The role of the liver in the human body, the causes and methods of prevention of its diseases. The liver and its functions in the human body Why do we need a liver in the body

The liver is the largest gland that performs numerous functions in the human body. It neutralizes toxins, produces enzymes, participates in blood circulation, stores vitamins and trace elements, and produces hormones.

In medicine, the liver is compared with an entire biochemical laboratory; its tasks include more than 500 important functions. To describe all the functions of this organ, not a single page of text in small print is required, so in our article we will briefly describe the functions of the liver, choosing from all the most important and basic ones.

The liver is a large abdominal glandular organ of the digestive system. Localization of the organ - the right upper quadrant of the abdomen under the diaphragm. It is a vital organ that supports varying degrees all other organs and systems of the body, as well as performing numerous biochemical processes.

The liver is the second largest organ, weighing 1.4 kg. The organ is divided into 4 lobes and a soft structure. Color - pink-brown. In addition, several bile ducts.

The development of the liver is noted at the 3rd week of fetal development, reaching full maturity at 15 years. It lies almost entirely behind chest, but at the same time, the lower insignificant part of the organ can be probed during inspiration along the right costal arch.

Covered with a layer connective tissue, which was called the Glisson capsule. This capsule is distributed over the entire surface of the liver, with the exception of small hepatic vessels. to the diaphragm and abdominal wall The liver is attached by the falciform ligament, while dividing it into a small left lobe and a large right one.

Interesting. The description of the liver was made as early as 1957 by the French surgeon Claude Quinaud. He singled out 8 segments of the liver and described each of them. To date, medicine, thanks to radiographic studies, describes an average of 20 segments, each of which has its own independent vascular branches.

Each is divided into lobes, represented by discrete hexagonal clusters of hepatocytes. Hepatocytes are cells of the liver parenchyma that make up from 60 to 80% of the volume of the liver mass.

They perform such important functions in the body:

• synthesis and accumulation of proteins;
• transformation of carbohydrates;
• synthesis of cholesterol, phospholipid and bile salts;
• detoxification, modification and removal of endogenous components;
• initiation of the process of bile formation.

The liver performs important functions in the body: it maintains the concentration of glucose in the blood, the secretion of bile favors normal digestion and detoxification.

Attention. In view of the performance of numerous functions, the liver is a rather susceptible organ to various damages and negative influences.

Liver functions

The main task of the body is:

• cleanse the body of decay products;
• reduce exposure to toxins.

The activity of the liver and metabolic disorders are affected by the negative environment, ecology, low-quality products and frequent stress.

All functions performed by the liver are conditionally divided into 3 large blocks:

1. external functions. Production, secretion and excretion of bile in duodenum.
2. Internal functions. Blood formation and metabolic processes.
3. barrier functions. Fight against toxins and various toxic substances and their destruction.

Let's take a closer look at the functions performed by the liver in the body.

Digestive (excretory)

The liver is an organ that is directly involved in the processes of digestion, it has an enzymatic value. The liver is the largest gland in the body and is responsible for producing bile.

Normally, from 0.5 to 1 kg of bile is produced per day. This component is necessary for the breakdown of fats.

The composition of bile is as follows:

• water - 82%;
• bile acids - 12%;
• lecithin - 4%;
• cholesterol - 0.7%;
• bilirubin and other substances - 1%.

When interacting with the products entering the body, bile acids and their salts break down fats into tiny particles, which facilitates the process of assimilation and digestion.

In addition, bile acids contribute to the activation of the absorption process of such components:

• cholesterol;
• insoluble fatty acids;
• calcium salts;
• vitamins K, E and group B.

The functions of bile are as important as the functions of the liver.

Thanks to this substance, the following mechanisms occur in the body:

• inhibition of the processes of decay in the intestines, since bile stimulates the tone of the small intestine;
• digestion and assimilation of proteins and carbohydrates;
• stimulation of the production of pancreatic juice by the pancreas;
• activation of bile production in the liver.

As a result of the work of bile, all harmful and toxic substances are removed from the body. With the development of gallstone disease or with obstruction of the ducts (narrowing of their lumen), the mechanism for removing toxins is disrupted, which negatively affects the functioning of the liver, the outflow of bile worsens, and this, in turn, leads to stagnation of bile in the body.

Homeostatic

This function is also called biochemical, since the following reactions occur in the liver:

• breakdown of amino acids;
• glucose production;
• transamination.

The energy produced by such processes is an important component of energy metabolism. With the breakdown of hemoglobin, production begins, which in turn has a toxic effect on the body. The present protein transforms bilirubin into the form of a substance that is transported to the intestines and then exits along with the feces.

Hemostatic

Thanks to this function, the liver produces proteins, the so-called globulins. They enter the bloodstream, where they are important - they provide the necessary degree of blood clotting.

Barrier

Throughout the day, the body is exposed to negative effects, they can be exerted by:

• aggressive environment;
• poor quality food;
• medications;
• viruses and bacteria.

The antitoxic (barrier) function of the liver is aimed at combating such negative mechanisms, its task is to:

• neutralization of toxins;
• splitting of poor-quality products entering the body into scanty substances, which are subsequently excreted from the body through the intestines.

