Where is the liver located?

The location of the liver in the abdomen, on the path between the intestines, where food is digested and absorbed, and the rest of the body sheds some light on its function. It is no coincidence that all the blood flowing from the abdominal organs flows into a powerful venous collector - the portal vein. This blood carries, as you know, nutrients that are broken down during digestion, and, before entering the general circulation, passes through the liver.

Liver function

The liver is wedge-shaped. It is the largest and, in a sense, the most complex organ. One of its main functions is the destruction of harmful substances absorbed from the intestines or formed in other parts of the body. The liver removes them in the form of safe metabolic products along with bile or excretes them into the blood. Metabolic products along with bile enter the intestines, and then are removed from the body with feces. Those that enter the bloodstream are filtered by the kidneys and excreted in the urine.

The liver produces almost half of the cholesterol the body needs, and the rest comes from food. About 80% of this component, synthesized by the liver, is used in the production of bile. Cholesterol is an essential part of cell membranes and is also needed for the synthesis of several hormones, including estrogens, testosterone, and adrenal hormones.

Substances formed as a result of the digestion of food, the liver converts into proteins, fats and carbohydrates. It is in the liver that sugar is deposited in the form of glycogen. As needed (for example, when blood sugar gets too low), it is broken down, converted into glucose, and released into the bloodstream.

The functions of the liver include the synthesis of many important compounds necessary for the vital activity of the body, in particular, proteins. The liver produces substances that are involved in the formation of a blood clot when bleeding occurs. These are called blood clotting factors.

Blood flows to the liver from the intestines and from the heart. The smallest capillaries in the intestinal wall open into veins that drain into the portal (portal) vein, which carries blood to the liver. Inside the liver, the portal vein splits back into capillaries and travels through a network of tiny canals. They are formed by the liver cells, where digested nutrients and all unhealthy foods are processed. The blood from the heart is carried to the liver by the hepatic artery. This blood supplies oxygen to the liver tissue, as well as cholesterol and a number of other substances that are processed by the liver. Blood from the intestines and heart then mixes and flows back to the heart through the hepatic veins.

Liver functions in the human body

As many functions as the liver performs, not a single organ in the human body provides. These include:

Detoxification of the body - neutralization of all toxic compounds that enter the bloodstream from the environment (alcohol, toxins, medicines);

Utilization and inactivation of toxic metabolic products formed in the body during vital activity (protein breakdown products, phenol, ketone compounds and acetone);

Participation in vitamin and mineral metabolism: depositing water-soluble vitamins of group B, C, PP, as well as fat-soluble D, E, K, trace elements of iron, copper and cobalt;

Participation in the synthesis of steroid sex, thyroid, adrenal hormones and the neutralization of their excess;

Regulation of carbohydrate metabolism;

Deposition and distribution of energy substrates in the body (glucose, glycogen) through the processes of glycogenolysis, gluconeogenesis, glycolysis;

Participation in lipid metabolism (metabolism of cholesterol, phospholipids, fatty acids, lipoproteins);

Implementation of the central processes of protein metabolism: synthesis of protein components for cell membranes and transport proteins, redistribution of amino acids;

Participation in the synthesis of immunogobullins, antibodies and other important proteins of the immune system;

Synthesis of plasma coagulation factors and blood anticoagulation system;

Hematopoiesis function, especially in the prenatal and childhood period;

Synthesis of bile and enzymes that are involved in digestion processes. Their main role is the breakdown of fats;

Implementation of bilirubin metabolism and its neutralization by conjugation with glucuronic acid;

Deposition of blood, which makes it possible to redistribute it in case of need (release of blood into the vessels in case of its deficiency during blood loss or concentration in case of congestive heart failure);

The liver is the largest gland in the human body, which performs the most functions among all organs. Damage to the liver can be accompanied by a violation of one or all of its functions, which underlies the severity of the disease.

The group of hepatic diseases can include any types of damage to all structures that do not go beyond the anatomical limits of this organ. These can be hepatocytes and the hepatic lobules that they form, intrahepatic arterial and venous vessels, and bile ducts. Diseases of the extrahepatic bile ducts and gallbladder should be treated separately.

