channels at the National Assembly, primary dystrophic processes.

Equally, it is impossible to consider proteinuria as a result of only an increased intake of the glomerular filter. Proteinuria with nephrosis reflects both the primary damage to the kidney filter and the secondary exhaustion (blockade) of enzyme systems of the tubules carrying the protein reabsorption.

With a number of infections and intoxications of the blockade of enzyme systems of the cells of the channel of the main department, it may be acute, since these tubules are first subjected to the action of toxins and poisons in their kidney elimination. Activation of the hydrolyzes of the Lisosoma Cell apparatus completes in some cases a dystrophic process of the development of cell necrosis (acute nephrisosis). In the light of the given data, the pathology of the "dropping" of the enzymes of the kidney channels of hereditary order (the so-called hereditary canal fermentopathy) becomes. A certain role in the damage to the tubular (tubulolysis) is allocated with antibodies reacting with an antigen of tubular basal membrane and brush cut.

Cells of the thin segment of the loop Genla Characterized by that feature that intracellular membranes and plates cross the cell body for its entire height, forming a slot to 7 nm wide in the cytoplasm. It seems that the cytoplasm consists of separate segments, with a part of the segments of one cell, as it should be inclined between the segments of the neighboring cell. The fine segment of the fine segment reflects the functional feature of this nephron department, which, as an additional adaptation, reduces the filtration charge of water to a minimum and provides its "passive" resorption [Ufimseva A. G., 1963].

The coented operation of the fine segment of the loop of Genela, the tubules of the direct part of the distal separation, collecting tubes and direct vessels of the pyramid provides osmotic concentration of urine based on the countercurrent multiplier. New ideas about the spatial organization of the countercurrent system (Fig. 3) are convinced that the concentrating activity of the kidney is provided not only by the structural and functional specialization of various departments of the nephron, but also a highly specialized interpretation of the tubular structures and kidney vessels [Perov Yu. L., 1975 ; KRIZ W., LEVER A., 1969].

Fig. 3. The scheme of the arrangement of the structures of the countercurrent system in the cinestic cerebral substance. 1 - arterial straight vessel; 2 - venous straight vessel; 3 - a thin segment of the loop of Genela; 4 is the direct part of the distal department; St - collecting tubes; K - Capillaries.

Distal department Channels consists of a straight line (ascending) and convoluted parts. The cells of the distal department ultrastructantly resemble the cells of the proximal department. They are rich in cigar-like mitochondria that fill the spaces between intracellular membranes, as well as cytoplasmic vacuoles and granules around the kernel, located apical, but are devoid of brush cut. The epithelium of the distal department is rich in amino acids, basic and acidic proteins, RNA, polysaccharides and reactive SH groups; It is characterized by a high activity of hydrolytic, glycolytic enzymes and enzymes of the Krebs cycle.

The complexity of the device of cells of the distal tubules, the abundance of mitochondria, intracellular membranes and plastic material, high enzymatic activity indicate the complexity of their function - optional reabsorption aimed at maintaining the constancy of the physicochemical conditions of the inner medium. Optional reabsorption is regulated mainly by the hormones of the rear lobe of the pituitary gland, adrenal glands and southern kidneys.

The place of application of the antidiuretic hormone hormone (ADG), in the kidney, the "histochemical springboard" of this regulation is the hyaluronic acid system - hyaluronidase, laid down in the pyramids, mainly in their papillas. Aldosterone, according to some data, and cortisone affects the level of distal reabsorption by directly inclusion in the enzyme system of the cell that transfers sodium ions from the enlightenment of the Canalian in the intertension of the kidney. Of particular importance in this process belongs to the epithelium of the direct part of the distal department, and the distal effect of aldosterone is mediated by the secretion of renin, fixed behind the south cells. Angiotensin, formed by renin, not only stimulates the secretion of aldosterone, but also participates in sodium distal reabsorption.

In the convoluted part of the distal department of the Canal, where it comes to the pole of the vascular glorula, distinguish Macula Densa. Epithelial cells in this part become cylindrical, their kernels are hyperchromic; They are lined with a polyizor, and there is no continuous basal membrane. Macula Densa cells have close contacts with granulated epithelioid cells and LACIS cells of the south, which ensures chemical composition The urine of the distal canal on glomerural blood flow and, on the contrary, the hormonal influences of the south on Macula Densa.