The detoxification function of the liver is due to the purification of the venous blood from absorbed substances, which occurs in the portal vein. Thanks to specialized macrophages (Kupffer cells), harmful particles are captured in the blood, they are bound by acids, and subsequently excreted from the body along with bile.

Attention. The barrier function of the liver depends entirely on the amount of protein that enters the body. Therefore, to maintain the normal functioning of the body, it is necessary to eat properly and qualitatively and observe a full drinking regimen.

Blood deposit

The liver is far from the last position in the normalization of blood flow and blood pressure. The organ is a kind of "depot" for blood, in the hepatic vessels there is a constant regulation of blood, the volume can reach 1 liter.

metabolic

This function is one of the most basic and voluminous performed by the liver. As you know, in the human body regularly occur various chemical reactions, and the largest gland takes an active part in these mechanisms, such as:

• fatty;
• protein;
• carbohydrate;
• lipid;
• pigmented;
• vitamin;
• hormonal;
• cholesterol.

The liver performs the following tasks:

• reserves protein;
• maintains a supply of glycogen (an energy substance during the breakdown of glucose);
• produces bile acids.

Table number 1. Metabolic functions of the liver.

Important. For a normal existence, absolutely all cells require an external feeding source. The liver is such a source, it is the reserve fund of the body's energy reserves, such as triglycerides, proteins and glycogen.

Endocrine (hormonal metabolism)

The liver provides normal level hormonal levels in the body. The organs of the endocrine system constantly produce hormones that the large gland regularly deactivates them.

In the liver, the process of combining steroid hormones and glucuronic fatty acid takes place, as a result, the hormones are inactivated. In violation of the function of hormone metabolism in the liver, there is an increased content of aldosterone hormones and produced by the adrenal cortex. This pathological mechanism can lead to the development various diseases, swelling and the appearance of hypertension.

The liver is able to inactivate hormones:

• produced by the thyroid gland;
• insulin;
• antidiuretic hormone;
• sexual.

In addition, the liver normalizes the concentration in the body of such neurotransmitters:

• histamine;
• serotonin;
• catecholamine.

We also note that the liver, even at the beginning of its embryonic development, produces hormones that promote the growth and development of the human body.

Important. Liver hormones are produced and have a significant impact on the body throughout a person's life. They contribute to the growth and development of the body, maintain a normal level of blood pressure, enhance the body's natural resistance to adverse factors.

In the human body, there are a number of unique hormones that are directly involved in the biochemical reactions of the liver.

Table number 2. Hormones involved in the biochemical reactions of the liver.

The endocrine function of the liver consists in the following processes:

1. Metabolism and inactivation of steroid hormones. If the liver fails, the concentration of steroid hormones increases, the splitting process is disturbed. Hence the emergence of numerous diseases. In the body, there is an increased accumulation of aldosterone, which leads to fluid retention. Swelling appears, blood pressure rises.
2. Inactivation of neurotransmitters. With insufficient suppression of the activity of neurotransmitters by the liver, the patient develops various mental illnesses.

Elimination

The most basic and important stage in the work of the liver is the process of elimination (removal of toxins from the body). Elimination is a complex of processes that contribute to the removal of toxins from the body in natural ways. Toxic and harmful substances can be removed in a transformed form or in an unchanged form.

Malfunctions in the liver

Liver dysfunction is not a separate pathology, but a designation of any malfunction of the organ. The liver is involved in numerous chemical and biological reactions, each of which has its own characteristics. Violation of any chemical process leads to liver dysfunction.

These violations are reflected by the following mechanisms:

• blood ceases to be purified;
• decay products are not fully excreted from the body;
• toxins and other harmful components enter the bloodstream, which provokes a breakdown of other organs and systems;
• water exchange is disturbed;
• the immune defense of the body is reduced;
• disorders of the nervous system appear;
• the degree of blood clotting decreases;
• there is a breakdown of the entire digestive system;
• the skin becomes dry, itching and peeling appear.

Attention. The liver does not have nerve endings, which does not provoke the patient to feel pain when it is dysfunctional. However, any pathological changes are accompanied by separate atypical signs that experienced doctor is obliged to recognize and promptly begin to restore liver function.

Causes of liver failure

There can be several reasons for liver dysfunction, they are all divided into 2 large groups:

• external;
• internal.

TO external reasons can be attributed:

• aggressive environmental conditions;
• unhealthy lifestyle (alcohol abuse, smoking, drug addiction);
• poor-quality food and non-compliance with the regime;
• long-term medication.

Internal factors include:

• pathological processes in other organs, as a rule, the liver suffers from diseases of the gallbladder, stomach,;
• constant presence in stressful situations;
• the presence of mental illness;
• infectious diseases;
• high physical activity.

Symptoms

Failures of each of the functions of the liver manifest themselves accordingly, while it is worth remembering that there are no nerve endings which complicates the diagnosis. However, we note that under a negative influence for a long time, the organ begins to change its size, swelling of the parenchyma is noted, and this, in turn, leads to an increase in pressure on neighboring organs. The appearance of such changes poses a serious danger to human health.

Symptoms of disorders of liver function in the early and late stages is excellent, therefore, we will consider what signs of liver dysfunction may be at the beginning of pathological changes and with their further development.

early signs

This period, as a rule, is asymptomatic, the patient continues to lead his usual mode of life, and this gradually aggravates the situation. Minor manifestations are attributed to stress, poor ecology, fatigue. As a result, the patient seeks medical care when already pathological process gained momentum, and sometimes became life-threatening.

