Hepatobiliary system. Diseases of the hepatobiliary system

Hepatobiliary system is a complex multi-level mechanism that allows to carry out such important processes as digestion and excretion (excretion of metabolic products from the body). The result of its damage is a violation of metabolic processes, detoxification processes, as well as immune response and antimicrobial protection.

Organs of the hepatobiliary system

The hepatobiliary system is made up of the gallbladder, liver and bile ducts. Its main task is the formation and transportation of bile, which is produced by the cells of the liver. On the ducts, it moves into the gallbladder, which is an additional reservoir. The bile accumulating in it is more concentrated than the hepatic 5-10 times. After eating, it enters the lumen of the duodenum. The anatomy of the hepatobiliary system in addition to the liver and gallbladder includes intrahepatic bile ducts, which are located directly in the liver. They, starting as bile capillaries, gradually pass into larger bile ducts, which go beyond the liver. Extrahepatic bile ducts are represented by the common hepatic and general vesicle, which, when combined, form a common bile duct.

Bile, its functions in the body

Functions of bile, which includes dissolved in water electrolytes, heavy metals (copper) and organic substances (bile salts and acids, cholesterol, bilirubin and many others) are very diverse. First of all, it participates in the emulsification of fats, and also enhances the hydrolysis and absorption of proteins and carbohydrates. Bile is a catalyst for the activity of the intestinal and pancreatic enzymes, thereby stimulating the process of digestion and absorption of fats and vitamins A, D, E, K.

In addition to the secretory function, bile in the body also plays a regulatory role, controlling bile formation and bile excretion, affecting the motor and secretory functions of the small intestine. It is involved in the inactivation of peptin and hydrochloric acid, which are part of the gastric juice, stimulates the proliferation (proliferation) and slushing of epithelial cells of the intestine, affects the secretion of mucus. In addition, it is involved in the neutralization of various toxic and medicinal substances.

Liver

Anatomy of the hepatobiliary system treats the liver not only as the central organ of bile formation, but also as the most important organ of man. It is here that most of the energy of the body is formed, because 20% of the mass of cells that make up the liver occupy the mitochondria that synthesize ATP. The liver is the largest gland in the human body, which ensures the constancy of the internal environment of the body. She has a central role in protein, fat and carbon metabolism, as well as in the metabolism of medicinal substances. The liver is one of the few organs that are constantly subjected to serious stress, but at the same time are able to restore themselves in a short time. In the body, it performs the following functions:

• Bile formation and bile excretion;
• Metabolic - in addition to the synthesis of many substances (proteins, cholesterol, glycogen, urea) required for the normal functioning of the gastrointestinal tract, regulation of water metabolism and metabolism of amino acids and proteins, carbohydrates, fats and biologically active substances takes place in the liver;
• Depositing - the liver is a kind of pantry, where proteins, carbohydrates, fats, vitamins, hormones, minerals accumulate;
• Barrier - here are neutralized foreign and toxic compounds that enter the body with food or formed in the intestine;
• Excretory - the liver is able to remove toxic substances that have entered into it into the bile, which, due to its composition, removes them from the body;
• Homeostatic - the synthesis, accumulation and splitting of blood plasma components, in particular, immunoglobulins, components of the coagulation system, takes place in the liver.

The causes of defeat of the hepatobiliary system

Dysfunction of the hepatobiliary system, in particular, the liver, is most often the result of the action of aggressive compounds. These include the effects of poisons, bacterial and viral lesions, free radicals. Also, the hepatobiliary system may suffer due to various hormonal and metabolic disorders, malnutrition, uncontrolled intake of drugs, alcohol abuse. Stresses can also be of great importance in the occurrence of various pathologies.

Types of lesions of the hepatobiliary system

Modern medicine distinguishes the following types of lesions, causing a violation of the hepatobiliary system:

• Mitochondrial - these lesions develop at the cellular level and are a partial blockade of the respiratory chain enzymes . Most often they are the result of the use of antibiotics (tetracyclines), antiretroviral drugs, parenteral nutrition. Manifestations of such lesions become fibrosis, sometimes proliferation of the bile ducts.
• Protein dystrophy occurs due to a violation of protein synthesis. Most often, these lesions are the result of prolonged toxic effects (alcohol, drugs, viral and bacterial lesions, poisons).
• Fibrosis develops as a result of medicinal lesions. Most often they are caused by cytotoxic drugs. It manifests itself in the growth of fibrous tissue, which, violating the blood flow, causes an increase in pressure in the portal vein and disrupts the functioning of the liver cells.
• Cholestasis is a decrease in the amount of bile entering the duodenum or lack of it. The cause of this may be a mechanical obstruction (stones in the gallbladder) or disorders that occur at the level of liver cells and intrahepatic bile ducts.
• Vascular lesions - can manifest themselves at different levels of its circulatory network, beginning from the capillaries and ending with the damage to the vessels of the arterial bed and the portal vein system.
• Congestion of bile - this pathology of the hepatobiliary system most often develops as a result of plugging of the bile ducts with mucous or bilious corks. Most often, it occurs in newborns and is associated with a Rh factor conflict.

