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Topography of the duodenum. Human duodenum

1. Duodenum represents the initial section of the small intestine between the stomach and jejunum. Distinguish 4 departments:
upper
descending
horizontal
ascending.
Top part– between the pylorus of the stomach and the superior flexure of the intestine, located at the free edge of the lig. Hepatoduodenale, 3/4 covered by peritoneum. Descending part starts from the upper bend in the form of an arc, falls down, forming a lower bend and passes into the horizontal (lower) part. Its upper section is located in the upper floor of the abdominal cavity. The middle portion lies behind the root of the mesentery of the transverse colon. The lower section is to the right of the root of the mesentery of the small intestine. The peritoneum covers the anterior outer part of the intestine above the mesentery of the transverse colon. The posterior internal surface is adjacent to the head of the pancreas . Horizontal(bottom) and ascending the parts run horizontally in the form of a gentle arc from the lower bend to the duodenum-jejunal bend. The lower part is covered with peritoneum in front, except for the ascending portion located behind the root of the mesentery of the small intestine.
Duodenum projected on the anterior abdominal wall between two horizontal lines, the upper one - through the anterior ends of the VIII ribs, the lower one - through the navel; and two vertical ones, the left one is 4 cm to the left of the midline, the right one is 6–8 cm to the right of it. Bulb is projected 4–6 cm above the navel in the middle of the width of the right rectus abdominis muscle. The upper level corresponds to the upper edge of the 1st lumbar vertebra, the lower – to the 4th lumbar vertebra.
2. Duodenal ligaments. The hepatoduodenal ligament - between the porta hepatis and the upper wall of the bulb, being the extreme right part of the lesser omentum, limits the omental foramen in front. Duodenal ligament- a fold stretched between the outer posterior edge of the descending part and the area of the right kidney. Limits the stuffing box opening from below. Supportive Treitz's ligament formed by a fold of peritoneum covering the muscle that suspends the duodenum. Large duodenal(of Vater) papilla - the place where the common bile duct and the pancreatic duct enter the duodenum, located on the border of the lower and middle third of the descending part of the intestine along the posteromedial wall. At the top of the papilla there is an orifice with a diameter of 2–4.5 mm, through which bile and pancreatic juice flow. Sometimes two orifices open on the papilla - the orifice of the main pancreatic duct and higher - the orifice of the common bile duct. Even higher, on small duodenal The accessory duct of the pancreas opens into the papilla. Blood supply carried out from aa.gastroduodenalis and mesenterica superior. The anterior and posterior (superior and inferior) pancreaticoduodenal arteries depart from them. Moreover, the anterior ones form the anterior arterial arch, and the posterior ones form the posterior one. The ampulla (bulb) is supplied with blood due to aa.gastroduodenalis, a.gastroepiploica dextra, a. gastrica dextra and hepatica propria. The veins follow the course of the arteries of the same name, flowing into the portal vein system.