Liver dysfunction can be recognized in the early stages by the following signs:

• unexplained fatigue;
• depression, depression for no particular reason;
• sleep disturbance;
• poor appetite;
• failures of metabolic processes;
• nausea, often accompanied by vomiting (as a rule, there is morning vomiting with bile contents);
• belching with gases;
• bitterness in the mouth;
• skin itching;
• yellowish skin on the face;
• the appearance of a rash and redness on the skin (in particular, it manifests itself in the intimate area);
• the appearance of angiomas (spider veins) in the neck, face, hands, feet.

Important. During the period of gestation, women are often diagnosed with liver dysfunction, which is accompanied by nausea and constant vomiting.

When any characteristic feature you need to go to the clinic for medical help.

late signs

In the early stages of pathological changes, people rarely go to the hospital, but when more severe symptoms exists high risk development of serious consequences.

Progressive pathologies of the liver are manifested as follows:

• pain in the right hypochondrium is aching, pulling or sharp;
• sweetish special smell from the mouth;
• the skin becomes yellow, this indicates a disorder of bilirubin metabolism;
• pallor skin indicates a decrease in the concentration of red cells in the blood (a sign of anemia);
• the appearance of age spots on the skin;
• appearance a large number « spider veins» on the skin;
• manifestation of veins on the abdomen;
• red spots on the palms appear as a result of high estrogen content;
• the tongue becomes crimson;
• in women during menstruation, signs of dysmenorrhea appear (intense pain in the lower abdomen, weakness, nausea, dizziness, headache);
• in men, there is a high content of estrogen, manifested by an increase in the size of the mammary glands, loss of hairline, male weakness;
• dyspeptic symptoms (lack of appetite, nausea, vomiting, heaviness in the supragastric region, constipation, bloating);
• sudden weight loss;
• various psychoneurological disorders;
• endocrine system disorders;
• fever;
• the appearance of xanthoma and xanthelasma in the eyelids, hands, feet, elbows, buttocks.

If a patient is diagnosed with many of the above signs, this indicates the severity of the problem. The severity of the disease is determined by the results laboratory tests And instrumental diagnostics. In accordance with the data obtained, the doctor determines the necessary method for treating liver dysfunction.

What are the consequences of liver dysfunction?

The signs of liver dysfunction that have appeared cannot go away on their own, especially since with the progression of pathological changes, the patient undergoes high risk development of serious consequences.

Often, against the background of liver dysfunction, such diseases occur:

• psoriasis;
• eczema;
• ascites;
• varicose veins in the abdomen.

If you systematically ignore the symptoms that have appeared, against this background, the development of chronic processes is not excluded.

Attention. When portal hypertension there is a high risk of death.

The lack of adequate drug therapy inevitably leads to the development of liver failure. The most serious signs include the presence of a "liver" sweet smell from the mouth, this indicates extensive liver damage and liver failure.

Diagnostics

Liver diagnostics is prescribed in such situations:

• immediately upon the appearance of characteristic symptoms;
• during pregnancy (it is recommended to check at the planning stage of conception);
• before surgical operations;
• front drug therapy involving the use of potent or psychotropic drugs.

The most effective, fastest and easiest way to diagnose liver dysfunction is a biochemical blood test.

This diagnostic method allows you to determine the following indicators:

1. The concentration of liver enzymes (ALT and AST). An increased content of enzymes indicates the destruction of hepatocytes; the development of hepatitis, cirrhosis, or oncology can also be suspected. The higher the AST and ALT values, the higher the degree of destruction of the organ.
2. Bilirubin. An increased concentration of the substance indicates that bilirubin is not excreted from the body and there are pathological reasons for this. The pigment substance accumulates in the blood, spreads throughout the body and thus manifests itself as yellowness of the skin and sclera.
3. Alkaline phosphatase. The increased content of the substance is evidence serious damage liver, high suspicion of tumor formation.
4. Albumen. It is a protein produced by the liver. With the appearance of any damage to the body, its concentration in the blood drops sharply.

In addition to biochemistry, the doctor prescribes a blood test for liver markers to patients, as well as general analysis blood. For research, in addition to blood, the patient's feces and urine are needed.

In order for a biochemical blood test to show a reliable result, the patient must adhere to certain rules.

This:

1. Blood for analysis must be taken on an empty stomach. Since the liver is an organ that is directly involved in the process of digestion, then, accordingly, after eating, the blood will contain unreliable indicators of the substances contained. In addition, within 3 days before the test, a person must refrain from eating fatty, fried, spicy and salty foods.
2. Alcohol is strictly prohibited. Even the smallest dose of alcohol can lead to a high load on the liver, respectively, the blood changes its properties, including losing its clotting properties.
3. To give up smoking. Smoking also has a negative effect on blood counts. Laboratory workers strongly recommend that you refrain from smoking for at least 12 hours before donating blood for analysis.
4. Sports activities are not recommended. 3 days before the analysis, a person should refrain from performing strength exercises and active sports. It is also worth avoiding stressful situations, excitement and any psycho-emotional stress.
5. Refusal of treatment. If the patient is undergoing any drug treatment, doctors strongly advise for 7 days before the analysis to refuse to take any medicines. In cases where refusal of treatment cannot be due to medical reasons, this must be reported to the attending physician.

