The main function of the kidneys is. The role of the kidneys in the life support of the human body and their functions. What functions do the kidneys perform?

Kidneys are important organs, problems with the functioning of which negatively affect the condition of the body. With diseases of the urinary system, health worsens, toxins accumulate, harmful salts, causeless weakness appears, immunity decreases.

What are the functions of kidneys in the body? How to protect important organs from negative impact? How much liquid do you need to drink per day to actively cleanse yourself of waste products? What signs indicate the development of renal pathologies? The answers are in the article.

Kidney structure

Basic information:

paired organs, bean-shaped;
in case of kidney failure, forced blood purification is required using a hemodialysis machine, otherwise all toxins will remain in the body, and after a while the patient will die;
the organs are located in the lumbar region, the left one is slightly higher: the liver is located above the right one;
dimensions - 10-12 cm, the right organ is slightly smaller;
on the outside there is a protective shell, inside there is a system for accumulating and removing liquid;
the thickness of the parenchyma, limited by the shell and the connecting base, is 15-25 mm;
the main structural unit is the nephron, the amount in a healthy body is 1-1.3 million. Urine is formed inside the nephron. Depending on functionality and structure, three types of nephrons are distinguished;
renal tissue has a homogeneous structure, foreign inclusions (sand, stones, tumors) are normally absent;
The renal artery delivers blood to the kidney; inside the organ, the vessel branches into arterioles that fill each glomerulus with blood. Constant pressure maintains an optimal ratio of arterioles: the afferent arteriole is twice as narrow as the afferent arteriole;
blood pressure fluctuations range from 100 to 150 mm Hg. Art. does not affect blood flow in renal tissue. With severe stress, pathological processes, blood loss, a decrease in blood flow is observed;
The large renal calyces form the renal pelvis, connected through the ureters to the bladder.

Urine formation

The process consists of three stages. Violation of the filtration function, damage to the glomeruli and tubules interferes with the process, provokes fluid stagnation, and leads to the accumulation of toxins.

Main stages:

filtration through three layers of glomerular filter;
accumulation of primary urine in collecting barrels and tubules;
tubular secretion - transporting waste substances from the blood into the urine.

The volume and quality of urine excreted throughout the day is regulated by hormones:

adrenaline - reduces urine formation;
Aldosterone is secreted by the adrenal cortex. Excess of the hormone causes heart failure, edema, excess - dehydration, decreased blood volume;
estradiol regulates phosphorus-calcium metabolism;
Vasopressin is responsible for the absorption of water by the kidneys. The hormone is produced by the hypothalamus. When this section is damaged, the volume of urine increases sharply - up to five liters;
parathyroid hormone is responsible for removing various salts from the body.

Note! Kidney function is regulated not only by substances produced by the adrenal glands, thyroid gland, hypothalamus, but also sympathetic fibers and the vagus nerve.

Functions of paired organs

The main function of the kidneys is that the organs pump all the blood through tiny filters, purify the liquid from microbes, toxins, waste, poisons, and other harmful components. The filtration capacity of the kidneys is amazing - up to two hundred liters of urine per day! Thanks to the kidneys, the body constantly receives “clean” blood. Waste products and decay products are excreted in urine through the urethra (urethra) naturally.

What functions do the kidneys perform?

excretory kidney function. Removing urea, breakdown products, poisons, creatinine, ammonia, amino acids, glucose, salts from the body. Violation of excretory function leads to intoxication and deterioration of well-being;
protective. Important organs filter and neutralize dangerous substances that enter the body: nicotine, alcohol, drug components;
metabolic. Participate in carbohydrate, lipid, protein metabolism;
homeostatic. Regulate the ionic composition of the intercellular substance and blood, maintain a constant volume of fluid in the body;
endocrine kidney function. Nephrons are involved in the synthesis of important hormones and substances: prostaglandins (regulate blood pressure), calcitrol (regulates calcium metabolism), erythropoietin (stimulates hematopoiesis), renin (maintains optimal blood circulation).

It is difficult to overestimate the importance of the kidneys. Most people do not think about how important the work of the bean-shaped organs is until diseases of an inflammatory and non-inflammatory nature develop. Damage to the kidney tissue, problems with the production and excretion of urine negatively affect various departments body.

Symptoms of the development of renal pathologies

The early stages are often virtually asymptomatic. People often do not pay attention to mild discomfort in the lumbar region and believe that their back hurts from overexertion. Only with strong pain syndrome, accidental detection of urinary tract diseases due to poor urine tests, patients visit a urologist.

Unfortunately, based on the results of urine and blood tests and x-rays, the doctor often reveals a chronic form of the pathology. In advanced cases, nephrosis requires long-term and often costly treatment.

Go to the address and read information about how to prepare for retrograde urography and how the procedure works.

It is important to know the main signs of kidney problems:

in the morning, swelling is noticeable under the eyes and on the legs, which after a couple of hours disappears as imperceptibly as it appeared;
often rises blood pressure. Violation of indicators is a sign not only of hypertension, but also of nephritis, atherosclerosis, diabetes;
problems urinating: passing more or less urine than usual, although drinking regime approximately the same;
discomfort in the lumbar region. If, then discomfort is heard from one side or the other, sometimes on both sides of the spine, but not in the central part (along the vertical axis);
the shade or transparency of urine changes;
“shots” are periodically heard in the lumbar region, more often on one side. This sign indicates an active inflammatory process or movement of stones through the ureters;
causeless weakness, lethargy, drowsiness, combined with slight discomfort in the lumbar area and high blood pressure should prompt the idea of visiting a urologist. With kidney pathologies, toxins accumulate in the body, hence the deterioration of the general condition.