With a structural and functional feature of the tubules of the distal department, their increased sensitivity to oxygen starvation is associated with a certain extent their selective lesion in acute hemodynamic damage to the kidneys, in the pathogenesis of which the main role is played by deep disorders of the renal blood circulation with the development of the anxity of the tubular apparatus. In the conditions of acute anxity, the cells of the distal tubules are exposed to the toxic acidic urine-containing products, which leads to their accuracy up to necrosis. In a chronic aloculation of the cell of the distal tube, more often than the proximal, atrophy are subjected.

Collective tubeslined with cubic, and in the distal sections with cylindrical epithelium (light and dark cells) with a well-developed basal labyrinth, high-dimensional water. The secretion of hydrogen ions is associated with dark cells, they found high activity of carboanhydrase [Zofarov K. A. et al., 1974]. Passive vehicles of water in collective tubes is provided by the features and functions of the countercurrent system.

After the description of the nestophysiology of nephrone, it should be highlighted on its structural and functional difference in different departments of the kidney. On this basis, cortical and yuchstamedullary nephrons distinguish between the structure of glomes and tubules, as well as the originality of the function; Different and blood supply to these nephrons.

Clinical nephrology

ed. EAT. Tareev

Nephron is the main component of a human kidney unit. It not only forms the structure of the kidney, but also responsible for some of its functions. The nephrons ensure blood filtering occurring in a Calesley of Sillyansky-Bowman, and the subsequent reabsorption of useful elements in the tubules and loops of Genla.

Each kidney has about a million nephrons with a length of 2 to 5 centimeters. The number of these units depends on the age of a person: the elderly people are much smaller than that of young people. Due to the fact that the nephrons are not regenerated, after 39 years the process of their annual decrease of 1% of the total is begins.

According to scientists, only 35% of all nephrons perform the task. The rest of their number is a kind of reserve so that the kidney continues to clean the body even in emergency situations. It is worth considering in more detail how neneron is arranged and what is its functions.

What kind of structure has nephron

The structural unit of the kidney has a complex structure. It is noteworthy that each of its component performs a specific function.

Nephron is designed so that inside the loop initially does not have differences from the proximal tubule. But just below the lumen becomes narrower and acts as a filter for sodium entering the tissue fluid. After some time, this liquid turns into hypertensive.

• The distal channels of the initial department touches the capillary glider in the place where it is brought and enduring arteries. This channel is rather narrow, inside does not have a villion, and the outside is covered with a folded basal membrane. It is in it that the process of reabsorption Na and water and the secretion of hydrogen ions and ammonia occurs.
• Binding channels where watering comes from the distal department and moves to the collecting tube.
• A collective tube is considered to be the final particle of the tubular system and is formed by the rose of the ureter.

There are 3 types of tubes: cortical, outer zone of the cerebral and inner zone of the brainstant. In addition, experts note the presence of nipple ducts that have small renal cups. It is in the cortical and brain departments of the tube and the process of forming the final urine.

Are distinguishes possible?

The diagram of the nephron structure may differ slightly depending on its type. The difference between these elements is to find them, the depth of the tubules and the location and the dimensions of the club. Loop is played with a big role and the size of some nephron segments.

Types of nephronov

Doctors distinguish 3 types of kidney structural elements. It is worth describing each of them in more detail:

• Surface or cortic nephron, which is a kidney taurus, located in 1 millimeter from its capsule. They are characterized by a shorter loop of Genlen and make up about 80% of the total structural units.
• Intrakortical nephron, the renal caller is located in the middle bark. Looped Genla here both long and short.
• Yuchstamedullar Nephron with renal calf, located on the top of the border of the cortical and brainstant. This element has a long loop of Genela.

Due to the fact that the nephrons are a structural and functional unit of the kidney and purify the body from the products of the processing of substances, in it entering it, the person lives without slags and other harmful elements. If the nephron device is damaged, it can provoke intoxicating the entire body that threatens renal failure. This suggests that at the slightest failures in the work of the kidneys, it is necessary to immediately apply for qualified help of physicians.

