The hepatobiliary system is a complex multi-level mechanism that allows for such important processes as digestion and excretion (removal 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 consists of the gallbladder, liver and bile ducts. Its main task is the formation and transportation of bile, which is produced by liver cells. Through the ducts, it moves to the gallbladder, which is an additional reservoir. The bile that accumulates in it is 5-10 times more concentrated than the hepatic one. After eating, it enters the lumen of the duodenum. The anatomy of the hepatobiliary system, in addition to the liver and gallbladder, includes the intrahepatic biliary tract, which are located directly inliver. They, starting as bile capillaries, gradually pass into larger bile ducts that extend beyond the liver. The extrahepatic bile ducts are represented by the common hepatic and common cystic ducts, which, when combined, form the common bile duct.
Bile, its functions in the body
The functions of bile, which includes electrolytes dissolved in water, heavy metals (copper) and organic substances (bile s alts and acids, cholesterol, bilirubin and many others), are very diverse. First of all, it is involved in the emulsification of fats, and also enhances the hydrolysis and absorption of proteins and carbohydrates. Bile is a catalyst for the activity of 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 also plays a regulatory role in the body, controlling bile formation and biliary 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 (growth) and desquamation of intestinal epithelial cells, 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 considers the liver not only as the central organ of bile formation, but also as the most important human organ. It is here that most of the energy of the body is formed, because 20% of the mass of cells,components of the liver are occupied by 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. It plays a central role in protein, fat and carbon metabolism, as well as in the metabolism of drugs. The liver is one of the few organs that are constantly subjected to serious stress, but at the same time they are able to recover on their own in a short time. In the body, it performs the following functions:
- biliary formation and biliary excretion;
- metabolic - in addition to the synthesis of many substances (proteins, cholesterol, glycogen, urea) necessary for the normal functioning of the gastrointestinal tract, the liver regulates water metabolism and the metabolism 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 - foreign and toxic compounds that enter the body with food or formed in the intestine are neutralized here;
- excretory - the liver is able to remove toxic substances that have entered it into bile, which, due to its composition, removes them from the body;
- homeostatic - synthesis, accumulation and breakdown 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, is most often the result of the action of aggressive compounds. These include exposure to poisons, bacterial and viral lesions, free radicals. Also, the hepatobiliary system can suffer due to various hormonal and metabolic disorders, poor nutrition, uncontrolled medication, alcohol abuse. Stress can also play an important role in the occurrence of various pathologies.
Types of lesions of 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 are the result of the use of antibiotics (tetracyclines), antiretroviral agents, parenteral nutrition. Fibrosis becomes a manifestation of such lesions, sometimes proliferation of the bile ducts is possible.
- Protein dystrophy occurs due to a violation of protein synthesis. Most often, such lesions are the result of long-term toxic effects (alcohol, drugs, viral and bacterial lesions, poisons).
- Fibrosis develops due to drug damage. Most often they are caused by cytotoxic 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 reason for this may be a mechanical obstruction (gallstones) or disorders that have arisen at the level of liver cells and intrahepatic bile ducts.
- Vascular lesions - can manifest themselves at different levels of her circulatory network, ranging from capillaries to damage to the vessels of the arterial bed and the portal vein system.
- Bile thickening - this pathology of the hepatobiliary system most often develops as a result of blockage of the bile ducts by mucous or bile plugs. Most often it occurs in newborns and is associated with a conflict in the Rh factor.
Symptoms
Diseases of the hepatobiliary system, as a rule, have specific and non-specific symptoms. Non-specific symptoms include intoxication symptoms, 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 reabsorption of bile or disturbances 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);
- pain in the abdomen "in the pit of the stomach" or localized on the right, usually occurring after takingfatty or smoked foods;
- skin manifestations (spider veins, xanthomas, pigmentation disorders, jaundice);
- ascites - accumulation of fluid in the abdominal cavity;
- strengthening of the venous pattern on the abdomen;
- presence of liver smell 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. Much more often, its pathologies are associated with functional disorders. They can be diagnosed in children of different ages, but most often they affect 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 child's body. Most often during this period, biliary dyskinesia is diagnosed, less often - cholecystocholangitis and cholecystitis.
It is customary to distinguish between primary and secondary lesions of the hepatobiliary system. Primary lesions can be associated both with 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.
Diagnosis
DespiteOn the significant advances 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 of studying the hepatobiliary system help determine the functional state.
- Computer tomography - more often performed to control the biopsy of the tissues of the abdominal organs, the most informative with intravenous administration of contrast agents.
- MRI - allows you to effectively detect various lesions of liver tissues and cysts, allows you to examine and detect vascular changes in oncological processes.
- Radionuclide scanning - allows you to evaluate the excretion of bile and various changes in the liver tissues, identify tumor processes, foci of inflammation and assess the patency of the bile ducts.
- Cholangiography can detect 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 bile duct epithelium, as well as insert a catheter and drain bile, dilate the bile ducts and administer drugs that dissolve stones (gallstones).
- Angiography measures blood flow in the portal and hepatic veins. It is of decisive importance in the differential diagnosis of oncological lesions of the liver.
- Ultrasound of organshepatobiliary system is the simplest, most accessible and informative research method. It allows you to identify stones in the gallbladder and bile ducts, optimal for detecting ascites.
Ultrasound of the organs 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 gases in the intestines so that the intestinal loops do not block the view of the organs under study. To do this, on the eve of the examination, you need to conduct a cleansing enema or take a laxative. 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. The examination should be carried out on an empty stomach, at least 8 hours must have passed since the last meal.
Diet before ultrasound
When conducting ultrasound of the organs of the hepatobiliary system, preparation must necessarily include, in addition to cleansing procedures, a diet that reduces gas formation. Here are its principles:
- Meals 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 foods that include yeast, fatty meat or fish, legumes, sugar, strong tea or coffee, carbonated or alcoholic drinks.
The 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.