Important! If one or more symptoms appear, it is important to immediately visit a nephrologist or urologist, take a urine and blood test, and do an ultrasound of the kidneys. Often, negative symptoms are practically absent, but the acidity of the urine is higher or lower than normal, red blood cells and protein appear in the urine, the level of leukocytes increases, and other indicators worsen.

What is harmful to the kidneys

Pathologies of important organs develop under the influence of negative factors:

hypothermia, wet feet;
alcohol abuse;
heat: kidneys work with increased load, actively process increased volume fluid consumed;
drafts, cold wind;
lack of physical activity, causing stagnation of blood and urine;
crowded bladder: the optimal number of urinations is 5-6 times per day. When urine stagnates, harmful microorganisms actively multiply;
sudden weight loss often provokes prolapse of the kidney due to a decrease in the volume of the protective fat layer surrounding the bean-shaped organ;
frequent use of antibiotics and other potent drugs;
eating too sweet or salty foods, smoked foods, spicy, fried foods negatively affects the condition of nephrons, tubules, filtering glomeruli;
carbonated drinks with artificial colors, flavors, and sweeteners do not benefit the kidneys;
mineral water with gas, high salt content creates a load on the kidneys. It is important to release the gas, slightly warm the healing liquid, and only after these manipulations consume the liquid. Medicinal mineral waters are only allowed to be drunk in courses, taking into account the nature of the disease and the composition of the salts;
serious physical activity, overwork, heavy lifting, overload during sports competitions;
inflammatory processes in various parts of the body. Pathogenic microorganisms enter the renal tubules with the blood, possibly infecting important organs.

How to reduce the risk of disease

prevention of hypothermia;
drinking clean, “soft” water;
refusal of frequent consumption of sour juices, citrus fruits, tomatoes;
It’s good to drink weaker drinks more often green tea, rosehip decoction, infusion corn silk, bearberry, parsley;
The buds of melons and watermelons are washed well. An important point - melons must contain a minimum amount of nitrates;
table mineral water is good for the body, but in reasonable quantities. The frequency of use and daily dosage is suggested by the urologist for a particular patient;
Do not drink strong alcohol, beer, wine. Carbonated low-alcohol drinks with dozens of chemical compounds are especially harmful;
You should not eat stale foods, overload your body with “heavy” foods, or overuse spices and hot spices;
it is important to limit the consumption of salt, which provokes the accumulation of fluid in the body, swelling, and increased stress on the urinary tract;
correct drinking regime - up to two liters of water per day. This should become the norm for every day, otherwise, over time, toxins will accumulate if the kidneys are not flushed as expected;
Do not get carried away with offal, veal, mackerel, cod, beef, sorrel, spinach. Strong coffee, chocolate, beer, legumes are items containing purines and oxalates. Frequent consumption of these types of food provokes active deposition of salts, leading to urolithiasis and gout - joint diseases.

Proper kidney function is vital for the body. In patients suffering from severe renal failure, the quality of life is significantly reduced and the immune system weakens. Knowledge about the structure and functioning of important organs helps to understand why you need to protect your kidneys and how to prevent pathologies of infectious and non-infectious nature.

Video - an anatomy lesson that explains the functions of the urinary system, the structure of the kidneys and the formation of urine:

Bud- paired organ. The function in the body is multifaceted. The structure distinguishes between the cortex and medulla. At the upper pole of each kidneys There is a small endocrine gland - the adrenal gland. Kidney tissue consists of cells called nephrons, their number is colossal - millions. It is in these cells that urine is formed. Initially, plasma and water are filtered through the glomeruli. Then, as a result of reverse reabsorption, absorption of useful substances occurs, and as a result of tubular secretion, unnecessary components and products enter the urine and are excreted from the body.

The amount of urine produced and its further excretion (diuresis) depends on the activity of hormones that regulate this process. Aldosterone affects the retention of sodium in the body, and, consequently, water. Adrenaline (the main stress hormone) reduces urine production. Vasopressin, which is produced in the hypothalamus, regulates absorption processes in the kidneys. When the activity of this brain formation is disrupted, the amount of urine increases sharply. Besides hormonal regulation, activity kidney connected to the vagus nerve.

The role of the kidneys in the human body :

excretory Formation and excretion of urine, and with it substances unnecessary to the body (decomposition products, toxins, etc.);

homeostatic, i.e. aimed at maintaining the internal constancy of the body;

metabolic, i.e. active participation in various metabolic processes in the body;

endocrine, i.e. the production of various substances: calcitrol, whose function is to regulate calcium metabolism, renin - responsible for the volume of circulating blood, prostaglandins, on which blood pressure depends, erythropoietin - responsible for homepoiesis, i.e. process of hematopoiesis in red bone marrow.

For work kidney In standard mode, sufficient fluid intake is required. Alcohol, carbonated drinks, coffee negatively affect work kidney. Hypertension, obesity, availability various diseases also not promising for kidney nothing good. Hypothermia can cause kidney diseases inflammatory in nature. Physical inactivity and metabolic disorders contribute to the formation of kidneys stones. Kidney diseases very serious. The most dangerous complication renal pathology Anuria occurs when urine excretion stops completely and the body becomes poisoned with its own decay products.

During treatment renal pathology Nutrition plays an important role; table No. 7 is assigned, the basis of which is limiting the amount of salt.

Almost all functions of the kidneys in our body are irreplaceable and vital, and with various disorders they normal operation, most organs and systems of the human body are affected. Thanks to the activity of the kidneys, the constancy of the internal environment of the body (homeostasis) is maintained. When any irreversible pathological process occurs in a given organ, the consequences of the disease become extremely severe and sometimes fatal.

If we consider the question of what function the kidneys perform in human body and what life support processes are controlled, first of all it is necessary to become familiar with the structural features of all components of this organ (especially at the cellular level).