LECTURE 27. OPERATIVE STOMACH SURGERY

1. Gastrostomy according to Witzel. Indications– inoperable cancer of the esophagus and cardial part of the stomach, wounds, burns, narrowing of the esophagus. Access– transrectal left-sided laparotomy. The stomach is brought out into the surgical wound. A rubber tube is placed on the front wall in the middle between the lesser and greater curvatures so that its end is located in the area of the pylorus. Placed over the tube seromuscular sutures, and in the area of the pylorus - purse string. Inside the purse-string suture, the wall of the stomach is opened and the free end of the tube is inserted there, the purse-string suture is tightened and two seromuscular sutures are placed above it. The other end of the tube is removed through a separate skin incision along the outer edge of the left rectus muscle. The stomach wall is fixed along the formed canal to the parietal peritoneum with interrupted sutures. The Topprorov operation begins as well. The stomach wall is brought into the wound in the form of a cone and two holders are placed at a distance of 2 cm. Below them, three purse-string sutures are placed concentrically at a distance of 1.5–2 cm from each other. The wall between the holders is cut and a rubber tube is inserted. The purse string sutures are tightened one by one, and the tube ends up in the artificial canal. The stomach is fixed to the parietal peritoneum and to the aponeurotic sheath of the rectus abdominis muscle. The third row of sutures is used to suture the stomach wall to the skin to form a permanent labiform fistula.
2. Gastroenteroanastomosis. Indications– inoperable cancer of the pyloric part of the stomach, cicatricial narrowing of the pylorus in a weakened patient. Access– upper median laparotomy. Anterior anterior colonic gastrojejunostomy(according to Welfler). The greater omentum with the transverse colon is brought out into the wound.
The first loop of the jejunum is found and a section 50 cm long is measured. The intestinal loop is brought to the anterior wall of the stomach in front of the greater omentum and the transverse colon. The adductor loop (small loop) is fixed with a silk suture at the lesser curvature, closer to the cardiac part, the abductor loop (greater loop) - at the greater curvature, closer to the pyloric part of the stomach, after which a posterior row of serous-muscular sutures is applied. First, the stomach is opened, and then the small intestine, moving away from the seromuscular suture. A continuous catgut suture is applied through all layers to the posterior edges (lips) of the anastomosis, and then to the anterior edges - Schmieden suture, after which a second row of interrupted seromuscular sutures is applied to the anterior edges (lips) of the anastomosis. Posterior retrocolic gastrojejunostomy according to Hacker-Petersen. For anastomosis, a 7–10 cm long loop of jejunum is taken from the flexura duodenojejunalis. The transverse colon is dissected in the vertical direction, below the arch of Riolan, in the avascular zone. With the left hand, located on the front wall of the stomach, the back wall of the stomach is protruded. The intestinal loop is fixed to the stomach with two silk sutures in a direction vertical to the axis of the stomach; the adductor loop is closer to the lesser curvature, the abductor loop is closer to the greater curvature. The gastrointestinal anastomosis is applied according to the method described above, side to side.
3. With a perforated ulcer The gastric perforation is sutured. Access – upper median laparotomy. A perforation is detected, which is often located in the pyloric region on the anterior wall of the stomach. The hole is sutured with interrupted seromuscular sutures in a direction transverse to the axis of the stomach, followed by the application of a second row of seromuscular sutures in the same direction.

LECTURE 28. GASTRIC RESECTION

1. Indications:
complicated ulcers of the stomach and duodenum (bleeding, penetrating, callous, pyloric stenosis)
benign tumors (polyps, adenomas)
stomach cancer
2. Gastric resection according to Billroth I. An upper midline laparotomy is performed.
Mobilization of the stomach along the greater curvature. The stomach and transverse colon are removed into the wound. The gastrocolic ligament is opened at the level of the middle third of the stomach. Between the clamps, the ligament and arteries are crossed to the intended level along the left half of the greater curvature. The branches of a. are also tied and cut. gastroepiploica dextra to the right from the beginning of mobilization to the level of the pylorus. At the level of the pylorus, the main trunk of a. is separately bandaged. gastroepiploica dextra. Branches coming from the central part of a. gastroepiploica dextra to the pylorus and duodenum is cut between clamps and bandaged. 2-3 branches of the artery going to the posterior surface of the duodenum are ligated and crossed. The lesser omentum is first dissected in the avascular zone, and then clamps are applied, squeezing the left gastric artery between them, which is crossed and ligated. The right gastric artery is ligated between the clamps. Resection begins from the side of the greater curvature; a clamp is applied perpendicular to the axis of the stomach to the width of the anastomosis. The second clamp grasps the rest of the diameter from the side of lesser curvature. Distal to these clamps, a Payra crushing press is applied to the removed part of the stomach, along which the stomach is cut off. A marginal wrapping suture is applied to the part of the gastric stump being sutured. The upper edge of the lesser curvature of the stomach is immersed with a semi-purse string suture. Separate seromuscular sutures are applied to the remaining part. An anastomosis is created between the gastric stump and the duodenum (the width of the anastomosis on the gastric stump is greater than that of the duodenum).
2. Gastric resection using the Billroth II method modified by Hoffmeister-Finsterer. An upper midline laparotomy is performed. Mobilization of the stomach and duodenum. The duodenal stump is sutured with a continuous wrapping suture. The stump is immersed either with a Z-shaped and circular purse-string silk sutures, or with two semi-purse-string sutures with additional serous-serous sutures. The stomach is removed and its stump is processed. A gastrointestinal anastomosis is applied so that the adducting end is at the lesser curvature (not reaching it by 2–3 cm), and the efferent end is at the greater curvature. The afferent intestine is sutured above the level of the anastomosis to the lesser curvature of the stomach. Gastroenteroanastomosis is applied using a double-row suture (continuous catgut suture on the posterior edges of the anastomosis through all layers with a transition to the anterior edges like a screw-in Schmieden suture and interrupted silk seromuscular sutures on the anterior semicircle of the anastomosis).