Symptoms

Diseases of the hepatobiliary system, as a rule, have specific and nonspecific symptoms. Nonspecific symptoms include intoxication, manifested by lethargy, fatigue, weakness and fever during periods of exacerbation of the disease. They are associated with a decrease in the detoxification function of the liver, possible back absorption of bile or disorders in protein, carbohydrate, or vitamin metabolism. Specific symptoms include those that occur when the hepatobiliary system is directly affected. These include:

• Various digestive disorders (nausea, heaviness in the right hypochondrium, less often vomiting caused by food provocation, diarrhea);
• Pain in the abdomen "under the pit of the stomach" or localized on the right, usually arising after the reception of fatty or smoked food;
• Skin manifestations (vascular sprouts, xanthomas, pigmentation disorders, jaundice);
• Ascites - accumulation in the abdominal cavity of fluid;
• Reinforcement of the venous pattern on the abdomen;
• Presence of liver odor from the mouth.

Violations of the hepatobiliary system in children

Hepatobiliary system in children is much less likely than in adults to undergo inflammatory processes caused by infectious factors. Much more often, its pathology is associated with functional disorders. They can be diagnosed in children of different ages, but most often they suffer from schoolchildren. This is due to increased mental, emotional and physical loads, as well as changes in diet. Important in the emergence of functional disorders has increased growth and hormonal changes in the child's body. Most often during this period, dyskinesias of the biliary tract are diagnosed , less often - cholecystocholangitis and cholecystitis.

It is customary to isolate primary and secondary lesions of the hepatobiliary system. Primary lesions can be related to both the anatomical pathologies of the biliary tract and the defects of the sphincters regulating the movement of bile, in particular, the sphincter of Oddi. Secondary dysfunctions can occur with the following pathologies:

• Gastroduodenal (peptic ulcer, duodenitis);
• Pathology of the pancreas;
• Metabolic disorders;
• Parasitic diseases.

Diagnostics

Despite the significant success of modern hepatology, there is an increase in various lesions of the biliary tract and their tendency to chronic and long, prolonged flow, so timely diagnosis becomes a priority. In addition to examining, collecting anamnesis and laboratory studies, the most informative of which can be considered blood biochemistry, the following methods of investigation of the hepatobiliary system help determine the functional state .

1. Computer tomography - is more often performed to control the biopsy of tissues of the abdominal cavity, the most informative for intravenous administration of contrast agents.
2. MRI - allows you to effectively detect various lesions of liver tissues and cysts, allows you to examine and identify vascular changes in cancer processes.
3. Radionuclide scanning - allows to evaluate bile excretion and various changes in liver tissues, reveal tumor processes, inflammation foci and assess patency of the bile ducts.
4. Cholangiography can detect stones and tumors in the bile ducts, as well as the presence of fistulas and other pathologies of the bile duct. In addition, this examination allows you to take samples of bile and epithelium of the bile ducts, and also insert a catheter and drain the bile, expand the bile ducts and introduce drugs that dissolve the stones (gallstones).
5. Angiography allows you to assess the blood flow in the portal and liver veins. It is of decisive importance in the differential diagnosis of oncological lesions of the liver.
6. Ultrasound of the hepatobiliary system is the simplest, most accessible and informative method of investigation. It allows you to identify the stones in the gallbladder and bile ducts, optimally for ascites.

Ultrasound of the hepatobiliary system

The preparation that is required for this study is fairly simple, but necessary to get the full picture. Its goal is to minimize the amount of gases in the intestine so that the intestinal loops do not cover the survey of the organs being examined. For this, on the eve of the examination, it is necessary to perform a cleansing enema or take a laxative. For the procedure to be as effective as possible, three days before the procedure it is necessary to observe a diet that reduces the process of gas formation. The examination should be performed on an empty stomach, since the last meal should take at least 8 hours.

Diet before ultrasound examination

When performing ultrasound of organs of the hepatobiliary system, preparation must necessarily include, in addition to cleansing procedures, a diet that reduces gas production. Here are its principles:

• Food should be divided - at least four times a day, and the last meal should be at least 2 hours before bedtime.
• The volume of liquid must be reduced to one and a half liters.
• Exclude from the diet products that include yeast, fatty meat or fish, legumes, sugar, strong tea or coffee, carbonated or alcoholic beverages.

Hepatobiliary system performs many important functions in the human body, and timely detected violations in its work will help to avoid many problems in the future.