Anatomical and physiological structure of the organ and its significance for the body

Normally, a person from birth has two kidneys, which are located symmetrically from spinal column in his thoracolumbar region. If abnormalities occur in development, a child may be born with three or, conversely, one kidney.

The organ is bean-shaped and is covered on the outside by a dense capsule consisting of a connective tissue component. The outer layer is called the renal cortex and occupies a smaller volume. Inner layer is called the “medullary substance”, its basis is parenchymal tissue and stroma, which is abundantly penetrated by renal vessels and nerve fibers.

If we analyze the process of urine accumulation, then in a simplified version it looks like this: small cups merge with each other, forming large cups, and they, in turn, form a system of pelvises and open into the lumen of the ureter.

The morphofunctional unit of the kidney is the nephron, which is responsible for most of the functions of the kidneys in the human body. All nephrons are closely interconnected and represent a complex “uninterrupted” mechanism.

Their structure includes the following structures:

glomerular apparatus (Malpighian corpuscle), located in the thickness of the cortex, the main function of which is to filter incoming blood;
a capsule that covers the outside of the glomerulus and acts as a “filter” through which the blood is cleansed of any kind of toxins and metabolic products;
a complex system of convoluted tubules that interconnect and allow filtered fluid to be reabsorbed.

The tissues of each kidney contain at least 1 million actively functioning nephrons

The work of all components of the nephron sequentially goes through three phases:

Blood plasma filtration with the formation of primary urine (occurs in the glomeruli). During the day, approximately 200 liters of such urine are produced through the kidneys, which in its composition is close to human plasma.
Reabsorption or reabsorption process necessary to prevent the body from losing it in urine necessary substances(this occurs in the tubular system). Thus, vitamins, important salts, glucose, amino acids and others are retained.
Secretion, in which all toxic products, unnecessary ions and other substances retained by the renal filter enter the final urinary sediment and are excreted irrevocably.

The renal apparatus operates in a constant mode, where one phase of the process smoothly replaces another

When it comes to the structure and function of the kidneys, it is impossible not to mention that at the upper pole of this organ there are special paired formations, which are called adrenal glands. Despite the fact that they are small in volume, their functionality is unique and extremely necessary.

The adrenal glands consist of parenchyma and belong to a paired endocrine organ, which determines their main purpose in the human body. Suppression of their work leads to a number of serious disorders that require immediate medical intervention. Among the most frequent illnesses problems that a specialist has to deal with include such a pathology as hypofunction of the adrenal glands (the production of certain hormones is sharply inhibited).

The adrenal glands are a vital organ for humans

Functions of the kidneys and adrenal glands

The main function for which the kidneys are responsible is called excretory - this is the ability to form and, subsequently, excrete final product exchange, namely urine. In the medical literature you can come across the term “excretory” function, which is synonymous with the previous process.

The excretory (or excretory) activity of the kidneys includes filtration and secretory functions, which were described above. Their main task is to remove waste and toxins from the body through urinary sediment.

The final urine contains waste products that are “unnecessary” for the body.

An equally important function of the kidneys is their ability to synthesize hormonal substances. The endocrine function of the organ is associated with the entry into the blood of hormones such as:

renin (it is responsible for the balance of water in the body, prevents its excessive secretion and controls the constancy of blood volume in the circulatory system);
erythropoietin (a substance that stimulates the production of red blood cells in bone marrow cells);
prostaglandins (control blood pressure levels).

The metabolic function of an organ is that in its tissues a number of biological substances are synthesized or converted into active forms (for example, the inactive form of vitamin D in the kidneys changes its structure and becomes more active).

The kidneys are able to maintain the balance of the ionic composition of the plasma and maintain a constant osmotic pressure in the body.

The concentration function of the renal apparatus is that it is capable of concentrating urine, namely, increasing the release of dissolved substrates with it. When this function fails, then, on the contrary, the release of water, not substances, increases. Thus, the functional capacity of the kidneys is reflected.

The most important functions of the adrenal glands are reflected in the following:

They are directly involved in many metabolic and metabolic processes.
They produce a number of vital hormonal substances that affect the functioning of individual body systems (mainly the functions of the adrenal cortex).
They determine the behavior and reaction of the human body to stressful situations.
Thanks to the adrenal glands, the body's response to irritating influences from the outside is formed.

The main function of the adrenal glands is the synthesis of hormonal substances

Functional impairment

Whole books have been written about the possible factors and causes of dysfunction in the kidneys; there are many syndromes, diseases and pathological conditions, which are a consequence of a violation of one or another organ function. All of them are undoubtedly very important, but we will try to focus on the most important points.

Main Factors

When it comes to etiological factors, that is, those reasons that led to kidney disease, the following groups must be distinguished among them.

Prerenal mechanisms are caused by processes that indirectly affect the functional activity of the organ. These include:

various kinds mental states, work disorders nervous system, as a result of which the development of reflex urinary retention is possible, up to its complete absence;
pathology of an endocrine nature, leading to a disruption in the synthesis of hormonal substances that can affect the functioning of the kidney;
disturbance of the blood supply to the organ during general hypotensive processes (for example, during collapse) or during a hypertensive crisis.

Renal mechanisms involve direct damage to kidney tissue (inflammatory or autoimmune diseases, thrombosis, aneurysm or atherosclerosis of the renal vessels and others).

Postrenal damage mechanisms are triggered when obstacles arise in the way of the natural outflow of urine (blockage of the lumen of the ureter with a stone, compression by a tumor process, and others).

Main types of acute renal failure

Development mechanisms

When exposed to any of the above factors, disturbances occur associated with changes in the processes of filtration, reabsorption or excretion.