Blood sampling for biochemistry is carried out intravenously. For a more accurate clinical picture of pathological changes in the liver, it is advisable to additionally instrumental methods diagnostics.

Instrumental diagnostics includes:

1. ultrasound. Thanks to this method, it is possible to determine the change in the size of the organ and the degree of tissue damage.
2. CT and MRI. These are modern diagnostic procedures, which allow obtaining a multidimensional image of an organ and determining the degree of tissue damage with maximum accuracy.
3. Biopsy. This method is quite painful and unpleasant for the patient. It is resorted to only in the most serious situations, when it comes to suspicions of oncological education or hepatitis C.
4. Radionuclide scanning. This method involves the introduction of a special solution (contrast agent) into a vein, which, along with the blood flow, spreads throughout the body, including getting into the liver. With the help of a special scanner, the organ is examined for the presence of cysts, tumors, the size of the liver is detected, and the number of affected cells is determined.
5. Laparoscopy. This method of liver diagnostics is performed under anesthesia. Its essence is the introduction of an optical tube through a small incision in the peritoneum, through which you can examine the surface of the organ and determine pathological changes in tissues, in addition, in this way you can take a small piece of tissue for further research.

Regeneration

Science is still researching the regenerative function of the liver. Many of us have heard that the liver is a unique organ, the tissues of which are capable of self-healing after damage. This process is facilitated by the genetic information found in the set of chromosomes.

Thanks to this function, liver cells are able to synthesize even when part of the organ is removed. The functional abilities of the liver are fully restored, and the size of the organ returns to its previous state.

The period of liver regeneration according to research work is 3 to 6 months.

The growth of scar tissue can worsen this process. In this situation, there is a high risk of developing liver failure and replacing healthy tissue.

After the age of 40, the ability of liver regeneration weakens, while the organ itself begins to decrease in size, and the production of albumins and globulins also decreases. In addition, the volume and composition of bile undergoes changes, but these mechanisms do not affect the vital activity of the body.

Regular liver cleansing proper nutrition and maintaining healthy lifestyle life allow you to maintain the normal functionality of the body, without exposing the body and internal organs pathological disorders.

The video in this article will tell readers about the unique capabilities of such an organ as the liver.

Shop for biochemical reactions in the body. A huge burden of responsibility for participating in many processes falls on her shoulders. It is the largest organ of the body - its weight can reach one and a half kilograms. Continuous work on cleansing the body and metabolic processes puts it on a podium among all organs.

The liver is able to independently create most of the nutrients required by the body, substances designed to protect it, carbohydrates and proteins. It produces bile - an acid involved in the breakdown of fatty foods and the absorption of fats. Without it, the digestion of fats would be impossible. In addition, the liver is involved in the production of proteins responsible for blood clotting.

This organ is often referred to as the "blood store" because it contains some emergency blood supply. Liver inactivate steroid hormones(both female and male).

Despite the ability of liver cells to recover, its diseases are quite common. The rate of cell recovery is several times lower than the rate of their destruction. Therefore, the constant use of alcohol, tobacco, fatty foods gradually leads to liver failure, and ultimately to cirrhosis.

The site provides background information for informational purposes only. Diagnosis and treatment of diseases should be carried out under the supervision of a specialist. All drugs have contraindications. Expert advice is required!

General information

As everyone knows, the liver is an unpaired organ located in the right hypochondrium. With this knowledge of anatomy, everyone who is stabbed in the right side is immediately diagnosed with a liver disease. This is a fairly massive organ, its average weight is 1.5 kg. The liver has a separate vascular network, isolated from the general blood flow. And the reason for the isolated vascular network is the fact that blood flows into this organ from everything intestinal tract. At the same time, the liver is a natural filter for the blood flowing from the intestinal walls, it performs the function of primary sorting, synthesis and distribution of nutrients in the body. IN circulatory system liver drains blood from almost all organs abdominal cavity: intestines ( thin and thick stomach), spleen, pancreas. Further, the blood, having passed the filtration in the tissues of the liver, again returns to the big circle circulation. In order to understand how the liver functions, let's take a closer look at its anatomical and microscopic structure.

What does liver tissue look like under a microscope?

In the lumen of the portal vein, blood from the abdominal organs moves towards the hepatic lobules.

The hepatic artery carries unidirectional blood flow from the heart to the liver tissues. This blood is enriched with nutrients and oxygen. Therefore, the main function of this network is to provide the liver tissue with energy and building resources.

along the bile duct synthesized by hepatocytes ( liver cells) bile flows from hepatic lobule towards the gallbladder or duodenal lumen.

Recall that through the portal vein, blood flows to the liver mainly from the intestines, with all substances dissolved in the blood as a result of digestion. The hepatic artery carries oxygenated and nutrient-rich blood from the heart to the liver. Inside the hepatic lobule, the vessels through which blood enters the hepatic lobule merge, forming an expanded cavity - sinusoidal capillaries.
Passing through the sinusoidal capillaries, the blood slows down significantly. This is necessary so that hepatocytes have time to capture substances dissolved in the blood for their further processing. Nutrients undergo further processing and are distributed through the bloodstream through the vasculature, or accumulated in the form of reserves in the liver. Toxic substances are captured by hepatocytes and neutralized for subsequent excretion from the body. After going through the sinusoidal capillaries, the blood enters the central vein located in the center of the hepatic lobule. Through the hepatic vein, blood is removed from the hepatic lobule towards the heart.