The main common liver diseases are shown in the table:

Group of liver diseases	Nosological units from the group
Primary inflammatory, purulent and functional lesion of hepatic cells	Viral hepatitis (A, B, C and other types); Toxic hepatitis; Hepatomegaly of unspecified origin (causeless enlargement of the liver); Fatty hepatosis (fatty degeneration of the liver); Alcoholic and non-alcoholic steatohepatosis; Tuberculous and syphilitic liver damage; Liver abscess (formation of a purulent cavity).
Traumatic injury	Liver ruptures with blunt closed abdominal trauma; Open liver damage (stab wounds); Gunshot injuries and crushing of the liver.
Vascular diseases	Hepatic vein thrombosis (Budd-Chiari syndrome); Pylephlebitis (purulent inflammation of the portal vein of the liver); Portal hypertension (increased pressure in the portal vein and portal system with cirrhosis of the liver); Intrahepatic arteriovenous fistulas and fistulas (pathological fistulas between the vessels of the liver).
Intrahepatic bile duct damage	Intrahepatic cholestasis (stagnation of bile in the liver); Acute cholangitis (purulent inflammation of the bile ducts); Chronic cholangitis; Intrahepatic cholelithiasis (formation of stones in the hepatic bile ducts); Caroli's disease (congenital enlargement of the intrahepatic ducts with increased stone formation and multiple small abscesses).
Tumor diseases	Liver cyst (limited fluid accumulation, limited by the capsule); Hemangioma (abnormal accumulation of vascular structures in the form of a tumor); Hepatocellular carcinoma; Angiosarcoma and other types of liver sarcomas; Intraductal cancer (Klatskin's tumor); Metastatic liver disease in cancer of any localization.
	Alveococcosis; Echinococcosis; Ascariasis; Opisthorchiasis; Leptospirosis.
Hereditary pathology and anomalies	Hypoplasia and aplasia of the liver (underdevelopment or absence of an organ); Atresia of the intrahepatic ducts and blood vessels (narrowing or membranes that obstruct the flow of blood or bile); Hepatic fermentopathy with impaired bilirubin metabolism (Gilbert, Rotor, Dabin-Jones syndromes); Hepatic fermentopathy with impaired copper metabolism (Wilson-Konovalov syndrome); Hemochromatosis; Hereditary pigmentary hepatosis.
Liver damage in pathology of other organs	Congestive liver with heart failure; Amyloidosis; Renal hepatic impairment; Hepatomegaly with leukemia.
Structural and functional rearrangements in the liver and their complications	Cirrhosis of the liver; Liver failure; Parenchymal jaundice; Hepatic coma.
Autoimmune liver disease	Pathology in which there is an unreasonable destruction of the liver by its own immune system: Autoimmune hepetitis; Primary sclerosing cholangitis; Primary biliary cirrhosis of the liver;

Any liver disease in case of progression ends with cirrhosis and is accompanied by one or another degree of hepatocellular insufficiency.

Liver disease symptoms Frequent nausea, heartburn, a very unpleasant, pungent odor of sweat, yellowish skin color, dark yellow urine, diarrhea, change in the color of feces to dark brown or light yellow, sometimes green, are considered.

Liver disorders can also lead to acne in adulthood, frequent hunger or intense and frequent thirst, itching of some thin areas of the skin, and blurred vision. For example, a person may begin to confuse white with yellow, feel cold and hot, not sleep at night, while experiencing fever, palpitations. Hair and eyebrows may begin to fall out. Convulsions occur, papillomas are formed, the development of atherosclerosis of the brain, heart, intestines, vessels of the legs begins.

Typical cases of organic and functional liver problems are easily recognized by their characteristic symptoms. But some situations create difficulties for the correct diagnosis, even for experienced hepatologists (specialists dealing with liver diseases). It all depends on the specific type of disease, the individual characteristics of the organism, the presence or absence of concomitant pathology.

The main clinical manifestations of hepatic pathology can be:

Discomfort and pain in the projection of the liver;

Enlargement of the liver in size;

General weakness and malaise;

Headache;

Impaired mental and cognitive abilities;

Increased skin sweating and swelling;

Yellowness of the skin and sclera;

Skin rash;

Severe itching of the skin;

Increased fragility of blood vessels and a tendency to bleed;

Signs of hypovitaminosis;

Stool instability, change in the nature and color of feces;

An increase in the size of the abdomen;

Reinforced venous pattern on the skin of the abdomen;

Unmotivated weight loss;

Bitterness in the mouth;

Mother-in-law on the surface of the tongue and its coating with white or brown bloom;

Temperature reaction of varying severity.