Changes in filtration may appear:

a decrease in the volume of filtered plasma in the glomerular apparatus (in hypotonic conditions, necrotic or sclerotic processes in glomerular tissues);
an increase in the volume of filtered plasma (hypertension, inflammatory processes leading to increased permeability of the glomerular membrane).

Changes in reabsorption are characterized by a slowdown in this process, which is most often associated with genetic abnormalities at the enzyme level.

Impaired excretion manifests itself in a delay toxic substances in the body and their adverse effects on the entire body, possibly with glomerulonephritis of various etiologies, ischemic diseases kidneys and others.

Main manifestations

Kidney function is assessed based on the following characteristics:

Diuresis indicators, that is, the volume of urine excreted during the day. Normally, a person excretes slightly less urine than he drinks fluids, and with pathology, the development of polyuria, oliguria or anuria is likely.
Density of urinary sediment (normally ranges from 1008 to 1028). In pathology, they speak of hypersthenuria, hyposthenuria or isosthenuria.
The components that make up urine and their quantitative ratio (we are talking about leukocytes, erythrocytes, protein, casts and others).

Kidney function is assessed using a number of diagnostic criteria for urinary sediment.

Renal failure is a complex of symptoms and syndromes, the development of which is caused by a decrease or complete cessation of urine output. There is an accumulation of toxic metabolic products that “poison” the body.

The acute process develops literally within a few hours, and its main symptom is the progression and disruption of all vital processes.

Chronic failure can develop over many years; this is due to the gradual death of nephrons.

Treatment

To restore the impaired functions of the renal apparatus, they resort to etiotropic and pathogenetic therapy, but do not forget about symptomatic treatment.

Etiotropic therapy includes the complete elimination or maximum correction of all causes that became the source of the disease.

Principles pathogenetic treatment consist in blocking certain parts of the disease, which allows for the restoration of kidney function and their natural functioning. For this purpose, agents are used that can suppress the immune system, or, conversely, stimulate the body’s protective properties, hemodialysis procedures, and others are performed.

Conducting hemodialysis blood purification sessions helps the human body fight the toxic effects of harmful substances and toxins

Symptomatic therapy includes a huge range of medications that restore and correct the consequences of improper kidney function (hypotensives, diuretics, and others).

Conclusion

Unfortunately, kidney pathology is very common and affects the working population among both women and men. If functional disorders are not diagnosed in time, then there is a risk of a protracted course of the process, which often becomes the cause of disability.

Kidneys are one of the vital organs in the human body; they perform more than one function. Metabolic, protective, excretory, homeostatic and endocrine are the functions of the kidneys. U healthy person a paired number of kidneys, although there are cases when, under the threat of life, one of the kidneys is removed, then throughout the patient’s life, his health is at risk.

Throughout the day, the kidneys pump through themselves all the blood that is in the body. In one minute, one liter of blood passes through the kidneys, from this blood the kidneys select all the harmful substances that should go into the blood plasma, after which the harmful microbes enter the ureter, and only after that they end up in the bladder. When a person has a bowel movement, harmful substances are eliminated from the human body along with urine.

Thanks to the valve located in the ureter, toxins cannot return back because it opens only in one direction. Throughout the day, the kidneys pump about 200 liters of blood through themselves, thereby removing toxins from the body and making the blood sterilely clean. And this, you see, is a very important function for human health and life, which is the main one.

Synthesis also takes place in the kidneys essential hormones, such as renin, erythropoietin and prostaglandin. Water in the human body is retained due to the hormone renin, prostaglandin regulates blood pressure, and the number of red blood cells is regulated due to erythropoietin.

The kidneys synthesize various vitamins and microelements, without which human life is not possible. Thanks to the ability of the kidneys to synthesize, the body maintains a balance of carbohydrates, proteins and lipids.

To summarize, we can say that the kidneys perform functions in the body without which further human life is not possible. Therefore, everyone should take care of their kidneys and the health of the entire body.

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Kidneys are of great importance in the human body. They perform a number of vital functions. Humans normally have two organs. Consequently, there are types of kidneys - right and left. A person can live with one of them, but the body’s vital activity will be under constant threat, because its resistance to infections will decrease tenfold.

The kidney is a paired organ. This means that a person normally has two of them. Each organ is bean-shaped and belongs to the urinary system. However, the main functions of the kidneys are not limited to excretory function.

The organs are located in the lumbar region on the right and left between the thoracic and lumbar regions spine. In this case, the location of the right kidney is slightly lower than the left one. This is explained by the fact that the liver is located above it, which prevents the kidney from moving upward.

The kidneys are approximately the same in size: they have a length of 11.5 to 12.5 cm, a thickness of 3 to 4 cm, a width of 5 to 6 cm each and a weight of 120 to 200 g. The right one, as a rule, is slightly smaller in size .

What is the physiology of the kidneys? The outside of the organ is covered by a capsule that reliably protects it. In addition, each kidney consists of a system whose functions are limited to the accumulation and removal of urine, as well as parenchyma. The parenchyma consists cortex(its outer layer) and the medulla (its inner layer). The urine storage system consists of the small renal calyces. The minor calyces fuse to form the larger renal calyces. The latter also connect and together form the renal pelvis. And the pelvis connects to the ureter. In humans, accordingly, there are two ureters that enter the bladder.

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In addition, the organs are equipped with a structural and functional unit called the nephron. The nephron is considered the most important unit of the kidney. Each organ contains more than one nephron, but has approximately 1 million of them. Each nephron is responsible for the functioning of the kidneys in the human body. It is the nephron that is responsible for the process of urine formation. Most nephrons are located in the renal cortex.