What functions perform nephrons

The structure of nephron is multifunctional: each separately taken nephron consists of functioning elements that work simply and provide normal kidney activities. The phenomena observed in the kidneys are conventionally divided into several stages:

• Filtration. In the first stage in the Capsule of Sillyansky, urine is formed, which is filtered by blood plasma in the glomerular capillaries. This phenomenon is carried out due to the difference between the pressure indices inside the shell and the capillary glider.

Blood is filtered by a peculiar membrane, after which moves to the capsule. The composition of the primary urine is practically identical to the composition of blood plasma, for it is rich in glucose, excess salts, creatinine, amino acids and several low molecular weight compounds. A certain amount of these inclusions is delayed in the body, and some of it is displayed.

Taking into account how Nephron functions, it can be argued that the filtration proceeds at a speed of 125 milliliters per minute. The scheme of his work is never violated, which indicates a processing of 100 - 150 liters of primary urine every day.

• Reabsorption. At this stage, the primary urine is again filtered, which is necessary in order for such beneficial substances such as water, salt, glucose and amino acids in order for the body. The main element here is the proximal channels, the villus inside which it helps to increase the volume and speed of suction.

When the primary urine goes through the tube, almost all fluid goes into the blood, as a result of which urine remains no more than 2 liters.

All elements of the nephron structure, including nephron capsule and loop, take part in reabsorption. There are no secondary urine the necessary organism Substances, but it can be detected by urea, urinary acid and other poisonous inclusions that need to be output.

• Secretion. In the urine, hydrogen, potassium and ammonia, contained in the blood appear in the urine. They can come from medicines or other toxic compounds. Thanks to calcium secretion, the body is getting rid of all these substances, and acid Alkaline Balance fully restored.

When urine passes the renal caller, passes through filtration and processing, it is assembled in renal lochs, moves with ureters in bladder and excreted from the body.

Preventive measures of the death of nephrons

For the normal functioning of the body, a third part of all the structural elements of the kidneys are sufficient. The remaining particles are connected to operation during an increased load. An example is the operation, during which one kidney was removed. This process involves the laying on the remaining organ. In this case, all nephrone departments that are in reserve become active and performing the functions.

Such a mode of operation copes with liquid filtering and allows the body to not feel the absence of one kidney.

In order to prevent a dangerous phenomenon in which the nephron disappears, several uncomplicated rules should be followed:

• Avoid or tool to treat diseases of the urogenital system.
• Do not allow the development of renal failure.
• Eat and lead healthy image Life.
• Apply for the help of physicians when any disturbing symptoms occur, which indicate the development of the pathological process in the body.
• Observe elementary personal hygiene rules.
• Feared sexually transmitted infections.

The functional unit of the kidney is not able to restore, so kidney disease, injuries and mechanical damage leads to the fact that the amount of nephrons is reduced forever. This process explains the fact that modern scientists are trying to develop such mechanisms that can restore the functions of nephrons and significantly improve the work of the kidneys.

Experts recommend not to launch emerging diseases, for they are easier to prevent them than heal. Modern medicine has achieved large heights, so many diseases are successfully treated and leave severe complications.

Nephron is not only the main structural, but also the functional unit of the kidney. It is here that the most important stages are undergoing information about how the structure of nephron looks like, and which functions it performs, it will be very interesting. In addition, the features of the functioning of nephrons can clarify the nuances of the renal system

Nephron structure: renal caller

Interestingly, in mature kidney a healthy person is from 1 to 1.3 billion nephrons. Nephron is a functional and structural kidney unit, which consists of renal calf and the so-called loop of Gennet.

The renal caller itself consists of Malpigiyevoy Gulp and Bowman Capsules - Sillyansky. To begin with, it is worth noting that the tangler actually represents a combination of small capillaries. Blood falls here through the prigning artery - plasma is filtered here. Blood remaining is derived by the leading arteriole.