How does the liver hurt?

Pain in liver damage can be of a different nature. They can be interpreted as follows:

Slight pain in the right hypochondrium in the form of aching pain, distention and heaviness. They characterize a sluggish pathological process of inflammatory toxic or other origin. This type of pain in the liver is most likely due to an increase in the size of the organ and an overstretching of the hepatic capsule. Patients cannot clearly indicate one pain point;

Intense widespread pain in the right hypochondrium. They are rare and speak either of a pronounced inflammatory, purulent, traumatic pathological process, or of damage to the bile ducts with stones;

Severe local punctate pain in the projection of the liver. It is not typical for liver damage and in most cases is associated with pathology of the gallbladder and extrahepatic bile ducts;

Complete absence of pain in the liver. It is very common in sluggish liver diseases that go unnoticed for a long time and are determined only at the stage of liver failure or liver cirrhosis.

According to the characteristics of the skin, one can determine the functioning of various organs, including the liver.

With such diseases, the skin can be:

Pale or swarthy with severe sweating and swelling of the subcutaneous tissue, especially in the face and limbs;

Dry, scaly with multiple scratches and cracks;

Prone to allergic rashes, atopic dermatitis, psoriasis, eczema;

Jaundice. By the nature of this type of skin changes, you can determine the origin of jaundice. In case of liver problems, yellowness is of moderate intensity and is represented by an orange tint. When carrying out the differential diagnosis of jaundice, this criterion makes it possible to exclude their mechanical types (brown skin tone) and hemolytic, accompanied by a lemon-yellow skin tone;

With striae. Stretch marks are stretch marks of the skin, mostly of the abdomen, in the form of cyanotic stripes of its thinning. The reason for their appearance is hormonal imbalance, both in the male and female body, when the liver is unable to neutralize excess steroid hormones.

Rash with liver disease

In most patients with liver pathology, along with a change in skin color, the appearance of various rashes is noted.

The mechanisms of occurrence and types of rash can be as follows:

Pustular elements, tendency to folliculitis and furunculosis. They are based on an immune imbalance that occurs against the background of a decrease in the liver's ability to synthesize immunoglobulins;

• What causes gallstone disease?

  The professor in his arms shows in the video the reasons for the development of the disease in the gallbladder. Causes of pancreatic pain. And he connects this with delicate motor skills. Treatment as such is not needed. If you start motility, the gallbladder itself will dissolve its stones.

  Video about gallstone disease

  How to heal the liver home methods?

  Baths for liver disease:
  Warm baths with decoctions have a very beneficial effect on the sick body. Prepare them like this. Take 50g of any of the herbs: wild rosemary, wormwood or juniper, pour one liter of water and boil for 30 minutes. The broth is filtered into a bath and sit in it for 20-30 minutes, no more. The course of admission is 3 weeks in three days. Such baths reduce body temperature, relieve fatigue, joint pain and exacerbation of liver disease. After the bath, it is recommended to drink hot milk or some dry natural red wine.

  
  Oats for liver disease:
  You can buy oats at your local drugstore or pet store. Take 2 tablespoons of unpeeled oats and pour 1 liter of water, boil for 15-20 minutes over low heat, then add 2 tablespoons of milk (preferably goat's) and boil for another 5 minutes. Strain the broth and add 2 tablespoons of honey. Take 1/3 cup 3 times daily 30 minutes before meals. The course of treatment is two weeks. Thanks to this folk remedy, a large amount of bile will be thrown out.

  
  Herbal decoctions for liver disease:
  Traditional medicine recommends taking decoctions of yellow herbs. Take any herb: tansy, St. John's wort, chamomile, immortelle, milk thistle in a ratio of 1 tablespoon to a glass of boiling water. Boil over low heat for 1-2 minutes, strain and take 3 times a day, 1/3 cup 30 minutes before meals. Before going to bed, it is useful to take decoctions of motherwort, mint St. John's wort. They relieve irritability, promote restful sleep. You can buy alcoholic tinctures of these herbs at the pharmacy. Take 10 drops of each herb tincture and fill with a glass of warm water. Take one hour before bed for 10 days.