Each structural and functional unit, the nephron, represents an entire system. This system consists of the Shumlyansky-Bowman capsule, the glomerulus and intersecting tubules. Each glomerulus is a system of capillaries that supplies the kidney with blood. The loops of these capillaries are located in the cavity of the capsule, which is located between its two walls. The cavity of the capsule passes into the cavity of the tubules. These tubules form a loop that penetrates from the cortex into the medulla. The latter contains nephron and excretory tubules. The second tubules drain urine into the calyces.

The medulla forms pyramids with vertices. Each apex of the pyramid ends with papillae, which enter the cavity of the minor calyx. In the area of the papillae, all excretory tubules unite.

The structural and functional unit of the kidney, the nephron, ensures the proper functioning of the organs. If the nephron were absent, the organs would not be able to perform their functions.

The physiology of the kidneys includes not only the nephron, but also other systems that ensure the functioning of the organs. So, the renal arteries depart from the aorta. Thanks to them, blood supply to the kidney occurs. Nervous regulation The functions of the organs are carried out with the help of nerves that penetrate from the celiac plexus directly into the kidneys. The sensitivity of the kidney capsule is also possible thanks to the nerves.

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To understand how the kidneys work, you first need to understand what functions are assigned to them. These include the following:

excretory, or excretory;
osmoregulatory;
ion-regulating;
intrasecretory, or endocrine;
metabolic;
hematopoietic (directly involved in this process);
renal concentration function.

During the day they pump the entire volume of blood. The number of repetitions of this process is enormous. About 1 liter of blood is pumped in 1 minute. In this case, the organs select from the pumped blood all decay products, waste, toxins, microbes and other substances harmful to the human body. Then all these substances enter the blood plasma. Next, all this is sent to the ureters, and from there to the bladder. After this, harmful substances leave the human body when the bladder is emptied.

Once toxins enter the ureters, they can no longer return to the body. Thanks to a special valve located in the organs, the re-entry of toxins into the body is absolutely excluded. This is made possible by the fact that the valve opens in only one direction.

Thus, pumping over 200 liters of blood per day, the organs guard its purity. Blood becomes clean from being clogged with toxins and microbes. This is extremely important because blood bathes every cell in the human body, so it is vital that it be cleansed.

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So, the main function that the organs perform is excretory. It is also called excretory. The excretory function of the kidneys is responsible for filtration and secretion. These processes occur with the participation of the glomerulus and tubules. In particular, the glomerulus carries out the filtration process, and the tubules carry out the processes of secretion and reabsorption of substances that need to be removed from the body. The excretory function of the kidneys is very important, since it is responsible for the formation of urine and ensures its normal excretion (excretion) from the body.

Endocrine function consists of the synthesis of certain hormones. First of all, this concerns renin, thanks to which water is retained in the human body and the volume of circulating blood is regulated. The hormone erythropoietin is also important, which stimulates the creation of red blood cells in the bone marrow. And finally, the organs synthesize prostaglandins. These are substances that regulate blood pressure.

The metabolic function lies in the fact that it is in the kidneys that microelements and substances vital for the functioning of the body are synthesized and transformed into even more important ones. For example, vitamin D is converted to D3. Both vitamins are extremely important for humans, but vitamin D3 is a more active form of vitamin D. In addition, thanks to this function, the body maintains an optimal balance of proteins, carbohydrates and lipids.

The ion-regulating function implies the regulation of the acid-base balance, for which these organs are also responsible. Thanks to them, the acidic and alkaline components of the blood plasma are maintained in a stable and optimal ratio. Both organs release, if necessary, excess bicarbonate or hydrogen, due to which this balance is maintained.

The osmoregulatory function is to maintain the concentration of osmotically active blood substances under different water conditions to which the body may be exposed.

Hematopoietic function means the participation of both organs in the process of hematopoiesis and purification of the blood from toxins, microbes, harmful bacteria and waste.

The concentrating function of the kidneys means that they concentrate and dilute urine by releasing water and dissolved substances (primarily urea). The organs must do this almost independently of each other. When urine is diluted, more water is released rather than solutes. On the contrary, through concentration, a larger volume of solutes is released rather than water. The concentration function of the kidneys is extremely important for the functioning of the entire human body.

Thus, it becomes clear that the importance of the kidneys and their role for the body is so great that it is difficult to overestimate them.

That is why it is so important to pay due attention to the slightest disturbance in the functioning of these organs and consult a doctor. Since many processes in the body depend on the work of these organs, restoring kidney function becomes an extremely important measure.

Almost all functions of the kidneys in our body are irreplaceable and vital, and with various violations of their normal functioning, most organs and systems of the human body suffer. Thanks to the activity of the kidneys, the constancy of the internal environment of the body (homeostasis) is maintained. When any irreversible pathological process occurs in a given organ, the consequences of the disease become extremely severe and sometimes fatal.

If we consider the question of what function the kidneys perform in the human body and what life support processes they control, first of all it is necessary to become familiar with the structural features of all components of this organ (especially at the cellular level).

Normally, a person from birth has two kidneys, which are located symmetrically from the spinal column in his thoracolumbar region. If abnormalities occur in development, a child may be born with three or, conversely, one kidney.

The organ is bean-shaped and is covered on the outside by a dense capsule consisting of a connective tissue component. The outer layer is called the renal cortex and occupies a smaller volume. The inner layer is called the “medullary substance”; it is based on parenchymal tissue and stroma, which is abundantly penetrated by renal vessels and nerve fibers.

Their structure includes the following structures:

glomerular apparatus (Malpighian corpuscle), located in the thickness of the cortex, the main function of which is to filter incoming blood;
a capsule that covers the outside of the glomerulus and acts as a “filter” through which the blood is cleansed of any kind of toxins and metabolic products;
a complex system of convoluted tubules that interconnect and allow filtered fluid to be reabsorbed.