Hepatic cells are arranged in the form of unicellular plates located perpendicular to the walls of the central vein. Outwardly, it resembles a book turned 360 degrees, where the end is the central vein, and the sheets are trabeculae, between which the vessels are intertwined.

Metabolic processes in the liver - how do they occur?

With regard to proteins, fats and carbohydrates, the fact that these substances can be synthesized in the liver is important. Moreover, carbohydrates can be synthesized from fats or amino acids. Fats can be synthesized from the breakdown products of carbohydrates and amino acids. And only amino acids cannot be synthesized from carbohydrates or fats. Vitamins are also not synthesized in our body. Therefore, without a constant supply of amino acids and vitamins with food, it is impossible to feel healthy for a long time.

So, in the process of digestion in the blood flowing from the walls of the intestine, there are many split to the level of the smallest fatty particles ( chylomicrons). In this blood, fats form an emulsion which, according to appearance looks like milk. Carbohydrates enter the blood in the form of molecules of various structures ( fructose, maltose, galactose, etc.).

Amino acids- these are the structural units of the protein that enter our body in the form of individual molecules or in the form of short chains of particles bonded to each other.
Amino acids - these important substances for our body are used with particular thrift by liver cells. Enzymes and blood proteins are synthesized from them. Some of the synthesized protein molecules are again returned to the blood for transportation to organs and tissues in the form of amino acids or blood plasma protein - albumin. Some of the amino acids are broken down to build other amino acid molecules or other organic substances.

vitamins- these substances enter our body during digestion, some of them are synthesized by the intestinal microflora. However, all of them enter the body, passing through the liver tissue. Vitamins are indispensable substances that enter the liver tissue with the bloodstream. Vitamins are actively absorbed by the cells of the body. Some of the vitamins are immediately integrated into synthesized enzymes, some are stored by liver cells, some are redirected with the blood flow flowing from this organ to peripheral tissues. During the passage of the hepatic sinuses, organic substances and vitamins are captured by the hepatic cells and move inside the hepatocyte. Further, depending on the state of the organism, the processes of transformation and distribution take place.

Carbohydrates most actively processed in the liver. Diverse forms of carbohydrates are converted into a single - glucose. Further, glucose can be released into the bloodstream and rush through the central vein to the systemic circulation, go to the energy needs of the liver, or be broken down to produce the substances necessary for the body or accumulate in the form of glycogen.

Fats- enter the liver in the form of an emulsion. When they enter the hepatocyte, they are split, the fats are split into components glycerol and fatty acids. In the future, from the newly synthesized fats, transport forms are formed - lipoproteins from cholesterol molecules, lipids and protein. It is these lipoproteins that, entering the bloodstream, deliver cholesterol fats to peripheral tissues and organs.

The liver as a factory for collecting complex proteins, carbohydrates and fats

Albumen is a low molecular weight protein with a molecular weight of 65,000. Serum albumin is synthesized exclusively by the liver. The amount of albumin contained in a liter of blood serum reaches 35 - 50 grams. Albumin performs many functions of the blood: it is one of the transport forms of protein in the body, carries out the transfer of certain hormones, organic substances and medications, provides oncotic blood pressure ( this pressure prevents the exit of the liquid part of the blood out of the vascular bed).

Fibrin- This is a low molecular weight protein in the blood, formed in the liver due to enzymatic processing and ensuring the coagulation of the blood and the formation of a blood clot.

Glycogen is a molecular compound that combines carbohydrate molecules in the form of a chain. Glycogen acts as a depot for carbohydrates in the liver. In case of need for energy resources, glycogen is broken down and glucose is released.

The liver is an organ in which there is a constant high concentration of essential structural elements: proteins fats carbohydrates. For their transportation or storage in the tissues of a given organ, it is necessary to synthesize more complex molecules. Some of the synthesized molecules and microscopic structures are only transport forms of proteins ( albumin, amino acids, polypeptides), fat ( low density lipoproteins), carbohydrates ( glucose).

Bile is one of the main factors in the breakdown of fats.

The liver is an indispensable conveyor of the body

The liver is the largest gland responsible for a number of important biochemical processes in the human body. The functions of the liver are diverse. It is widely believed that this organ is most closely associated with the digestive tract. This statement is correct. However, the liver also interacts with the nervous, endocrine, cardiovascular systems. She has been assigned the most important role in maintaining metabolism and neutralizing dangerous toxins. This function is especially important in the presence of stress and a sharp deterioration in life-supporting processes.

What organ system does the liver belong to?

The human liver, figuratively speaking, acts as a central one. Since the product of the work of this organ is the secretion necessary for the digestion of food, it is referred to as the digestive system. Iron produces enzymes necessary for the absorption of food, destroys toxins. With its participation, all types of metabolism occur:

• fatty;
• carbohydrate;
• protein;
• pigmentary;
• water.

Although the liver produces several types of hormones, it is not included in the endocrine system.