  
  Corn fiber for liver disease:

  If you pluck the leaves off a corncob, you will see a lot of hairs or fibers underneath. For successful treatment, pick only ripe ears. Unripe - have no healing power. Take these fibers and pour boiling water, after 30-40 minutes take the infusion. You can add honey. Take twice a day for 1 glass of infusion before meals. The duration of the infusion can be up to six months. The longer the period of the infusion, the more useful qualities it contains.

  Grapefruit juice and olive oil for liver disease:

  If you begin to feel pain in the right hypochondrium, then, most likely, this is a signal from the liver. Don't forget that it requires constant liver cleansing. A good remedy in this case would be a mixture of a quarter cup of olive oil with a quarter cup of grapefruit juice. You need to take at night, not earlier than 2 hours after a meal. Be sure to do an enema before this. Lie on your right side in bed. It is recommended to do the enema again in the morning. Do this procedure after four to five days and after a month you will feel the result.

The liver in humans is located below the diaphragm, occupies the right hypochondrium, epigastric and a site of the left hypochondrium.

The human liver has a soft consistency, but a dense structure due to the connective tissue sheath covering it called the glisson capsule and the many connective tissue septa extending deep into the organ.

Outside, the organ is surrounded by the peritoneum, with the exception of a separate area of ​​small size at the back, tightly adjacent to the diaphragm. At the junction of the peritoneum with the organ, folds are formed that play the role of ligaments. Ligaments of the human liver provide fixation, primarily to the diaphragm, some provide communication with neighboring organs and the anterior abdominal wall. The largest of them is sickle-shaped, dividing the organ in the sagittal plane into two largest lobes - right and left. The location of the human liver is stable due to these supporting ligaments.

In the anatomy of the human liver, there are lower (visceral, it is slightly concave) and upper (diaphragmatic, convex) surfaces, two edges, three grooves.

The lower surface deserves a separate mention. The grooves located there divide the right lobe additionally into caudate and square. In the sagittal grooves are the gallbladder (in the right) and the round ligament (anterior left). In the transverse groove (connects the sagittal ones) is the most important structure - the gate of the liver.

The anatomy of the structure of the human liver is such that all its elements (vessels, ducts, lobules) are connected with neighboring similar structures and undergo transformations in a radial order: small ones merge, combine into larger ones, and, conversely, large ones are divided into smaller ones.

So, the smallest structural and functional elements of the liver - hepatic lobules - combine with each other, forming segments (there are 8 of them), then sectors (5), and as a result - two main lobes.

The hepatic lobules are separated by connective tissue septa with the vessels passing there and the bile duct, called interlobular. The lobule itself is prismatic and contains a group of hepatic cells (hepatocytes), which are simultaneously the walls of the smallest bile ducts, capillaries and a central vein. In the lobules, both bile formation and the exchange of nutrients occur.

Further formation of the biliary tract occurs according to the same ascending principle: the ducts pass into the interlobular ducts, from which the right and left hepatic ducts are formed, are combined into a common hepatic. The latter, after exiting through the gate of the liver, connects with the duct of the gallbladder, and the common bile duct thus formed goes into the duodenum.

Human anatomy and the location of the liver interact so that normally the organ does not go beyond the costal arch, adjacent to such organs as the esophagus (abdominal), aorta, 10-11 thoracic vertebrae, right kidney with adrenal gland, stomach, right part of the colon, the upper part of the duodenum.

The blood supply to the liver in human anatomy has some peculiarities. Most of the blood entering the organ is venous from the portal vein (approximately 2/3 of the blood flow), the smaller part is arterial blood delivered through the common hepatic artery (a branch of the abdominal aorta). Such a distribution of blood flow contributes to the rapid neutralization of toxins coming from the remaining unpaired organs of the abdominal cavity (the outflow of blood from them is carried out into the portal vein system).

The blood vessels entering the liver undergo a traditional division in decreasing order. Within the hepatic lobule, both arterial and venous blood are present due to the junction of arterial and venous capillaries, which eventually flow into the central vein. The latter emerge from the hepatic lobules and eventually form 2-3 common hepatic veins that flow into the inferior vena cava.

A distinctive feature of the venous vessels of the liver in anatomy is also the presence of numerous anastomoses between the portal vein and adjacent organs: esophagus, stomach, anterior abdominal wall, hemorrhoidal veins, and inferior vena cava. The venous blood supply to the liver in humans is such that during venous stasis in the portal vein system, outflow along the collaterals is activated, and this has a number of clinical manifestations.

