Hepatobiliary system. Hepatobiliary system diseases

The hepatobiliary system is a complex multilevel mechanism that allows for the implementation of 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 the immune response and antimicrobial protection.

Hepatobiliary system organs

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

Bile, its functions in the body

The functions of bile, which include electrolytes dissolved in water, 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 enzymes of the intestine and pancreas, 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 biliary excretion, affecting the motor and secretory functions of the small intestine. It participates in the inactivation of peptin and hydrochloric acid, which are part of the gastric juice, stimulates proliferation (proliferation) and desquamation of intestinal epithelial cells, and affects the secretion of mucus. In addition, it is involved in the neutralization of various toxic and medicinal substances.

Liver

The anatomy of the hepatobiliary system considers the liver not only as the central organ of bile formation, but also as the most important human organ. It is here that the majority of the energy of the body is formed, because 20% of the mass of the cells that make up the liver is occupied by mitochondria synthesizing 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 drugs. The liver belongs to one of the few organs that are constantly exposed to serious stress, but at the same time are able to recover independently in a short time. In the body, it performs the following functions:

• bile formation and biliary excretion;
• metabolic - in addition to the synthesis of many substances (proteins, cholesterol, glycogen, urea) necessary for the normal functioning of the digestive tract, the liver regulates water metabolism and the exchange of amino acids and proteins, carbohydrates, fats and biologically active substances;
• depositing - the liver is a kind of pantry, where proteins, carbohydrates, fats, vitamins, hormones, minerals accumulate;
• barrier - here, foreign and toxic compounds that enter the body with food or are formed in the intestine are neutralized;
• excretory - the liver is able to remove toxic substances that enter it into the bile, which, due to its composition, removes them from the body;
• homeostatic - synthesis, accumulation and splitting of blood plasma components, in particular, immunoglobulins, components of the coagulation system, occur in the liver.

Causes of damage to the hepatobiliary system

Dysfunction of the hepatobiliary system, in particular, the liver, most often results from the action of aggressive compounds. These include the effects of poisons, bacterial and viral lesions, free radicals. Also, the hepatobiliary system can suffer due to various hormonal and metabolic disorders, poor nutrition, uncontrolled medication, and alcohol abuse. Stress can also be important in the occurrence of various pathologies.

Types of damage to the hepatobiliary system

Modern medicine distinguishes the following types of lesions that cause a violation of the hepatobiliary system:

• Mitochondrial - these lesions develop at the cellular level and consist in a partial blockade of the respiratory chain enzymes . Most often, they become the result of the use of antibiotics (tetracyclines), antiretroviral drugs, parenteral nutrition. Fibrosis becomes a manifestation of such lesions, sometimes proliferation of the bile ducts is possible.
• Protein dystrophy occurs due to impaired protein synthesis. Most often, such lesions result from prolonged toxic effects (alcohol, drugs, viral and bacterial lesions, poisons).
• Fibrosis develops due to drug damage. Most often they are caused by cytostatic drugs. It is manifested by the growth of fibrous tissue, which, disrupting blood flow, causes an increase in pressure in the portal vein and disrupts the functioning of liver cells.
• Cholestasis - a decrease in the amount of bile entering the duodenum, or its absence. 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 occur at different levels of her circulatory network, ranging from capillaries to lesions in the blood vessels of the arterial bed and the portal vein system.
• Thickening of bile - this pathology of the hepatobiliary system most often develops due to blockage of the bile ducts by mucous or bile plugs. 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 non-specific symptoms. Non-specific symptoms include intoxication, manifested by lethargy, fatigue, weakness and fever during periods of exacerbation of the disease. They are associated with a decrease in detoxification function of the liver, the possible reverse absorption of bile or disorders in protein, carbohydrate or vitamin metabolism. Specific symptoms include those manifestations 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);
• abdominal pains “under the stomach” or localized on the right, usually arising after ingestion of oily or smoked foods;
• skin manifestations (spider veins, xanthomas, pigmentation disorder, jaundice);
• ascites - accumulation of fluid in the abdominal cavity;
• strengthening the venous pattern on the abdomen;
• the presence of hepatic odor from the mouth.

Disorders of the hepatobiliary system in children

The hepatobiliary system in children is much less likely than in adults to undergo inflammatory processes caused by infectious factors. More often, its pathologies are associated with functional disorders. They can be diagnosed in children of different ages, but most often they suffer from schoolchildren. This is due to an increase in mental, emotional and physical stress, as well as a change in diet. Important in the occurrence of functional disorders is enhanced growth and hormonal changes in the body of the child. Most often during this period, biliary dyskinesia is diagnosed, less often cholecystocholangitis and cholecystitis.

It is customary to distinguish primary and secondary lesions of the hepatobiliary system. Primary lesions can be associated both with the anatomical pathologies of the biliary tract, and with defects in the sphincters that regulate 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 successes of modern hepatology, there is an increase in various lesions of the biliary tract and their tendency to chronicity and a long, protracted course, so timely diagnosis becomes a paramount task. In addition to examination, history taking and laboratory tests, the most informative of which can be considered blood biochemistry, the following methods for studying the hepatobiliary system help determine the functional state .

1. Computed tomography - more often performed to monitor the biopsy of the tissues of the abdominal organs, the most informative with the intravenous administration of contrast agents.
2. MRI - allows you to effectively identify various lesions of the tissues of the liver and cysts, allows you to examine and detect vascular changes in cancer processes.
3. Radionuclide scanning - allows you to evaluate the excretion of bile and various changes in the tissues of the liver, identify tumor processes, foci of inflammation and assess the patency of the bile ducts.
4. Cholangiography reveals stones and tumors in the bile ducts, as well as the presence of fistulas and other pathologies of the biliary tract. In addition, this examination allows you to take samples of bile and epithelium of the bile ducts, as well as insert a catheter and drain the bile, expand the bile ducts and introduce drugs that dissolve calculi (gallstones).
5. Angiography allows you to evaluate blood flow in the portal and hepatic veins. It is crucial in the differential diagnosis of cancer of the liver.
6. Ultrasound of the organs of the hepatobiliary system is the most simple, affordable and informative research method. It allows you to identify stones in the gallbladder and bile ducts, optimally for the detection of ascites.

Ultrasound of the hepatobiliary system

The preparation required for this study is quite simple, but necessary to get the full picture. Its goal is to minimize the amount of gas in the intestine so that the intestinal loops do not obscure the view of the organs under investigation. To do this, on the eve of the examination, you need to conduct a cleansing enema or take a laxative. In order for the procedure to be as effective as possible, three days before it is necessary to follow a diet that reduces the process of gas formation. Examination should be carried out on an empty stomach, at least 8 hours should pass from the time of the last meal.

Diet before ultrasound

When conducting an ultrasound of the organs of the hepatobiliary system, the preparation must necessarily include, in addition to cleaning procedures, a diet that reduces gas formation. Here are its principles:

• Food should be fractional - 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, sodas or spirits.

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