The tissues of each kidney contain at least 1 million actively functioning nephrons

The work of all components of the nephron sequentially goes through three phases:

Filtration of blood plasma with the formation of primary urine (occurs in the glomeruli). During the day, approximately 200 liters of such urine are produced through the kidneys, which in its composition is close to human plasma.
Reabsorption or the process of reverse absorption is necessary so that the body does not lose necessary substances in the urine (this happens in the tubular system). Thus, vitamins, important salts, glucose, amino acids and others are retained.
Secretion, in which all toxic products, unnecessary ions and other substances retained by the renal filter enter the final urinary sediment and are excreted irrevocably.

The renal apparatus operates in a constant mode, where one phase of the process smoothly replaces another

Adrenal glands

The adrenal glands consist of parenchyma and belong to a paired endocrine organ, which determines their main purpose in the human body. Suppression of their work leads to a number of serious disorders that require immediate medical intervention. Among the most common diseases that a specialist has to deal with are pathologies such as adrenal hypofunction (the production of certain hormones is sharply inhibited).

The adrenal glands are a vital organ for humans

Functions of the kidneys and adrenal glands

The main function for which the kidneys are responsible is called excretory - this is the ability to form and, subsequently, excrete the final product of metabolism, namely urine. In the medical literature you can come across the term “excretory” function, which is synonymous with the previous process.

The final urine contains waste products that are “unnecessary” for the body.

An equally important function of the kidneys is their ability to synthesize hormonal substances. The endocrine function of the organ is associated with the entry into the blood of hormones such as:

renin (it is responsible for the balance of water in the body, prevents its excessive secretion and controls the constancy of blood volume in the circulatory system);
erythropoietin (a substance that stimulates the production of red blood cells in bone marrow cells);
prostaglandins (control blood pressure levels).

The kidneys are able to maintain the balance of the ionic composition of the plasma and maintain a constant osmotic pressure in the body.

The most important functions of the adrenal glands are reflected in the following:

They are directly involved in many metabolic and metabolic processes.
They produce a number of vital hormonal substances that affect the functioning of individual body systems (mainly the functions of the adrenal cortex).
They determine the behavior and reaction of the human body to stressful situations.
Thanks to the adrenal glands, the body's response to irritating influences from the outside is formed.

The main function of the adrenal glands is the synthesis of hormonal substances

Functional impairment

Entire books have been written about the possible factors and causes of dysfunction in the functioning of the kidneys; there are many syndromes, diseases and pathological conditions that are a consequence of a violation of one or another function of the organ. All of them are undoubtedly very important, but we will try to focus on the most important points.

When it comes to etiological factors, that is, those reasons that led to kidney disease, the following groups must be distinguished among them.

Prerenal mechanisms are caused by processes that indirectly affect the functional activity of the organ. These include:

various types of mental states, disorders in the functioning of the nervous system, as a result of which the development of reflex urinary retention is possible, up to its complete absence;
pathology of an endocrine nature, leading to a disruption in the synthesis of hormonal substances that can affect the functioning of the kidney;
disturbance of the blood supply to the organ during general hypotensive processes (for example, during collapse) or during a hypertensive crisis.

Renal mechanisms involve direct damage to the kidney tissue (inflammatory or autoimmune diseases, thrombosis, aneurysm or atherosclerosis of the renal vessels, and others).

Main types of acute renal failure

Development mechanisms

When exposed to any of the above factors, disturbances occur associated with changes in the processes of filtration, reabsorption or excretion.

Changes in filtration may appear:

a decrease in the volume of filtered plasma in the glomerular apparatus (in hypotonic conditions, necrotic or sclerotic processes in glomerular tissues);
an increase in the volume of filtered plasma (hypertension, inflammatory processes leading to increased permeability of the glomerular membrane).

Changes in reabsorption are characterized by a slowdown in this process, which is most often associated with genetic abnormalities at the enzyme level.

Impaired excretion manifests itself in the retention of toxic substances in the body and their adverse effects on the entire body, possibly with glomerulonephritis of various etiologies, ischemic kidney diseases and others.

Kidney function is assessed based on the following characteristics:

Diuresis indicators, that is, the volume of urine excreted during the day. Normally, a person excretes slightly less urine than he drinks fluids, and with pathology, the development of polyuria, oliguria or anuria is likely.
Density of urinary sediment (normally ranges from 1008 to 1028). In pathology, they speak of hypersthenuria, hyposthenuria or isosthenuria.
The components that make up urine and their quantitative ratio (we are talking about leukocytes, erythrocytes, protein, casts and others).

Kidney function is assessed using a number of diagnostic criteria for urinary sediment.

The acute process develops literally within a few hours, and its main symptom is the progression and disruption of all vital processes.

Chronic failure can develop over many years; this is due to the gradual death of nephrons.

To restore the impaired functions of the renal apparatus, they resort to etiotropic and pathogenetic therapy, but do not forget about symptomatic treatment.

Etiotropic therapy includes the complete elimination or maximum correction of all causes that became the source of the disease.

The principles of pathogenetic treatment consist in blocking certain parts of the disease, which allows the restoration of kidney function and their natural functioning to begin. For this purpose, agents are used that can suppress the immune system, or, conversely, stimulate the body’s protective properties, hemodialysis procedures, and others are performed.

Conducting hemodialysis blood purification sessions helps the human body fight the toxic effects of harmful substances and toxins

Symptomatic therapy includes a huge range of medications that restore and correct the consequences of improper kidney function (hypotensives, diuretics, and others).

One of the important filtration organs in the human body is the kidneys. This paired organ is located in the retroperitoneal space, namely on the posterior surface abdominal cavity in the lumbar region on both sides of the spine. The right organ is anatomically located slightly lower than the left. Many of us believe that the only function of the kidney is to produce and excrete urine. However, in addition to the excretory function, the kidneys have many other tasks. In our article we will take a closer look at what the kidneys do.