LIVER FUNCTIONS

The main function of the liver in the human body is detoxification (neutralizing). But other functions are also important, since they affect the work of almost all organs and the body as a whole.

Main functions:

• detoxification: substances entering the blood from the intestines (after the completion of the process of digesting food) and other organs of the abdominal cavity, as well as from the external environment, are toxic, and hepatocytes, using a number of biochemical reactions, convert them into final products that are low-toxic for the body (urea, creatinine ), a number of hormones and biologically active substances are also deactivated;
• digestive - the breakdown of fats due to the production of bile;
• metabolic: the liver takes part in all types of metabolism;
• excretory (excretory) - the production of bile and its secretion, due to which a number of metabolic products (bilirubin and its derivatives, excess cholesterol) are excreted;
• immune;
• hemodynamic: filtration through the portal vein of blood from the abdominal organs, depositing up to 700 ml of blood turned off from the bloodstream (in case of blood loss and other critical situations, it enters the bloodstream).

Features of participation in metabolic processes:

Carbohydrate metabolism: maintaining a constant level of blood glucose due to its accumulation in the liver in the form of glycogen. Violation of this function - hypoglycemia, hypoglycemic coma.

Fat metabolism: the breakdown of food fats by bile, the formation and metabolism of cholesterol, bile acids.

Protein metabolism: on the one hand, the liver is splitting and transforming amino acids, synthesizing new ones and their derivatives. For example, proteins are synthesized that participate in immune reactions, thrombus formation and blood coagulation (heparin, prothrombin, fibrinogen). On the other hand, the end products of protein metabolism are formed with their detoxification and excretion (ammonia, urea, uric acid). The consequence of these disorders is hemorrhagic syndrome (bleeding), edema (due to a decrease in the concentration of proteins in the plasma, its oncotic pressure increases).

Pigment metabolism: synthesis of bilirubin from expired, hemolyzed erythrocytes, conversion of this bilirubin and excretion with bile. Bilirubin, formed immediately after the destruction of red blood cells, is called indirect, or free. It is toxic to the brain, and in hepatocytes, after combining with glucuronic acid, it enters the bile and is called direct. Problems with pigment metabolism are manifested by jaundice, changes in the color of feces, and intoxication.

Exchange of vitamins, microelements: the liver accumulates vitamin B12, microelements (iron, zinc, copper), it forms biologically active forms of vitamins from their precursors (for example, B1), synthesis of some proteins with a specific function (transport).

LIVER DISEASES

The physiology of the liver is such that each of its functions listed above corresponds to many diseases, both congenital and acquired. They proceed in acute, subacute, chronic forms, and are manifested by a number of general symptoms.

Many diseases eventually lead to the development of hepatocellular failure, cirrhosis.

The main symptoms of liver disease:

• jaundice, that is, yellowness of the skin and visible mucous membranes. It happens as a result of increased destruction (hemolysis) of erythrocytes (hemolytic), impaired outflow of bile (mechanical, or obstructive), direct disturbance of the processes of conversion of bilirubin in the hepatocytes themselves (parenchymal);
• pain sensations: localized in the right hypochondrium, usually this is a feeling of heaviness or not intense, aching pain;
• asthenia (general weakness, fatigue);
• dyspeptic symptoms (bitterness in the mouth, nausea, vomiting, flatulence);
• discoloration of feces, red color of urine;
• skin manifestations: pruritus, dry skin, spider veins, pigmentation of physiological folds, redness of the palmar skin (palmar erythema, or "hepatic palms"), xanthomas (subcutaneous lumps with yellowish skin above them);
• ascites (the presence of free fluid in the abdominal cavity);
• "Liver" odor from the mouth: as a result of violations of protein metabolism (neutralization of its end products).