Anatomy and internal structure of the liver

The liver is the largest gland in the digestive system. Its weight can be from one and a half to two kilograms. - the right, and to a lesser extent the left hypochondrium of the body. characterized by its delimitation into 2 halves (shares). One part is separated from the other by the main fold.

The functional unit of the liver is the hepatic lobule. It is understood as a tiny area in the form of a hexagonal prism 1.5 mm wide and about 2.5 mm high. The entire organ consists of more than 500 thousand such formations, which together perform the main liver functions.

Each of the lobules is separated from the next by the thinnest connecting partition, forming a triangle. It is located in it. On the diagrams of the structure of the hepatic lobule, one can see plates (beams) converging together in the form of cells - hepatocytes. In the middle of the site is the central vein. From it to the edge of the lobule, liver cells scatter in rows or chains.

What is the liver for?

The main function of the liver in the human body is to neutralize toxins (poisons). They enter the body with food, drink, inhaled air.

Iron acts as a kind of filter that neutralizes harmful products. She is responsible for many processes and functions:

• participates in the work of the digestive tract, carries out the synthesis of bile acids and corrects the separation of bile;
• synthesizes protein substances - albumin, fibrinogen, globulins;
• regulates protein metabolism;
• splits and decomposes erythrocytes;
• performs detoxification, prevents poisoning by toxic masses, poisons and allergens;
• produces carbohydrate metabolism, converts glucose into glycogen;
• is stored with vitamins, calcium, iron necessary for hematopoiesis;
• brings out decay products (phenol, uric acid, ammonia, etc.);
• acts as an emergency "warehouse" of blood for its urgent compensation in case of volumetric blood loss.

Detoxification

To understand how the human liver works, it should be remembered that we are dealing with the most complex organ. The complex circulatory system and intricate bile capillaries allow the organ to perform its tasks.

It may seem incomprehensible, if the main function of the liver is to neutralize toxins, then where do they come from if we eat, for example, only healthy food. Biochemical reactions occurring in the body cause the breakdown of amino acids. As a result, decay products are formed, including a toxic compound - ammonia, which can poison a person from the inside if its excretion is disturbed. With the help of the liver, a constant process of formation of urea is ensured, into which ammonia is converted. Ammonia has toxic abilities - its excess, which leads to coma and death.

Performing its direct functions, the liver converts poisons, toxins, and other active compounds into less harmful formations, which are then easily excreted with feces. The breakdown of amino acids and the conversion of ammonia into urea is a fairly stable process. It does not stop even in the absence of 90% of the liver tissue.

Digestive function

The role of the liver in the digestive system cannot be overestimated. She is responsible for the formation of bile. The gland produces the necessary amount of bile, which is formed from:

• pigments;
• bile acids;
• bilirubin;
• cholesterol.

Bile enhances intestinal motility, helps to absorb vitamins, activate other enzymes involved in the digestion of food (for example, pancreatic juice).

The separation of bile in the liver (choleresis) occurs continuously. The secretion of bile (cholekinesis) is carried out only during digestion. When a person begins to eat, bile from the gallbladder through the duct enters the duodenum. In case of violations in the work of the hepatobiliary system, the production of enzymes involved in the processing of proteins, fats and carbohydrates decreases. The intestines begin to work poorly, the absorption of food worsens.

Participation in metabolism

The value of the liver in ensuring human life is great. It performs not only the functions of digestion and blood circulation, but also performs metabolism, including hormonal. disintegrate in the liver tissue the following types hormones:

• insulin;
• thyroxine;
• glucocorticoids;
• aldosterone;
• estrogen.

It is not cholesterol that is present in the blood, but its connection with protein - lipoproteins. Depending on the density, they are called "good" and "bad". Lipoproteins, which have a high density, are useful for humans, in particular, they prevent atherosclerosis. Cholesterol is the base, a necessary component for the formation of bile. "Bad" protein compounds are bad cholesterol.

In the process of carbohydrate metabolism, the liver absorbs galactose. In hepatocytes, it is converted to glucose, which is then converted to glycogen. This substance is intended to maintain a normal concentration of glucose in the blood. When sugar levels rise after a meal, liver cells begin to synthesize glycogen, as well as deposit it (put it aside).

Synthesis of proteins and blood coagulation factors

The liver is extremely important in the life of the body. It provides a constant concentration of nutrients in the blood and maintains the plasma composition at the right level. It also coordinates the connection of the portal circle of blood entering through the portal vein with the general circulation. It synthesizes:

• protein coagulation factors;
• albumins;
• plasma phosphatides and most of its globulins;
• cholesterol;
• carbohydrates and other enzymes.

Other features

The liver has quite a few functions: from the metabolism of carbohydrates and proteins to the breakdown of hormones and blood clotting. So, if for some reason the body is not provided with a sufficient amount of protein, the liver directs its accumulated reserve to “general” needs. By exchanging vitamins, the gland produces a certain amount of bile acids that transport fat soluble vitamins into the intestines. She delays some vitamins, creating their reserve. There is also an exchange of trace elements, such as manganese, cobalt, zinc and copper.

One of the basic functions of the liver is a barrier. Under conditions of constant attacks of toxins on the human body, this gland acts as a reliable filter, preventing poisoning.

One more essential function is immunological. The neutralizing function can activate the immune system in response to tissue damage and various infections.