Bowman's capsule - Sillyansky consists of two sheets - internal and external. And if the outer leaf is an ordinary fabric of the structure of the internal sheet deserves more attention. The inner part of the capsule is covered with poverty - these are cells that perform the role of an additional filter. They pass glucose, amino acids and other substances, but prevent the movement of large protein molecules. Thus, a primary urine is formed in the renal caller, which differs from only the lack of large molecules.

Nephron: the structure of the proximal tube and loops Genla

The proximal canal is an education that connects the renal caller and loop in Genela. Inside the channel has a villus that increase the total area of \u200b\u200bthe inner lumen, thereby increasing reabsorption indicators.

The proximal channel is smoothly moving into a downward portion of the loop of gene, which is characterized by a small diameter. The loop is lowered in the brain layer, where the own axis is 180 degrees and rises - the rising part of the loop is beginning here, which has much large sizes and, accordingly, the diameter. Ascending loop rises to about the level of the glorify.

Nephron structure: distal tubules

The ascending part of the loop of Genla in the cortical substance passes into the so-called distal winding canal. It comes into contact with the glomerus and contacts the proportion and remote arteriols. The final absorption of beneficial substances is carried out here. The distal channel passes into the finite department of the nephron, which in turn flows into the collecting tube carrying the liquid in

Classification of nephramin

Depending on the location location, it is customary to allocate three main types of nephrons:

• cortical nephrons constitute about 85% of all structural units in the kidney. As a rule, they are located in the external kidney core, about which, in fact, testifies their name. The building of the nephron of this type is slightly different - the loop of Genla here is small;
• yuCstamedullar Nephron - Such structures are just between the brain and cortical layer, have long loops of Genla, which deeply penetrate the brain layer, sometimes even reaching the pyramids;
• subcapsular nephrons - structures that are located directly under the capsule.

It can be noted that the structure of the nephron fully corresponds to its functions.

The tangle is covered with visceral epithelium (undercatics), which the vascular pole of the glider goes into the parietal epithelium of the Bowman capsule. Bowman (blade) space is directly moving into the clearance of the proximal convulsion canal. The blood enters into the vascular pole of the Gulletter through the afferent (bringing) arteriole and, after passing along the loop of the capillaries of the Gulk, leaves it on the efferent (enduring) arteriole, having a smaller clearance. Compression of the ending arteriole increases the hydrostatic pressure in the glomerular, which contributes to filtering. Inside the glider, afferent arteriol is divided into several branches, which, in turn, give rise to capillasses of several rally (Fig. 1.4 a). There are about 50 capillary loops in the glomeruloma, between which anastomoses were found, allowing the glumeure as a "dialying system". The heap capillary wall is a triple filter, which includes a phenostrized endothelium, glomerular baseal membrane and slotted diaphragms between the legs of the undercite (Fig. 1.4 b).

Figure 1.4. The structure of the Gulletter (J.C.Jennet 1995). A - tangle, aa - afferent arteriol (electron microscopy). B - Capillary Capillary Loop Frame

The passage of molecules through the filtration barrier depends on their size and electrical charge. Substances with molecular weight\u003e 50.000 and almost not filtered. Due to the negative charge in normal structures of the glomerular barrier, anions are delayed to a greater extent than cations. Endothelial cells There are pores or phenetres with a diameter of about 70 nm. Pores are surrounded by glycoproteins having a negative charge, represent a peculiar sieve through which the plasma ultrafiltration occurs, but the uniform elements of the blood are delayed. Glomerular basal membrane (GBM) represents a continuous barrier between blood and cavity capsule, and in an adult has a thickness of 300-390 nm (in children thinner - 150-250 nm) (Fig. 1.5). GBM also contains a large number of negatively charged glycoproteins. It consists of three layers: a) Lamina Rara EXTERNA; b) Lamina Densa and c) Lamina Rara Interna. An important structural part of the GBM is the type IV collagen (chapter 5). In children with hereditary jade, clinically manifested hematuuria, the collagen IV type collagen mutations are detected. The pathology of GBM (Alport syndrome, etc.) is established by an electron microscopic study of the kidney bioption (Fig. 1.5). Currently, genetic methods are used more often.