The most common diseases and pathological conditions:

• Viral hepatitis A, B, C. The viral agent directly infects hepatocytes. Type A hepatitis is the most easy, children are more likely to get sick, and is transmitted by the fecal-oral route. Viral hepatitis is manifested by jaundice, symptoms of intoxication. Subtypes B and C often lead to liver failure due to cirrhosis, the mode of infection is parenteral (through blood and other body fluids).
• Fatty hepatosis (fatty degeneration) - in hepatocytes excessively (exceeding the norm by many times) fats (triglycerides) accumulate, the process is focal or diffuse.
• Cirrhosis is a chronic inflammatory or degenerative process that occurs with fibrosis and restructuring of the normal structure of the organ.
• Hepatocellular failure. The consequence of the defeat of a significant number of hepatocytes by various pathogenic agents (poisonous substances, toxins, alcohol, some drugs, hepatitis viruses). At the same time, all the functions of the organ suffer, the syndrome of hepatocerebral insufficiency joins - headaches, sleep disturbances, psycho-emotional disorders with subsequent impairment of consciousness and the development of hepatic coma.
• Ascites. Accumulation of free fluid (transudate) in the abdominal cavity. A consequence of portal hypertension and a number of diseases not associated with the liver. A frequent companion of ascites of hepatic origin is bleeding from varicose veins of the esophagus, enlargement of the saphenous veins of the abdominal wall ("jellyfish head").

For liver problems, you may be helped by:

• gastroenterologist;
• hepatologist - a specialist in liver diseases;
• surgeon;
• oncologist;
• transplantologist;
• infectious disease specialist.

The stable functioning of the whole organism depends on the normal functioning of the liver, and, conversely, malfunctions in the work of other systems and organs, the influence of exogenous factors (infections, toxins, nutrition) can lead to problems with the liver, therefore you should be careful about your body as a whole, keep healthy lifestyle and promptly seek medical attention.

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A specialist in modeling acute and chronic poisoning, author and co-author of models of the most dangerous of the most common poisonings, created over ten years on the basis of clinical data (more than 400 cases) of the toxicological department of the 1st City Clinical Hospital, the Center for Extrarenal Methods of Cleansing the Body (Kazan) and information -Advisory toxicological center of the Ministry of Health of the Russian Federation (Moscow).

The expert of the section is also a gastroenterologist Purgina Daniela Sergeevna.

Daniela Sergeevna works at the Pasteur Research Institute of Epidemiology and Microbiology Medical Center. Engaged in the diagnosis and treatment of patients with a wide range of diseases of the gastrointestinal tract.

Education: 2014—2016 - Military Medical Academy. SM Kirov, residency in Gastroenterology; 2008—2014 - Military Medical Academy. SM Kirov, specialty "General Medicine".

The liver is an abdominal glandular organ in the digestive system. It is located in the upper right quadrant of the abdomen, below the diaphragm. The liver is a vital organ that supports just about any other organ to varying degrees.

The liver is the second largest organ in the body (skin is the largest organ), weighing about 1.4 kilograms. It has four lobes and a very soft texture, pink-brown color. It also contains several bile ducts. There are a number of important liver functions that will be discussed in this article.

The liver is an abdominal glandular organ in the digestive system

Physiology of the liver

The development of the human liver begins during the third week of pregnancy and reaches a mature architecture before the age of 15. It reaches its largest relative size, 10% of the weight of the fetus, around the ninth week. This is about 5% of the body weight of a healthy newborn. The liver makes up about 2% of the body weight in an adult. It weighs about 1400 g in an adult woman and about 1800 g in a man.

It is almost entirely behind the rib cage, but the lower edge can be felt along the right costal arch during inhalation. A layer of connective tissue called Glisson's capsule covers the surface of the liver. The capsule extends to all but the smallest vessels in the liver. The falciform ligament attaches the liver to the abdominal wall and diaphragm, dividing it into a large right lobe and a lesser left lobe.

In 1957, French surgeon Claude Cuinaud described 8 liver segments. Since then, an average of twenty segments have been described in radiographic studies based on the distribution of the blood supply. Each segment has its own independent vascular branches. The excretory function of the liver is represented by the bile branches.

What is each of the liver lobules responsible for? They serve arterial, venous and biliary vessels in the periphery. Human liver lobules have small connective tissue separating one lobule from another. Lack of connective tissue makes it difficult to determine the portal tracts and the boundaries of individual lobules. Central veins are easier to identify because of their large lumen and because they lack the connective tissue that envelops the portal triad vessels.

1. The role of the liver in the human body is varied and has more than 500 functions.
2. Helps maintain blood glucose and other chemical levels.
3. Bile secretion plays an important role in digestion and detoxification.

Due to its many functions, the liver is susceptible to rapid damage.

The liver plays an important role in the functioning of the body, detoxification, metabolism

What functions does the liver perform?

The liver plays an important role in the functioning of the body, detoxification, metabolism (including the regulation of glycogen storage), hormone regulation, protein synthesis, and the breakdown and degradation of red blood cells in short. The liver's main functions include producing bile, a chemical that breaks down fats and makes them more easily absorbed. It is responsible for the production and synthesis of several important elements in plasma, and also stores some vital nutrients, including vitamins (especially A, D, E, K and B-12) and iron. The liver's next function is to store simple sugar glucose and convert it into useful glucose if blood sugar drops. One of the liver's most famous functions is the detoxification system, which removes toxic substances from the blood such as alcohol and drugs. It also breaks down hemoglobin, insulin and keeps hormone levels in balance. In addition, it destroys old blood cells.

What other functions does the liver perform in the human body? The liver is vital for healthy metabolic function. It converts carbohydrates, lipids and proteins into nutrients such as glucose, cholesterol, phospholipids and lipoproteins, which are then used in various cells throughout the body. The liver breaks down the unusable portions of proteins and converts them into ammonia and ultimately urea.

Exchange

What is the metabolic function of the liver? It is an important metabolic organ and its metabolic function is controlled by insulin and other metabolic hormones. Glucose is converted to pyruvate via glycolysis in the cytoplasm, and pyruvate is then oxidized in mitochondria to generate ATP through the TCA cycle and oxidative phosphorylation. When fed, glycolytic products are used for the synthesis of fatty acids through lipogenesis. Long chain fatty acids are incorporated into triacylglycerol, phospholipids and / or cholesterol esters in hepatocytes. These complex lipids are stored in lipid droplets and membrane structures or are secreted into the circulation as low-density lipoprotein particles. In the starving state, the liver tends to release glucose through glycogenolysis and gluconeogenesis. During a short fast, hepatic gluconeogenesis is the main source of endogenous glucose production.

Hunger also promotes lipolysis in adipose tissue, which results in the release of non-esterified fatty acids, which are converted to ketone bodies in liver mitochondria despite β-oxidation and ketogenesis. Ketone bodies provide metabolic fuel for extrahepatic tissues. Based on human anatomy, the liver's energy metabolism is closely regulated by neural and hormonal signals. While the sympathetic system stimulates metabolism, the parasympathetic system suppresses hepatic gluconeogenesis. Insulin stimulates glycolysis and lipogenesis, but inhibits gluconeogenesis, and glucagon opposes the action of insulin. Numerous transcription factors and coactivators, including CREB, FOXO1, ChREBP, SREBP, PGC-1α, and CRTC2, control the expression of enzymes that catalyze key steps in metabolic pathways, thus controlling energy metabolism in the liver. Aberrant energy metabolism in the liver contributes to insulin resistance, diabetes and non-alcoholic fatty liver disease.

The liver's barrier function is to provide protection between the portal vein and systemic circulation

Protective

The liver's barrier function is to provide protection between the portal vein and systemic circulation. In the reticuloendothelial system, it is an effective barrier against infection. It also acts as a metabolic buffer between highly variable intestinal contents and portal blood, and tightly controls systemic circulation. By absorbing, storing and releasing glucose, fat and amino acids, the liver plays a vital role in homeostasis. It also stores and releases vitamins A, D and B12. Metabolizes or detoxifies most biologically active compounds absorbed from the intestine, such as drugs and bacterial toxins. Performs many of the same functions when injecting systemic blood from the hepatic artery, processing a total of 29% of cardiac output.

The protective function of the liver is to remove harmful substances (such as ammonia and toxins) from the blood, and then neutralize them or convert them into less harmful compounds. In addition, the liver converts most of the hormones and changes into other more or less active foods. The barrier role of the liver is represented by Kupffer cells, which absorb bacteria and other foreign substances from the blood.

Synthesis and cleavage

Most plasma proteins are synthesized and secreted by the liver, the most abundant of which is albumin. The mechanism of its synthesis and secretion has recently been presented in more detail. Polypeptide chain synthesis is initiated on free polyribosomes with methionine as the first amino acid. The next segment of the produced protein is rich in hydrophobic amino acids, which probably mediate the binding of albumin-synthesizing polyribosomes to the endoplasmic membrane. Albumin, called preproalbumin, is transported into the interior of the granular endoplasmic reticulum. Preproalbumin is reduced to proalbumin by hydrolytic cleavage of 18 amino acids from the N-terminus. Proalbumin is transported to the Golgi apparatus. Finally, it is converted to albumin just before being secreted into the bloodstream by removing six more N-terminal amino acids.