Innervation and features of blood supply

Blood supply to the liver is carried out in two ways - from the portal vein and the hepatic artery. The value of the second source, although less productive, cannot be underestimated, since the arterial blood comes already enriched with the oxygen necessary for the body.

Innervation occurs with the participation of the hepatic plexus, which is located in the middle of the sheets of the hepatoduodenal ligament along the periphery of the hepatic artery. This process involves the branches of the diaphragmatic nodes and vagus nerves.

Factors that negatively affect liver function

Violation of functions occurs during (inflammation), (cell degeneration), tumor diseases in the organ. Although the liver has a high recovery rate, if it is not helped, there is a risk of losing vitality. important organ. Then only a transplant will help.

Violates the normal functioning of education due to improper metabolism. With an increase in the amount of cholesterol or bilirubin, the volume of salt necessary for their dissolution decreases. This causes the appearance of dense formations called calculi.

Another common cause of pathology are diseases of other digestive organs, in particular, the pancreas. Bile metabolism disorders also occur with malnutrition.

The first signs of organ dysfunction

Since the liver has a fairly large compensatory capacity, diseases, especially at first, occur without pronounced symptoms. Since the gland belongs to the digestive system, the diseases that have arisen are manifested by malfunctions in the digestive tract. Patients feel discomfort, pain in the right hypochondrium, a feeling of fullness. Quite often there are diarrhea and constipation, accompanied by nausea. There may be discoloration of the stool, a change in the color of urine and.

• fever;
• loss of appetite;
• feeling of being broken;
• chills;
• a sharp decrease in muscle mass.

How to keep your liver healthy

To keep the liver healthy so that it can cope with its functions, it is necessary to limit alcohol consumption, move more, change - reduce the intake of fats and carbohydrates. It is necessary to minimize the use of antidepressants, antibiotics, painkillers. Attention should be paid to personal hygiene, wash hands with soap and water after the street and before eating. It is important to control weight, use a calorie calculator to prevent obesity.

Literature

• Vengerovsky, AI Pharmacological approaches to the regulation of liver functions / AI Vengerovsky // Bulletin of Siberian Medicine. - 2002.
• Pirogova I. Yu. Regeneration therapy of chronic hepatitis and liver cirrhosis using fetal tissue transplantation / I. Yu. Pirogova, SA Pushkin // Cell transplantology and tissue engineering. - 2008. - No. 1. - P. 57–61.
• Polunina, T. E. Medicinal lesions of the liver / T. E. Polunina, I. V. Maev // Gastroenterology. - 2011. - No. 4. – 54 p.
• Prutkina, E. V. Patterns of changes in the detoxification function of the liver in viral hepatitis: Abstract of the dissertation for competition degree Candidate of Medical Sciences / Chita State Medical Academy of the Federal Agency for Health and social development. Chita, 2007.
• Roitberg G. E. Internal diseases. Liver, biliary tract, pancreas: tutorial/ G. E. Roitberg, A. V. Strutynsky. - M.: MEDpress-inform, 2016. - 94-116 p.
• Khalilulin, T. R. Liver dysfunctions: clinical and clinical and pharmacological studies: Dissertation for the degree of Candidate of Medical Sciences / Russian University Friendship between nations. Moscow, 2012.

Each person should understand what functions the liver performs. The stable functioning of the body directly depends on the health of this organ. The liver performs the functions of neutralizing toxins, and is also responsible for proper blood formation. The role of this gland in the digestive system is great: the liver is 80% hepatocytes, due to which part of the cholesterol is converted into bile acids, which gradually emulsify into lipids and promote the absorption of useful fat-soluble vitamins.

Description

Medical reference books contain a lot of information about the functions of the human liver. This body acts as a central chemical laboratory. Since as a result of the intensive work of this organ, bile is released, which is necessary for the digestion of food, it is referred to as the digestive system. Iron is responsible for the production of those enzymes that are necessary for the uniform absorption of food, destroying toxins along the way.

The main functions of the liver in the human body include all types of metabolism:

• Protein.
• Fatty.
• Water.
• Carbohydrate.
• Pigmentary.

Despite the fact that bile produces several types of hormones, it is not classified as an endocrine system.

Anatomy

The liver is the largest gland in the human digestive system. Depending on the physiological features its weight can vary from one to 2 kilograms. The organ is located in the right, as well as a smaller part of the left hypochondrium of the body. The principle of the structure of the liver is distinguished by a distinction into 2 lobes. There is a fold between the two halves.

The structure and functions of the liver depend on the state of individual lobules. This term is commonly understood as a small area in the form of a hexagonal prism 1.7 mm wide and 2.6 mm high. The organ itself consists of more than 500 thousand such lobules, which perform all the liver functions. The thinnest triangular films in which the bile ducts are hidden act as partitions. In the middle of the organ is the central vein.

Main functions

Stable work of the human body is simply impossible without the liver. It performs those functions that help cleanse the blood, promote good digestion, and also control the work of the digestive tract. That is why it is important to monitor the state of this body.

Initially, you need to figure out what functions the liver performs:

1. Qualitative biosynthesis of urea.
2. Removal of toxins, xenobiotics, poisons, biogenic amines from the body.
3. Metabolism of carbohydrates, proteins, nucleic acids, lipoproteins, vitamins, lipids.
4. Secretion of bile by hepatocytes.
5. In the body, the liver performs functions that are of the catabolic type. The liver is responsible for the production of hormones, as well as the breakdown of hemoglobin.
6. biosynthetic function. The glandular organ is responsible for the synthesis of those substances that are necessary for the stable functioning of the whole organism: triacylglycerol, glucose, phospholipids, lipoproteins, higher fatty acids.
7. Accumulation of valuable vitamins and microelements: glycogen, iron, fat-soluble vitamins.
8. Kupffer cells in the liver are involved in phagocytosis.
9. Biosynthesis of proteins of the coagulation system.
10. Bile excretion of bilirubin, cholesterol, bile acid, iron.

Digestive system

The liver is a multifunctional organ, the main task of which is the production of bile. This liquid has a characteristic yellowish-green tint, due to which a change from gastric to intestinal digestion is ensured. The liver continuously generates bile pigments under the influence of cellular breakdown of hemoglobin.

Before using this or that medicine, you need to familiarize yourself with what liver functions are necessary for normal digestion:

• A significant increase in the activity of intestinal enzymes.
• Qualitative emulsification of fats with a gradual increase in their area for joint hydrolysis by lipase.
• It is bile that is responsible for the absorption of amino acids, cholesterol and salts.
• Dissolution of products of lipid hydrolysis.
• Support for normal intestinal motility.
• Normalization of indicators of acidity of gastric juice.

If a person neglects regular food intake, then this leads to the fact that bile accumulates in the bladder with an increased concentration. Of course, this fluid is secreted differently from each person. But the sight of food, its smell and the very reception always cause the gallbladder to relax, followed by contraction.

Work failures

If the liver does not perform the functions on which the performance of other organs depends, then various ailments begin to develop in the body. In medical practice, there are many different cases of disease of the gland itself. All these diseases can be divided into several main groups:

• Impaired blood supply to the hepatic vessels.
• Damage to gland cells with purulent or inflammatory processes.
• The development of oncological diseases.
• Various mechanical damage.
• Damage to the bile ducts.
• Pathological or abnormal changes in the liver.
• Complex ailments of an infectious type.
• Structural violation of organ tissues that can provoke liver failure, cirrhosis.
• Diseases caused by exposure to autoimmune viruses.

It is worth noting that any of the above ailments will be accompanied by liver failure and soreness, and this is fraught with cirrhosis.

Symptoms

The coordinated work of many body systems directly depends on what functions the liver performs. If this organ is damaged, then this is fraught with serious consequences. Most often, people suffer from diseases of the stomach, pancreas and other organs. If you do not apply in a timely manner qualified help physicians, the quality of human life may deteriorate.

Experts recommend following a few rules. The liver will perform all the functions only if a person can identify the disease in the early stages and get rid of it. All pathologies of this glandular organ at the primary stage are manifested by standard symptoms:

• Liquid stool.
• acute pain in the liver area, indicating an increase in the organ and the presence of viral hepatitis.
• A small rash on the face or chest.
• Changes in skin and eye color (characteristic yellow).
• Well-marked vascular problems.

If at least one symptom appears, you should immediately consult a doctor. Only after a thorough examination and passing all the tests, the specialist will be able to determine the exact diagnosis.

Preventive methods

In order for the liver to perform all the functions for the normal functioning of the digestive tract, you need to follow a few elementary recommendations. Hereby healing properties has a balanced diet: the patient must completely exclude from his diet fried, fatty, smoked, salty, too sweet and alcohol. Be sure to eat fresh fruits and vegetables. It is advisable to replace butter with vegetable or olive oil. You need to drink at least a liter of pure non-carbonated water per day.

The liver performs better if a person consumes fresh juices daily. You can use medicines only after the appointment of a specialist. Only after consulting a doctor, you can resort to effective recipes traditional medicine. Thanks to this, you can cleanse the liver. Yoga classes also have a positive effect on the body.

Adverse factors

The value of the liver for a full human life is simply priceless. But this body is very sensitive to various adverse factors. Numerous studies have shown that iron suffers most from the following factors:

Prolonged exposure to one or more of the above factors leads to dysfunction of the organ. If the patient neglects timely treatment, then the death of liver cells is simply inevitable, such an attitude to health will end with hepatitis or cirrhosis.

Regenerative Capabilities

Few citizens thought about the importance of each organ. The liver performs numerous functions, on which not only the well-being of a person depends, but also the performance of all other body systems. But until serious health problems appear, preventive measures are most often forgotten.

The liver has unique property: it is capable of regeneration, even if the specialists managed to save only 20-25% of the entire share. There is a lot of information in medical reference books that after resection (removal of the diseased area), the restoration of the original size of the organ was repeatedly observed. Of course, this process is quite slow, as it can take from two months to several years. It all depends on the age and lifestyle of a particular person.

The liver often reacts to excess and lack of size. Qualified doctors have repeatedly observed patients who underwent transplantation of a donor organ. It is considered interesting that after the recovery of the patient's native gland and restoration to the desired size, the donor part gradually atrophied. Of course, even numerous studies could not fully explain all the features of regeneration. But recovery always occurs only after healthy liver cells begin to divide. It is considered surprising that after the removal of 90% of the affected tissue, the reproduction of hepatocytes is simply impossible. If less than 40% of the organ was resected, then there will be no cell division either.