Each kidney is surrounded by a membrane of connective and fatty tissue. Normally, the dimensions of the organ are as follows: width - no more than 60 mm, length - approximately 10-12 cm, thickness - no more than 4 cm. The weight of one kidney reaches 200 g, which is half a percent of the total weight of a person. In this case, the organ consumes oxygen in a volume of 10% of the total oxygen requirement of the body.

Despite the fact that normally there should be two kidneys, a person can live with one organ. Often one or even three kidneys are present from birth. If, after the loss of one organ, the second copes with double the assigned load, then the person can fully exist, but he needs to beware of infections and heavy physical exertion.

Nephrons, the main structural unit of the organ, are responsible for the functioning of the kidneys. Each kidney has about a million nephrons. They are responsible for the production of urine. To understand what function the kidneys perform, it is necessary to understand the structure of the nephron. Each structural unit contains a body with a capillary glomerulus inside, surrounded by a capsule, which consists of two layers. The inner layer consists of epithelial cells, and the outer layer consists of tubules and membrane.

Various functions of the human kidneys are realized due to the fact that nephrons are three types depending on the structure of their tubules and location:

Intracortical.
Superficial.
Juxtamedullary.

The main artery is responsible for transporting blood to the organ, which inside the kidney is divided into arterioles, each of which brings blood to the glomerulus. There is also an arteriole that drains blood from the glomerulus. Its diameter is smaller than that of the afferent arteriole. Thanks to this, the necessary pressure is constantly maintained inside the glomerulus.

There is constant constant blood flow in the kidneys even against the background high blood pressure. A significant reduction in blood flow occurs in kidney disease due to severe stress or severe blood loss.

The main function of the kidneys is the secretion of urine. This process is possible due to glomerular filtration, subsequent tubular secretion and reabsorption. The formation of urine in the kidneys occurs as follows:

To begin with, blood plasma components and water are filtered through a three-layer glomerular filter. Formed plasma elements and proteins easily pass through this filtering layer. Filtration is carried out due to constant pressure in the capillaries inside the glomeruli.
Primary urine accumulates inside the collecting cups and tubules. From this physiological primary urine, nutrients and fluids are absorbed.
Next, tubular secretion is carried out, namely the procedure for purifying the blood of unnecessary substances and transporting them into the urine.

Hormones have a certain effect on the excretory functions of the kidney, namely:

Adrenaline, produced by the adrenal glands, is needed to reduce urine formation.
Aldosterone is a special steroid hormone that is produced by the adrenal cortex. A lack of this hormone leads to dehydration, salt imbalance and a decrease in blood volume. Excess of the hormone aldosterone promotes salt and fluid retention in the body. This in turn leads to edema, heart failure and hypertension.
Vasopressin is synthesized by the hypothalamus and is a peptide hormone that regulates fluid absorption in the kidneys. After consumption large quantity water or when its content in the body exceeds the norm, the activity of the hypothalamic receptors decreases, which helps to increase the volume of fluid excreted by the kidneys. When there is a lack of water in the body, the activity of the receptors increases, which in turn leads to a decrease in urine secretion.

Important: against the background of damage to the hypothalamus, the patient experiences increased diuresis (up to 5 liters of urine per day).

Parahormone is produced by the thyroid gland and regulates the process of removing salts from the human body.
Estradiol is considered a female sex hormone that regulates the level of phosphorus and calcium salts in the body.

The following functions of the kidneys in the human body can be listed:

homeostatic;
excretory or excretory;
metabolic;
protective;
endocrine.

The excretory role of the kidneys is to filter the blood, cleanse it of metabolic products and remove them from the body. At the same time, the blood is cleared of creatinine, urea, and various toxins, such as ammonia. Various unnecessary organic compounds (amino acids and glucose), mineral salts that enter the body with food are also removed. The kidneys remove excess fluid. The processes of filtration, reabsorption, and renal secretion are involved in the implementation of the excretory function.

During one day, 1500 liters of blood are filtered through the kidneys. Moreover, approximately 175 liters of primary urine are immediately filtered. But since liquid is absorbed, the amount of primary urine is reduced to 500 ml - 2 liters and is excreted through the urinary system. In this case, urine is 95 percent liquid, and the remaining five percent is dry matter.

Attention: when the excretory function of an organ is disrupted, toxic substances and metabolic products accumulate in the blood, which leads to general intoxication of the body and subsequent problems.

Do not underestimate the importance of the kidneys in regulating the volume of intercellular fluid and blood in the human body. This organ is also involved in the regulation of ion balance, removing excess ions and bicarbonate protons from the blood plasma. It is able to maintain the required volume of fluid in our body by adjusting the ionic composition.

Paired organs are involved in the breakdown of peptides and amino acids, as well as in the metabolism of lipids, proteins, and carbohydrates. It is in this organ that regular vitamin D is transformed into active form, namely vitamin D3, which is necessary for the normal absorption of calcium. Also, the kidneys are an active participant in protein synthesis.

The kidneys are an active participant in the process of synthesis of the following substances and compounds necessary for the body:

Renin is a substance that promotes the production of angiotensin 2, which has a vasoconstrictor effect and regulates blood pressure;
Calcitriol is a special hormone that regulates calcium metabolic processes in the body;
erythropoietin is necessary for the formation of bone marrow cells;
Prostaglandins are substances involved in the process of regulating blood pressure.

Regarding protective function organ, it is associated with the removal of toxic substances from the body. These include some medicines, ethanol, drugs, including nicotine.