Some of the metabolic functions of the liver in the body perform protein synthesis. The liver is responsible for many different proteins. Endocrine proteins produced by the liver include angiotensinogen, thrombopoietin, and insulin-like growth factor I. In children, the liver is primarily responsible for heme synthesis. In adults, the bone marrow is not a device for the production of heme. However, the adult liver is responsible for 20% of heme synthesis. The liver plays a critical role in the production of almost all plasma proteins (albumin, alpha 1-acid glycoprotein, most of the coagulation cascade, and fibrinolytic pathways). Notable exceptions: gamma globulins, factor III, IV, VIII. Proteins produced by the liver: protein S, protein C, protein Z, plasminogen activator inhibitor, antithrombin III. Vitamin K-dependent proteins synthesized by the liver include: Factors II, VII, IX and X, protein S and C.

Endocrine

Every day, about 800-1000 ml of bile is secreted in the liver, which contains bile salts, which are necessary for the digestion of fats in the diet.

Bile is a medium for the excretion of certain metabolic wastes, drugs and toxic substances

Bile is also a medium for the excretion of certain metabolic wastes, drugs and toxic substances. From the liver, the canal system carries bile to the common bile duct, which is emptied into the duodenum of the small intestine and connected to the gallbladder, where it is concentrated and stored. The presence of fat in the duodenum stimulates the flow of bile from the gallbladder into the small intestine.

The endocrine functions of the human liver include the production of very important hormones:

• Insulin-like growth factor 1 (IGF-1). Growth hormone released from the pituitary gland binds to receptors on liver cells, causing them to synthesize and release IGF-1. IGF-1 has insulin-like effects because it can bind to the insulin receptor and is also a growth stimulus. Almost all cell types respond to IGF-1.
• Angiotensin. It is a precursor to angiotensin 1 and is part of the Renin-Angiotensin-Aldosterone system. It is converted to angiotensin by renin, which in turn is converted to other substrates that act to increase blood pressure during hypotension.
• Thrombopoietin. The negative feedback system works to keep this hormone at an appropriate level. Allows bone marrow progenitor cells to develop into megakaryocytes, platelet precursors.

Hematopoietic

What functions does the liver perform in the process of hematopoiesis? In mammals, shortly after liver progenitor cells invade the surrounding mesenchyme, the fetal liver is colonized by hematopoietic progenitor cells and temporarily becomes the main hematopoietic organ. Research in this area has shown that immature liver progenitor cells can generate an environment that supports hematopoiesis. However, when liver progenitor cells are induced to mature, the resulting cells can no longer support blood cell development, which is consistent with the movement of hematopoietic stem cells from fetal liver to adult bone marrow. These studies show that there is a dynamic interaction between blood and parenchymal compartments within the fetal liver, which controls the timing of both hepatogenesis and hematopoiesis.

Immunological

The liver is an important immunological organ with a high exposure to circulating antigens and endotoxins from the intestinal microbiota, especially enriched in innate immune cells (macrophages, innate lymphoid cells associated with the mucous membrane by invariant T cells). In homeostasis, many mechanisms provide suppression of immune responses, which leads to addiction (tolerance). Tolerance is also relevant for chronic resistance of hepatrotropic viruses or allograft intake after liver transplantation. The detoxifying function of the liver can quickly activate immunity in response to infection or tissue damage. Depending on the underlying liver disease, such as viral hepatitis, cholestasis, or non-alcoholic steatohepatitis, various triggers mediate immune cell activation.

Conservative mechanisms such as molecular hazard models, toll-like receptor signals, or activation of inflammation initiate inflammatory responses in the liver. Excitatory activation of hepatocellulose and Kupffer cells results in chemokine-mediated infiltration of neutrophils, monocytes, natural killer (NK) cells, and natural killer T (NKT) cells. The end result of an intrahepatic immune response to fibrosis depends on the functional diversity of macrophages and dendritic cells, but also on the balance between pro-inflammatory and anti-inflammatory T cell populations. The colossal advances in medicine have helped to understand the fine tuning of immune responses in the liver from homeostasis to disease, indicating promising targets for future treatments for acute and chronic liver disease.

Video

The structure and function of the liver.