The nephron, whose structure directly depends on human health, is responsible for the work of the kidneys. The kidneys consist of several thousand such nephrons, thanks to them the urine formation, excretion of slags and purification of blood from harmful substances after processing of the received products are correctly performed in the body.
What is a nephron?
Nephron, whose structure and significance are very important for the human body, is a structural and functional unit within the kidney. Inside this structural element, urine is formed, which then exits the body through appropriate pathways.
Biologists say that within each kidney there are up to two million such nephrons, and each of them must be absolutely healthy so that the genitourinary system can fully fulfill its function. In case of damage to the kidney, nephrons can not be restored, they will be removed together with the newly formed urine.
Nephron: its structure, functional significance
The nephron is a shell for a small tangle, which consists of two walls and covers a small tangle of capillaries. The inner part of this shell is covered with epithelium, the special cells of which help to obtain additional protection. The space that is formed between the two layers can be transformed into a small hole and a channel.
This channel has a brush edge of small villi, just behind it begins a very narrow section of the hinge loop, which descends. The wall of the site consists of flat and small cells of the epithelium. In some cases, the compartment of the loop reaches the depth of the brain substance, and then turns to the crust of the kidney formations, which gradually grow into another segment of the nephron loop.
How is the nephron?
The structure of the renal nephron is very complex, until now the biologists around the world are struggling to recreate it in the form of an artificial formation suitable for transplantation. The loop appears mainly from the rising part, but can also include a delicate one. Once the loop is in the place where the tangle is located, it enters a curved small channel.
In the cells of the resulting formation there is no fleecy edge, however, a large number of mitochondria can be found here. The total area of the membrane can be increased because of the numerous folds that form as a result of the formation of a loop inside the individual nephron taken.
The scheme of the structure of the human nephron is quite complex, since it requires not only careful drawing, but also thorough knowledge of the subject. A person who is far from biology will find it rather difficult to portray it. The last area of the nephron is a shortened binder duct that emerges into the collecting tube.
The canal is formed in the cortical part of the kidney, with the help of storage tubes it passes through the "brain" of the cell. On average, the diameter of each shell is about 0.2 millimeters, but the maximum length of the nephron channel, recorded by scientists, is about 5 centimeters.
Kidney and nephron sections
The nephron, whose structure became known to scientists only after a number of experiments, is in each of the structural elements of the most important organ for the body - the kidneys. Specific features of the kidneys are such that it requires the existence of several sections of structural elements: a thin segment of the loop, distal and proximal.
All channels of the nephron in contact with the stacked cumulative tubes. With the development of the embryo, they randomly evolve, but to an already formed body according to its functions resemble the distal portion of the nephron. Detailed development process of the nephron scientists repeatedly reproduced in their labs for several years, but the original data were obtained only in the late XX century.
Types of nephrons in the kidneys of man
The scheme of the structure of the human nephron differs depending on the type. There are juxtammadullary, intracortical and super-official. The main difference between them is their location inside the kidney, the depth of the tubules and the location of the glomeruli, and also in the size of the coils themselves. In addition, scientists attach importance to the characteristics of loops and the duration of various segments of the nephron.
The super-formal type is a compound created from short loops, and juxtamadullar is from a long one. Such diversity, according to scientists, appears as a result of the need for nephrons to reach all parts of the kidney, including the one that lies below the cortical substance.
Parts of the nephron
Nephron, the structure and significance of which is well understood for the body, directly depends on the tubule contained in it. It is the latter that is responsible for the permanent functional work. All substances that are present inside the nephrons, are responsible for the safety of certain types of kidney tangles.
Inside the cortical substance, you can find a large number of connective elements, specific subunits of canals, renal glomeruli. From the fact whether they are properly placed inside the nephron and the kidney as a whole, the work of the entire internal organ will depend. First of all, this will influence the uniform distribution of urine, and only then on its correct withdrawal from the body.
Nephrons as filters
The structure of the nephron at first glance looks like one large filter, but it has a number of features. In the middle of the XIX century, scientists assumed that the filtration of liquids in the body precedes the stage of urine formation, after a hundred years it was scientifically proven. With the help of a special manipulator, scientists managed to get the internal fluid from the glomerular shell, and then conduct its thorough analysis.
It turned out that the shell is a kind of filter, through which the water and all molecules that form the blood plasma are purified. The membrane, through which all liquids are filtered, is based on three elements: podocytes, endothelial cells, and a basal membrane is also used. With their help, the fluid that must be removed from the body falls into the ball of the nephron.
Nephron internals: cells and membrane
The structure of the human nephron should be considered taking into account what is contained in the glomerulus of the nephron. First, we are talking about endothelial cells, with the help of which a layer is formed that prevents the ingestion of protein and blood inside the particles. Plasma and water pass further, freely enter the basal membrane.
The membrane is a thin layer that separates the endothelium (epithelium) from a connective tissue. The average thickness of the membrane in the human body is 325 nm, although thicker and finer variants may occur. The membrane consists of a nodular and two peripheral layers that block the way for large molecules.
Podocytes in the nephron
Processes of podocytes are separated from each other by shield membranes, on which the nephron itself depends, the structure of the structural element of the kidney and its operability. Thanks to him it is determined the size of substances that need to be filtered out. Epithelial cells have small processes, due to which they connect to the basal membrane.
The structure and functions of the nephron are such that, collectively, all its elements do not pass molecules larger than 6 nm in diameter and produce a filtration of smaller molecules that must be removed from the body. The protein can not pass through the existing filter due to the special elements of the membrane and the molecules with a negative charge.
Features of the renal filter
The nephron, the structure of which requires careful study by scholars seeking to recreate the kidney with the help of modern technology, carries a negative charge, which forms the limit for filtering proteins. The size of the charge depends on the size of the filter, and in fact itself a component of the glomerular substances depends on the quality of the basal membrane and the epithelial covering.
The features of the barrier used in the form of a filter can be realized in a variety of variations, each nephron possesses individual parameters. If there are no violations in the work of nephrons, then in the primary urine there will be only traces of proteins that are inherent in blood plasma. Especially large molecules can also penetrate through the pores, but in this case everything will depend on their parameters, as well as on the localization of the molecule and its contact with the forms that take pores.
Nephrons are not able to regenerate, so if the kidneys are damaged or if there are any diseases, their number gradually begins to decrease. The same happens for natural reasons, when the body begins to age. Restoration of nephrons is one of the most important tasks, over which scientists and biologists of the whole world work.