Negatively affects kidney function overweight, hypertension, diabetes mellitus and some chronic diseases. Harmful for them hormonal drugs and nephrotoxic drugs. The functioning of the organ may suffer due to a sedentary lifestyle, as this will contribute to disruption of salt and water metabolism. It can also lead to the deposition of kidney stones. Causes of kidney failure include the following:

traumatic shock;
infectious diseases;
poisoning;
disturbance of urine outflow.

For normal functioning of the organ, it is useful to drink 2 liters of liquid per day. It is useful to drink berry fruit drinks, green tea, purified non-mineral water, parsley decoction, weak tea with lemon and honey. All these drinks are good prevention of stone deposits. Also, to preserve the health of the organ, it is better to give up salty foods, alcoholic and carbonated drinks, and coffee.

The kidneys serve as a natural “filter” of blood, which, when working properly, is removed from the body harmful substances. Regulating kidney function in the body is vital for the stable functioning of the body and immune system. For a comfortable life you need two organs. There are cases that a person remains with one of them - it is possible to live, but he will have to depend on hospitals for the rest of his life, and the protection against infections will decrease several times. What are the kidneys responsible for, why are they needed in the human body? To do this, you should study their functions.

Let's delve a little into the anatomy: the excretory organs include the kidneys - this is a paired bean-shaped organ. They are located in the lumbar region, with the left kidney being higher. This is nature: above the right kidney there is a liver, which prevents it from moving anywhere. Regarding the size, the organs are almost the same, but note that the right one is slightly smaller.

What is their anatomy? Externally, the organ is covered with a protective shell, and inside it organizes a system capable of accumulating and removing fluid. In addition, the system includes parenchyma, which creates the medulla and cortex and provides the outer and inner layers. Parenchyma is a set of basic elements that are limited to the connective base and the membrane. The accumulation system is represented by a small renal calyx, which forms a large one in the system. The union of the latter forms the pelvis. In turn, the pelvis is connected to bladder through the ureters.

One of the important filtration organs in the human body is the kidneys. This paired organ is located in the retroperitoneal space, namely on the posterior surface of the abdominal cavity in the lumbar region on both sides of the spine. The right organ is anatomically located slightly lower than the left. Many of us believe that the only function of the kidney is to produce and excrete urine. However, in addition to the excretory function, the kidneys have many other tasks. In our article we will take a closer look at what the kidneys do.

Peculiarities

The structure and formation of urine

The various functions of the human kidneys are realized due to the fact that nephrons are of three types, depending on the structure of their tubules and location:

Intracortical.
Superficial.
Juxtamedullary.

There is constant constant blood flow in the kidneys even against the background of high blood pressure. A significant reduction in blood flow occurs with kidney disease, due to severe stress or severe blood loss.

To begin with, blood plasma components and water are filtered through a three-layer glomerular filter. Formed plasma elements and proteins easily pass through this filtering layer. Filtration is carried out due to constant pressure in the capillaries inside the glomeruli.
Primary urine accumulates inside the collecting cups and tubules. From this physiological primary urine, nutrients and fluids are absorbed.
Next, tubular secretion is carried out, namely the procedure for purifying the blood of unnecessary substances and transporting them into the urine.

Regulation of renal activity

Hormones have a certain effect on the excretory functions of the kidney, namely:

Adrenaline, produced by the adrenal glands, is needed to reduce urine formation.
Aldosterone is a special steroid hormone that is produced by the adrenal cortex. A lack of this hormone leads to dehydration, salt imbalance and a decrease in blood volume. Excess of the hormone aldosterone promotes salt and fluid retention in the body. This in turn leads to edema, heart failure and hypertension.
Vasopressin is synthesized by the hypothalamus and is a peptide hormone that regulates fluid absorption in the kidneys. After drinking a large amount of water or when its content in the body exceeds the norm, the activity of the hypothalamic receptors decreases, which helps to increase the volume of fluid excreted by the kidneys. When there is a lack of water in the body, the activity of the receptors increases, which in turn leads to a decrease in urine secretion.

Important: against the background of damage to the hypothalamus, the patient experiences increased diuresis (up to 5 liters of urine per day).

Parahormone is produced by the thyroid gland and regulates the process of removing salts from the human body.
Estradiol is considered a female sex hormone that regulates the level of phosphorus and calcium salts in the body.

Renal functions

The following functions of the kidneys in the human body can be listed:

homeostatic;
excretory or excretory;
metabolic;
protective;
endocrine.

excretory

Attention: when the excretory function of an organ is disrupted, toxic substances and metabolic products accumulate in the blood, which leads to general intoxication of the body and subsequent problems.

Homeostatic and metabolic functions

Paired organs are involved in the breakdown of peptides and amino acids, as well as in the metabolism of lipids, proteins, and carbohydrates. It is in this organ that regular vitamin D is transformed into its active form, namely vitamin D3, which is necessary for the normal absorption of calcium. Also, the kidneys are an active participant in protein synthesis.

Endocrine and protective functions

The kidneys are an active participant in the process of synthesis of the following substances and compounds necessary for the body:

Renin is a substance that promotes the production of angiotensin 2, which has a vasoconstrictor effect and regulates blood pressure;
calcitriol is a special hormone that regulates calcium metabolic processes in the body;
erythropoietin is necessary for the formation of bone marrow cells;
Prostaglandins are substances involved in the process of regulating blood pressure.

As for the protective function of the organ, it is associated with the removal of toxic substances from the body. These include some medicines, ethyl alcohol, narcotic substances, including nicotine.

Prevention of kidney disorders

Excess weight, hypertension, diabetes and some chronic diseases negatively affect kidney function. Hormonal drugs and nephrotoxic drugs are harmful to them. The functioning of the organ may suffer due to a sedentary lifestyle, as this will contribute to disruption of salt and water metabolism. It can also lead to the deposition of kidney stones. Causes of kidney failure include the following: