Hepatic duct anatomy. Diseases of the bile ducts

The biliary tract is complex system bile excretion, which includes intrahepatic and extrahepatic bile ducts and gallbladder.

Intrahepatic bile ducts- intercellular bile ducts, intralobular and interlobular bile ducts (Fig. 1.7, 1.8). Bile excretion begins with intercellular bile duct(sometimes called bile capillaries). The intercellular bile ducts do not have own wall, it is replaced by depressions on the cytoplasmic membranes of hepatocytes. The bile duct lumen is formed by the outer surface of the apical (capalicular) part of the cytoplasmic membrane of adjacent hepatocytes and dense contact complexes located at the points of contact of hepatocytes. Each hepatic cell participates in the formation of several bile ducts. Tight contacts between hepatocytes separate the lumen of the bile ducts from the circulatory system of the liver. Violation of the integrity of tight contacts is accompanied by regurgitation of canalicular bile into the sinusoids. Intralobular bile ducts (cholangioli) are formed from the intercellular bile ducts. Having passed through the border plate, cholangioli in the periportal zone merge into the periportal bile ducts. At the periphery of the hepatic lobules, they merge into the bile ducts proper, from which the interlobular ducts of the first order are subsequently formed, then the second order, and large intrahepatic ducts emerging from the liver are formed. When leaving the lobule, the ducts expand and form an ampulla, or Hering's intermediate duct. In this area, the bile ducts are in close contact with the blood and lymphatic vessels, in connection with which the so-called hepatogenous intrahepatic cholangiolitis can develop.

Intrahepatic ducts from the left, square and caudate lobes of the liver form the left hepatic duct. Intrahepatic ducts right lobe, merging with each other, form the right hepatic duct.

Extrahepatic biliary tract consist of a system of ducts and a reservoir for bile - the gallbladder (Fig. 1.9). The right and left hepatic ducts form a common hepatic duct into which the cystic duct flows. The length of the common hepatic duct is 2-6 cm, diameter is 3-7 mm.

The topography of the extrahepatic bile ducts is variable. There are many options for connecting the cystic duct to the common bile duct, as well as additional hepatic ducts and options for their flow into the gallbladder or common bile duct, which must be taken into account when diagnostic studies and during operations on the biliary tract (Fig. 1.10).

The confluence of the common hepatic and cystic ducts is considered upper bound common bile duct(its extramural part), which enters the duodenum (its intramural part) and ends with a large duodenal papilla on the mucous membrane. In the common bile duct, it is customary to distinguish between the supraduodenal part located above the duodenum; retroduodenal, passing behind the upper part of the intestine; retropancreatic, located behind the head of the pancreas; intrapancreatic, passing through the pancreas; intramural, where the duct enters obliquely through back wall top-down division duodenum(see fig. 1.9 and fig. 1.11). The length of the common bile duct is about 6-8 cm, the diameter is from 3-6 mm.

In the deep layers of the wall and the submucosa of the terminal section of the common bile duct, there are glands (see Fig. 1.9) that produce mucus, which can cause adenomas and polyps.

The structure of the end section of the common bile duct is very variable. In most cases (in 55-90%), the mouths of the common bile and pancreatic ducts merge into a common duct, forming an ampulla (V-shaped version), where bile and pancreatic juice are mixed (Fig. 1.12). In 4-30% of cases, there is a separate confluence of the ducts into the duodenum with the formation of independent papillae. In 6-8% of cases, they merge high (Fig. 1.13), which creates conditions for biliary-pancreatic and pancreatobiliary refluxes. In 33% of cases, the fusion of both ducts in the area of ​​the greater duodenal papilla occurs without the formation of a common ampulla.

The common bile duct, merging with the pancreatic duct, pierces the back wall of the duodenum and opens into its lumen at the end of the longitudinal fold of the mucous membrane, the so-called large duodenal papilla, called Vater's papilla. In about 20% of cases, 3-4 cm proximal to the Vater papilla on the duodenal mucosa, you can see the additional pancreatic duct - the small duodenal papilla (papilla duodeni minor, s. Santorini) (Fig. 1.14). It is smaller and not always functional. According to T. Kamisawa et al., The patency of the accessory pancreatic duct at 411 ERCP was 43%. The clinical significance of the accessory pancreatic duct is that with its preserved patency, pancreatitis develops less often (in patients with acute pancreatitis the duct functions only in 17% of cases). With a high pancreatobiliary connection, conditions are created for reflux of pancreatic juice into the biliary tree, which contributes to the development of the inflammatory process, malignant tumors and the so-called enzymatic cholecystitis. With a functioning additional pancreatic duct, the frequency of carcinogenesis is lower, since the reflux of pancreatic juice from the bile duct can be reduced due to its entry into the duodenum through the additional duct.

The formation of biliary pathology can be influenced by peripapillary diverticula, the frequency of which is about 10-12%, they are risk factors for the formation of stones of the gallbladder, bile ducts, create certain difficulties in performing ERCP, papillosphincterotomy, and are often complicated by bleeding during endoscopic manipulations in this area.

Gall bladder- a small hollow organ, the main functions of which are the accumulation and concentration of hepatic bile and its evacuation during digestion. The gallbladder is located in the depression of the pasceral surface of the liver between the square and its right lobes. The size and shape of the gallbladder is highly variable. Usually it has a pear-shaped, less often conical shape. The projection of the gallbladder onto the body surface is shown in Fig. 1.15.

The upper wall of the gallbladder is adjacent to the surface of the liver and is separated from it by loose connective tissue, the lower one faces the free abdominal cavity and is adjacent to the pyloric part of the stomach, duodenum and transverse colon (see Fig. 1.11), which causes the formation of various anastomosis with adjacent organs, for example, with a pressure ulcer of the wall of the gallbladder, developed from the pressure of a large immobile stone. Sometimes the gallbladder located intrahepatic or is completely outside the liver... In the latter case, the gallbladder is covered on all sides visceral peritoneum, has its own mesentery, is easily mobile. The mobile gallbladder is more prone to torsion, stones are easily formed in it.

The length of the gallbladder is 5-10 cm or more, and the width is 2-4 cm. In the gallbladder, there are 3 sections: the bottom, body and neck (see Fig. 1.9). The widest part of it is the bottom, it is this part of the gallbladder that can be palpated when the common bile duct is obstructed (Courvoisier's symptom). The body of the gallbladder passes into the neck - its narrowest part. In humans, the neck of the gallbladder ends in a blind bag (Hartman's pocket). The neck contains a spiral Keister fold, which can complicate the evacuation of biliary sludge and small gallstones, as well as their fragments after lithotripsy.

Usually the cystic duct departs from the upper-lateral surface of the neck and flows into the common bile duct 2-6 cm further than the confluence of the right and left hepatic ducts. Exists different options its confluence into the common bile duct (Fig. 1.16). In 20% of cases, the cystic duct does not immediately connect to the common bile duct, but is located parallel to it in the common connective tissue membrane. V individual cases the cystic duct wraps around the common bile duct in front or behind. One of the features of their connection is the high or low confluence of the cystic duct into the common bile duct. The options for connecting the gallbladder and bile ducts on cholangiograms are about 10%, which must be taken into account during cholecystectomy, since incomplete removal of the gallbladder leads to the formation of the so-called long stump syndrome.

The thickness of the gallbladder wall is 2-3 mm, the volume is 30-70 ml, in the presence of an obstacle to the outflow of bile through the common bile duct, the volume in the absence adhesive process in the bladder it can reach 100 and even 200 ml.

Biliary tract equipped with a complex sphincter apparatus, working in a clearly coordinated mode. There are 3 groups of sphincters. At the confluence of the cystic and common bile ducts, there are bundles of longitudinal and circular muscles that form the Mirizzi sphincter. When it contracts, the flow of bile through the duct stops, while the sphincter prevents the retrograde flow of bile during contraction of the gallbladder. However, not all researchers recognize the presence of this sphincter. In the area of ​​transition of the neck of the gallbladder and the cystic duct there is a spiral sphincter of Lutkens. In the terminal section, the common bile duct is surrounded by three layers of muscles that form the Oddu sphincter, named after Ruggero Oddi (1864-1937). The sphincter of Oddi is a heterogeneous formation. It distinguishes between accumulations of muscle fibers surrounding the extra- and intramural part of the duct. The fibers of the intramural region partially pass to the ampulla, Another muscle pulp with the terminal section of the common bile duct surrounds the large duodenal papilla (papilla sphincter). They approach him, bending around him, the muscles of the duodenum. An independent sphincter is a muscle mass that surrounds the end of the pancreatic duct.

Thus, if the common bile and pancreatic ducts merge together, then the sphincter of Oddi consists of three muscle formations: the sphincter of the common bile duct, which regulates the flow of bile into the ampulla of the duct; the sphincter of the papilla, which regulates the flow of bile and pancreatic juice into the duodenum, protecting the ducts from reflux from the intestine, and, finally, the sphincter of the pancreatic duct, which controls the release of pancreatic juice (Fig. 1.17).

In the mucous membrane of the duodenum, this anatomical formation is defined as a hemispherical, conical or flattened eminence (Fig. 1.18, A, B) and is designated as a large duodenal papilla, a large duodenal papilla, papilla vater: lat. papilla duodeni major. Named after the German anatomist Abraham Vater (1684-1751). The size of the Vater papilla at the base is up to 1 cm, the height is from 2 mm to 1.5 cm, it is located at the end of the longitudinal fold of the mucous membrane in the middle of the descending part of the duodenum approximately 12-14 cm distal pylorus.

With dysfunction of the sphincter apparatus, a violation of the outflow of bile occurs, and in the presence of other factors (vomiting, duodenal dyskinesia), pancreatic juice and intestinal contents can enter the common bile duct with the subsequent development of inflammation in the ductal system.

The length of the intramural part of the common bile duct is about 15 mm. In this regard, to reduce the number of complications after endoscopic papillotomy, it is necessary to make a 13-15 mm incision in the upper sector of the large duodenal papilla.

Histological structure. The wall of the gallbladder consists of mucous, muscular and connective tissue (fibrous-muscular) membranes, the lower wall is covered with a serous membrane (Fig. 1.19), and the upper one does not have it, it is adjacent to the liver (Fig. 1.20).

The main structural and functional element the wall of the gallbladder is the mucous membrane. Macroscopic examination of the opened bladder inner surface the mucous membrane has a fine-meshed appearance. Average cell diameter irregular shape 4-6 mm. Their boundaries are formed by delicate low folds 0.5-1 mm high, which flatten and disappear when the bubble is filled, i.e. are not a stationary anatomical formation (Fig. 1.21). The mucous membrane forms numerous folds, due to which the bladder can significantly increase its volume. There is no submucosa and proper muscle plate in the mucous membrane.

The thin fibromuscular membrane is represented by irregularly located smooth muscle bundles, mixed with a certain amount of collagen and elastic fibers (see Fig. 1.19, Fig. 1.20). Bunches of smooth muscle cells of the bottom and body of the bladder are located in two thin layers at an angle to each other, and circular in the neck area. On transverse sections of the gallbladder wall, it can be seen that 30-50% of the area occupied by smooth muscle fibers is represented by loose connective tissue. Such a structure is functionally justified, since when the bladder is filled with bile, the connective tissue layers with large quantity elastic fibers, which protects muscle fibers from overstretching and damage.

Crypts or sinuses of Rokitansky-Ashoff, which are branched invaginates of the mucous membrane, penetrating through muscle layer the walls of the gallbladder (Fig. 1.22). This feature anatomical structure mucous membrane contributes to the development of acute cholecystitis or gangrene of the wall of the gallbladder, stagnation of bile or the formation of microliths or calculi in them (Fig. 1.23). Despite the fact that the first description of these structural elements of the gallbladder wall was made by K. Rokitansky in 1842 and supplemented in 1905 by L. Aschoff, the physiological significance of these formations was estimated only in Lately... In particular, they are one of the pathognomonic acoustic symptoms in gallbladder adenomyomatosis. In the wall of the gallbladder there are Lushka's moves- blind pockets, often branched, sometimes reaching the serous membrane. They can accumulate microbes with the development of inflammation. With the narrowing of the mouth of Lushka's passages, intramural abscesses may form. When removing the gallbladder, these passages in some cases can be the cause of bile leakage in the early postoperative period.

The surface of the mucous membrane of the gallbladder is covered with high prismatic epithelium. On the apical surface of epithelial cells, there are numerous microvilli that form the suction border. In the neck area, there are alveolar-tubular glands that produce mucus. V epithelial cells enzymes found: β-glucuronidase and esterase. Using histochemical study, it was found that the mucous membrane of the gallbladder produces a carbohydrate-containing protein, and the cytoplasm of epithelial cells contains mucoproteins.

Bile duct wall consists of mucous membrane, muscular (fibromuscular) and serous membranes. Their severity and thickness increase in the distal direction. The mucous membrane of the extrahepatic bile ducts is covered with a single layer of high prismatic epithelium. It contains many mucous glands. In this regard, the duct epithelium can perform both secretion and resorption and synthesizes immunoglobulins. The surface of the bile ducts is smooth over a greater extent, in the distal part of the common duct it forms pocket-like folds, in some cases making it difficult to probe the duct from the side of the duodenum.

The presence of muscle and elastic fibers in the wall of the ducts ensures their significant expansion in biliary hypertension, compensates for bile outflow even with a mechanical obstacle, for example, with choledocholithiasis or the presence of putty bile in it, without clinical symptoms obstructive jaundice.

A feature of the smooth muscles of the sphincter of Oddi is that its myocytes, in comparison with the muscle cells of the gallbladder, contain more γ-actin than α-actin. Moreover, the actin of the muscles of the sphincter of Oddi has more similarities with the actin of the longitudinal muscular layer of the intestine than, for example, with the actin of the muscles of the lower esophageal sphincter.

The outer membrane of the ducts is formed by loose connective tissue, in which the vessels and nerves are located.

Blood is supplied to the gallbladder by the cystic artery... It is a large tortuous branch of the hepatic artery that has various anatomical location... In 85-90% of cases, it departs from the right branch of its own hepatic artery. Less commonly, the cystic artery originates from the common hepatic artery. The cystic artery usually crosses the hepatic duct from behind. The characteristic location of the cystic artery, cystic and hepatic ducts forms the so-called kahlo triangle.

As a rule, the cystic artery has a single trunk, less often it splits into two arteries. Considering the fact that this artery is terminal and with age can undergo atherosclerotic changes, the risk of necrosis and perforation in the elderly is significantly increased in the presence of an inflammatory process in the wall of the gallbladder. Smaller blood vessels penetrate into the wall of the gallbladder from the liver through its bed.

Gallbladder veins are formed from the intramural venous plexuses, forming the cystic vein, which flows into portal vein .

Lymphatic system... In the gallbladder there are three networks of lymphatic capillaries: in the mucous membrane under the epithelium, in the muscle and serous membranes... Emerging from them lymphatic vessels form a sub-serous lymphatic plexus, which anastomoses with the lymphatic vessels of the liver. The outflow of lymph is carried out in The lymph nodes located around the neck of the gallbladder, and then into the lymph nodes located at the gate of the liver and along the common bile duct. Subsequently, they are connected to the lymphatic vessels that drain the lymph from the head of the pancreas. Enlarged lymph nodes with inflammation ( pericholedocheal lymphadenitis) can cause obstructive jaundice.

Innervation of the gallbladder carried out from the hepatic nerve plexus, formed by the branches of the celiac plexus, the anterior vagus trunk, phrenic nerves and gastric plexus. Sensitive innervation is carried out by nerve fibers of the V-XII thoracic and I-II lumbar segments spinal cord... In the wall of the gallbladder, the first three plexuses are distinguished: submucosal, intermuscular and sub-serous. In chronic inflammatory processes in the gallbladder, degeneration of the nervous apparatus occurs, which is the basis of chronic pain syndrome and dysfunction of the gallbladder. The innervation of the biliary tract, pancreas and duodenum has a common origin, which determines their close functional relationship and explains the similarity clinical symptoms... In the gallbladder, cystic and common bile ducts, there are nerve plexuses and ganglia, similar to those in the duodenum.

Blood supply to the biliary tract carried out by numerous small arteries originating from its own hepatic artery and its branches. The outflow of blood from the wall of the ducts goes into the portal vein.

Lymphatic drainage occurs through the lymphatic vessels located along the ducts. The close connection between the lymphatic pathways of the bile ducts, gallbladder, liver and pancreas plays a role in metastasis in malignant lesions of these organs.

Innervation carried out by the branches of the hepatic nerve plexus and interorgan communication according to the type of local reflex arcs between the extrahepatic biliary tract and other digestive organs.

Bile ducts- an accumulation of tubular channels through which bile leaves the liver and gallbladder. The pressure generated in the liver, contraction of the sphincters, the activity of the walls of the ducts contribute to the movement of bile. Every day, about 1 liter of yellow-green fluid enters the intestines through the bile network.

Biliary tract and their structure

The anatomy of the bile-excreting system is represented by two types of ducts - intrahepatic and hepatic:

• Intrahepatic. From the name it becomes clear that the ducts are located inside the tissue of the organ, arranged in neat rows of small ducts. It is in them that the finished bile fluid comes from the liver cells. Liver cells secrete bile, which enters the space of the small bile ducts, and through the interlobular tubules enters the large canals.
• Hepatic. Uniting with each other, the tubules form the right and left ducts that drain bile from the right and left side of the liver. At the transverse "crossbar" of the liver, the ducts are combined and form a common duct.

The extrahepatic biliary system is built on the following ducts:

• Vesicular - is the link between the liver and the gallbladder.
• Common bile duct. It originates from the place where the hepatic and the cystic one joins, flows into the duodenum. Some of the secretion goes directly to the common bile duct, without entering the gallbladder.

The common bile duct has a complex valve system consisting of muscle tissue... The Lutkins sphincter provides the passage of secretion by the cystic canal and the bladder neck, the Mirizzi sphincter unites the cystic and common bile ducts. The Oddi valve is located in the lower reaches of the common duct. At rest, the valve is closed, which allows fluid to collect and concentrate in the bile. At this time, the color of the bile changes to dark olive, the amount of enzymes increases several times. In the process of digesting food, active substance, due to which the valve opens, the bile is compressed and fluid is released into the digestive system.

Diseases of the bile ducts

Blockage of ducts with stones.

The correct composition of bile healthy ways its output is necessary for correct work organism. Experts have diagnosed many diseases of the biliary tract, consider the frequently encountered ones:

Blocked ducts

On the path of movement of bile, a mechanical obstacle can form. As a result, the channels are blocked, the free passage of bile is impaired. Blockage of the ducts is a dangerous exacerbation of the underlying disease, which is the culprit for the development of obstructive jaundice. Disorder of patency is divided into complete and partial. How clogged the ducts depends on clinical picture, the brightness of the manifestation of signs. One of common reasons the occurrence of obstacles for the passage of secretions is cholelithiasis.

Cholelithiasis is a gallstone disease. It is characterized by the formation of calculi (stones) not only in the ducts, but also in the bladder. The culprit for the formation of stones is stagnation in the produced fluid, a change in metabolism. The connection of calculi is different. It contains yellow blood pigment (bilirubin), acids, natural fatty alcohol (cholesterol).

There are cases when stones have been in the human body for years, but he does not suspect anything. Worse when a stone blocks the duct, as this situation gives rise to trouble (inflammation, colic). With the onset of the inflammatory process, pain arises, which is concentrated in the area of ​​the right hypochondrium, and can be given to the back. An increase in temperature, vomiting often accompany the inflammatory process. Help, provided at the wrong time, leads to the development of liver failure, which can result in death.

The onset and development of complications occurs in several stages. Inflammatory process ducts serves as a trigger for the onset of complications. It promotes thickening of the walls, as a result, a decrease in the lumen. There is not enough space for the stone passing through the duct during this period, a blockage is formed that closes the bile path. The fluid accumulates, stretching the walls of the organ, and can immediately go into the bladder, stretching the organ, causing an exacerbation.

Narrowing of the ducts

Internal narrowing can form anywhere in the common, lobar, hepatic canals. Its appearance indicates the cause of the problem. V surgical treatment narrowing the diameter of the channels is one of the most pressing and difficult issues. According to the results of the research, three forms of stricture are distinguished:

When strictures appear, the places above the narrowed parts of the vessels are expanded. In the place of difficult circulation, bile stagnates, thickens, creating a favorable climate for the occurrence of stones. Signs of a problem will be:

• pain in the right side of the peritoneum;
• yellowness of the skin;
• nausea;
• vomit;
• strong weight loss;
• flatulence;
• the color of urine, feces changes.

Stopping or reducing the flow of bile circulation leads to the ingress of bilirubin, acids into the bloodstream, which causes damage to the body:

• the absorption of nutrients is impaired;
• blood clotting worsens;
• the liver is disrupted;
• abscesses appear;
• sepsis.

Coming out of the liver right and left hepatic ducts at the gate of the liver they join, forming a common hepatic duct, ductus hepaticus communis. Between the leaves of the hepato-duodenal ligament, the duct descends 2-3 cm down to the junction with the cystic duct. Behind it are the right branch of its own hepatic artery (sometimes it passes in front of the duct) and the right branch of the portal vein.

Cystic duct, ductus cysticus, with a diameter of 3-4 mm and a length of 2.5 to 5 cm, leaving the neck of the gallbladder, heading to the left, flows into the common hepatic duct. The angle of confluence and distance from the gallbladder neck can be very different. On the mucous membrane of the duct, a spiral fold, plica spiralis, is isolated, which plays a role in regulating the outflow of bile from the gallbladder.

Common bile duct, ductus choledochus, is formed as a result of the connection of the common hepatic and cystic ducts. It is located first in the free right edge of the hepato-duodenal ligament. The portal vein is located to the left and somewhat posterior to it. The common bile duct drains bile into the duodenum. Its length is on average 6-8 cm.Along the common bile duct, 4 parts are distinguished:

1) supraduodenal part common bile duct goes to the duodenum in the right edge of the lig. hepatoduodenale and has a length of 1-3 cm;
2) retroduodenal part common bile duct about 2 cm long, located behind the upper horizontal part of the duodenum, about 3-4 cm to the right of the pylorus. Above and to the left of it passes the portal vein, below and to the right - a. gastroduodenalis;
3) pancreatic part common bile duct up to 3 cm in length passes in the thickness of the head of the pancreas or behind it. In this case, the duct is adjacent to the right edge of the inferior vena cava. The portal vein lies deeper and crosses the pancreatic part of the common bile duct obliquely on the left;
4) interstitial, terminal, part common bile duct has a length of up to 1.5 cm. The duct pierces the posterior medial wall of the middle third of the descending part of the duodenum in an oblique direction and opens at the apex of the large (Vater) duodenal papilla, papilla duodeni major. The papilla is located in the region of the longitudinal fold of the intestinal mucosa. Most often, the final part of the ductus choledochus merges with the pancreatic duct, forming when entering the intestine hepato-pancreas ampoule, ampulla hepatopancreatica.

In the thickness of the wall of the large duodenal papilla, the ampulla is surrounded by smooth circular muscle fibers that form sphincter of the hepato-pancreatic ampulla, m. sphincter ampullae hepatopancreaticae.

Instructional video of the anatomy of the gallbladder, bile ducts and Kahlo triangle

The right and left hepatic ducts exit from the liver, merging at the gate into the common hepatic duct. As a result of its fusion with the cystic duct, a common bile duct is formed.

The common bile duct runs between the leaves of the lesser omentum anterior to the portal vein and to the right of the hepatic artery. Located posterior to the first section of the duodenum in the groove on the posterior surface of the head of the pancreas, it enters the second section of the duodenum. The duct obliquely crosses the posterior medial wall of the intestine and usually connects with the main duct of the pancreas, forming the hepato-pancreas ampulla (ampulla of Vater). The ampoule forms a protrusion of the mucous membrane directed into the intestinal lumen - the large papilla of the duodenum (vater papilla). In about 12-15% of those examined, the common bile duct and the pancreatic duct open separately into the duodenal lumen.

The size of the common bile duct, when determined by different methods, turns out to be unequal. The diameter of the duct, measured during operations, ranges from 0.5 to 1.5 cm. In endoscopic cholangiography, the diameter of the duct is usually less than 11 mm, and the diameter of more than 18 mm is considered pathological. At ultrasound examination(Ultrasound) normally it is even less and is 2-7 mm; with a larger diameter, the common bile duct is considered dilated.

The part of the common bile duct that runs in the wall of the duodenum is surrounded by a shaft of longitudinal and circular muscle fibers called the sphincter of Oddi.

The gallbladder is a 9 cm long pear-shaped sac that can hold about 50 ml of liquid. It is always located above the transverse colon, adjacent to the duodenal bulb, projecting onto the shadow of the right kidney, but located significantly in front of it.

Any decrease in the concentration function of the gallbladder is accompanied by a decrease in its elasticity. The widest part is the bottom, which is located in front; it is this that can be palpated when examining the abdomen. The body of the gallbladder passes into a narrow neck, which continues into the cystic duct. The spiral folds of the mucous membrane of the cystic duct and the neck of the gallbladder are called the Heister flap. Saccular expansion of the gallbladder neck, in which often forms gallstones, is called Hartman's pocket.

The wall of the gallbladder consists of a network of muscle and elastic fibers with indistinct layers. The muscle fibers of the neck and bottom of the gallbladder are especially well developed. The mucous membrane forms numerous delicate folds; there are no glands in it, but there are depressions that penetrate into the muscle layer, called Lyushka's crypts. The mucous membrane does not have a submucous layer and its own muscle fibers.

The sinuses of Rokitansky-Ashoff are branched invaginations of the mucous membrane, penetrating through the entire thickness of the muscular layer of the gallbladder. They play an important role in the development of acute cholecystitis and gangrene of the bladder wall.

Blood supply. The gallbladder is supplied with blood from the cystic artery. It is a large, convoluted branch of the hepatic artery that can have various anatomical locations. Smaller blood vessels enter from the liver through the fossa of the gallbladder. Blood from the gallbladder flows through the cystic vein into the portal vein system.

The blood supply to the supraduodenal bile duct is carried out mainly by the accompanying two arteries. Blood in them comes from the gastroduodenal (bottom) and right hepatic (top) arteries, although their connection with other arteries is possible. Strictures of the bile ducts after vascular injury can be explained by the peculiarities of the blood supply to the bile ducts.

The lymphatic system. In the mucous membrane of the gallbladder and under the peritoneum, there are numerous lymphatic vessels. They pass through the node at the neck of the gallbladder to the nodes located along the common bile duct, where they connect to the lymphatic vessels that drain lymph from the head of the pancreas.

Innervation. The gallbladder and bile ducts are abundantly innervated by parasympathetic and sympathetic fibers.

Development of the liver and bile ducts

The liver is laid in the form of a hollow protrusion of the endoderm of the anterior (duodenal) intestine at the 3rd week intrauterine development... The protrusion is divided into two parts - hepatic and biliary. The hepatic part consists of bipotent progenitor cells, which then differentiate into hepatocytes and ductal cells, which form the early primitive bile ducts - ductal plates. When cells differentiate, the type of cytokeratin changes in them. When the c-jun gene, which is part of the API gene activation complex, was removed in the experiment, liver development stopped. Normally, fast-growing cells of the hepatic part of the protrusion of the endoderm perforate the adjacent mesodermal tissue (transverse septum) and meet capillary plexuses growing in its direction, emanating from the yolk and umbilical veins. From these plexuses, sinusoids are subsequently formed. The biliary part of the protrusion of the endoderm, connecting with the proliferating cells of the hepatic part and with the anterior intestine, forms the gallbladder and extrahepatic bile ducts. Bile begins to flow around the 12th week. Hematopoietic cells, Kupffer cells and connective tissue cells are formed from the mesodermal transverse septum. In the fetus, the liver mainly performs the function of hematopoiesis, which dies out in the last 2 months of intrauterine life, and by the time of delivery, only a small number of hematopoietic cells remain in the liver.

There are three extrahepatic bile ducts (see fig.): common hepatic duct, ductus hepaticus communis, cystic duct, ductus cysticus, and common bile duct, ductus choledochus (biliaris).

The common bile duct connects with the pancreatic duct and flows into the common cavity - hepato-pancreatic ampulla, ampulla hepatopancreatica, which opens into the lumen of the descending part of the duodenum at the top of it large papilla, papilla duodeni major, at a distance of 15 cm from the pylorus. The ampoule size can be up to 5x12 mm.

The type of confluence of the ducts can vary: they can open into the intestine with separate mouths, or one of them can flow into the other.

In the area of ​​the large papilla of the duodenum, the orifices of the ducts are surrounded by muscle - this is sphincter of the hepato-pancreatic ampoule (sphincter of the ampoule), m. sphincter ampullae hepatopancreaticae (m. sphincter ampulae)... In addition to the circular and longitudinal layers, there are separate muscle bundles that form an oblique layer, which combines the sphincter of the ampulla with the sphincter of the common bile duct and with the sphincter of the pancreatic duct (see Fig.).

Bile duct topography

The extrahepatic ducts are embedded in the hepato-duodenal ligament together with the common hepatic artery, its branches and the portal vein. At the right edge of the ligament is the common bile duct, to the left of it is the common hepatic artery, and deeper than these formations and between them is the portal vein; in addition, lymphatic vessels, nodes and nerves lie between the sheets of the ligament.

The division of the own hepatic artery into the right and left hepatic branches occurs in the middle of the length of the ligament, and the right hepatic branch, heading upward, passes under the common hepatic duct; at the point of their intersection, the gallbladder artery departs from the right hepatic branch, a. cystica, which goes to the right and up in the area of ​​the angle (gap) formed by the fusion of the cystic duct with the common hepatic duct. Further, the gallbladder artery passes along the wall of the gallbladder.

Innervation: liver, gallbladder and bile ducts - plexus hepaticus (truncus sympathicus, nn.vagi).

Blood supply: liver - a. hepatica propria, and its branch a. cystica approaches the gallbladder and its ducts. In addition to the artery, v enters the gate of the liver. portae, which collects blood from unpaired organs in the abdominal cavity; passing through the system of intraorgan veins, leaves the liver through vv. hepaticae flowing into v. cava inferior (see vol. 3 "Venous system"). From the gallbladder and its ducts deoxygenated blood flows into the portal vein. Lymph is removed from the liver and gallbladder in nodi lymphatici hepatici, phrenici superior et inferior, lumbales dextra, celiaci, gastrici, pylorici, pancreatoduodenales, anulus lymphaticus cardiae, parasternales.