Figure 1.5. The wall of the Capillary of the Cluster is a glomerural filter (J.C.Jennet 1995). On the bottom there is a fenst endothelium, above it - GBM, on which regularly visible legs of the poverty (electron microscopy) are clearly visible.

Visceral epithelial cells, Poverty, support the architecture of the Gulk, prevent the passage of the protein into the urinary space, and also synthesize GBM. Long primary processes (Trabecules) are deployed from the body of the pecitis, the ends of which have "legs" attached to GBM. Small processes (pediculs) depart from large almost perpendicularly and covered the space of the capillary free from large processes (Fig. 1.6 a). A filtration membrane is stretched between the adjacent legs of the poverty - the slit diaphragm, which in recent decades is the subject of numerous studies (Fig. 1.6 b). Slitual diaphragms consist of non-protein nephritis, which is closely connected in structural and functional ratios with a plurality of other protein molecules: undercine, SD2AR, Alfa-Aktinin-4, etc.

BUT

1.6-Sure. The structure of the Podocyte (J.C.Jennet 1995). A - scanning electronogram. The legs of the noise are completely covered with GBM, as well as the legs of the noise between themselves form a network. B - between the legs of the podocytes is a slit diaphragm forming an ending filtering barrier.

Mesangium cells are determined as part of the glorula, the main function of which is to ensure the mechanical fixation of capillary loops. Mesangium cells have a contractile ability, affecting glomerular blood flow, and also possess phagocytic activity (Fig. 1.4-b).

Kidney Channels

The primary urine enters the proximal renal tubules and is subject to high-quality and quantitative changes by secretion and reabsorption of substances. Proximal Canal- The long segment of the nephron, at the beginning it is very curved, and when moving to a loop, it is straightened. The cells of the proximal canal (continued parietal epithelium capsule capsule of the Gulp) of the cylindrical shape, from the side of the lumen, covered with microwaves ("brush kaym"). Here there is an active reabsorption of many substances (glucose, amino acids, sodium ions, potassium, calcium and phosphates). In the proximal tubules, approximately 180 liters of gloming ultrafiltrate, and 65-80% of water and sodium are reabsorbated back. Thus, as a result, the volume of primary urine is significantly reduced without changing its concentration.

Loop Gennet. The direct part of the proximal tube, goes into a downward knee of loops Genla. The shape of epithelial cells becomes less elongated, the number of microvones decreases. The ascending loop area has a thin and thick part and ends in a dense spot. The main ion carrier of these cells - NKCC2.inhibited by furosemeid.

YuCSTAGLOMERULAR device (South) Includes 3 types of cells: the cells of the distal tubular epithelium on the skin adjacent to the flopper (dense spot), extragilomalular mesangium cells and granular cells in the walls of afferent arteriols that produce renin. (Fig.1.7).

Figure 1.7. Temperature Temporary Scheme (J.C.Jennet 1995)

Distal canal.Over the dense spot (Macula Densa) begins distal channel, which goes into a collecting tube. About 5% Na primary urine is absorbed in the distal tubules. The carrier is inhibited by diuretics from the group of thiazids.

Collective tubescontain two types of cells: the main ("light") and insertion ("dark"). As the cortical dialing of the tube into medullar, the number of insert cells is reduced. The main cells contain sodium channels whose work is inhibited by diuretics - amyloride, triamtenene. In insert cells, there are no Na + / k + -atphase, but contains n + -atphase. They are secreted by H + and reabsorption SL -. Thus, in collecting tubes, the final stage of the NaCl reverse absorption is carried out before the urine output from the kidneys.

Interstitial kidney cells. In the cortex layer of kidney of the interstitis, weakly is expressed, whereas in the brain layer it is more noticeable. The kidney cortical substance contains two types of interstitial cells - phagocyant and fibroblastic. Fibroblast-like interstitial cells produce erythropoietin. In the cerebral cereal, there are three types of cells. In the cytoplasm of cells of one of these types, small lipid cells serve as the initial material for the synthesis of prostaglandins are contained.

Physiology of kidneys

The kidneys provide the consistency of the medium necessary for the functioning of the cell cells. They regulate water salt balance, Acid-alkaline state, isolated nitrogen exchange and alien substances.