The duodenum (duodenum), 25-30 cm long, begins with a bulbous extension from the pyloric sphincter and ends with a duodenal-jejunal bend (flexura duodenojejunalis), connecting it to the jejunum (Fig. 240). Compared to other parts of the small intestine, it has a number of structural features and, naturally, functions and topography. It should be noted that pathological processes often occur in the duodenum, as in the stomach, sometimes requiring not only therapeutic treatment, but also surgical intervention. This circumstance imposes certain requirements on knowledge of anatomy.

The duodenum is devoid of a mesentery and its posterior surface is attached to the posterior abdominal wall. The most typical (60% of cases) is the irregular horseshoe-shaped intestine (Fig. 240), in which the upper (pars superior), descending (pars descendens), horizontal (pars horizontalis inferior) and ascending (pars ascendens) parts are distinguished.

The upper part is a segment of the intestine from the pyloric sphincter to the superior flexure of the duodenum, 3.5-5 cm long, 3.5-4 cm in diameter. The upper part is adjacent to m. psoas major and to the body of the first lumbar vertebra on the right. There are no folds in the mucous membrane of the upper part. The muscle layer is thin. The peritoneum covers the upper part mesoperitoneally, which ensures its greater mobility compared to other parts. The upper part of the intestine is in contact with the quadrate lobe of the liver from above, in front - with the gallbladder, in the back - with the portal vein, common bile duct and gastroduodenal artery, and below - with the head of the pancreas (Fig. 241).

240. Duodenum (partially opened) and pancreas with prepared ducts (front view).
1 - corpus pancreatici; 2 - ductus pancreaticus; 3 - flexura duodenojejunalis; 4 - pars ascendens duodeni; 5 - pars horizontalis (inferior) duodeni; 6 - plicae circulares; 7 - papilla duodeni major; 8 - papilla duodeni minor; 9 - pars descendens duodeni; 10 - ductus pancreaticus accessorius; 11 - pars superior duodeni; 12 - pars duodeni superior.

241. Duodenum, pancreas, gallbladder and bile ducts (posterior view).
1 - ductus hepaticus; 2 - ductus cysticus; 3 - vesica fellea; 4 - ductus choledochus; 5 - pars descendens duodeni; 6 - ductus pancreaticus; 7 - peritoneum; 8 - caput pancreatis; 9 - pars horizontalis duodeni; 10 - processus uncinatus; 11 - pars ascendens duodeni; 12 - a. mesenterica superior; 13 - v. mesenterica superior; 14 - flexura duodenojejunalis; 15 - cauda pancreatis; 16 - margo superior; 17 - corpus pancreatis; 18 - vena lienalis.

The descending part of the duodenum has a length of 9-12 cm, a diameter of 4-5 cm. It starts from the upper bend (flexura duodeni superior) and at the level of the first lumbar vertebra to the right of the spinal column and ends with the lower bend at the level of the third lumbar vertebra.

In the mucous membrane of the descending part, circular folds and conical villi are well defined. In the middle zone of the descending intestine, the common bile duct and pancreatic duct open on the posteromedial wall. The ducts pierce the wall obliquely and, passing through the submucosa, lift the mucous membrane, forming a longitudinal fold (plica longitudinalis duodeni). At the lower end of the fold there is a large papilla (papilla major) with an opening for the ducts. 2-3 cm above it is the small papilla (papilla minor), where the mouth of the small pancreatic duct opens. As the pancreatic ducts and the common bile duct pass through the muscle wall, it transforms and forms circular muscle fibers around the mouths of the ducts, forming a sphincter (m. sphincter ampullae hepatopancreaticae) (Fig. 242). The sphincter is anatomically connected to the muscular layer of the intestine, but is functionally independent, being under the control of the autonomic nervous system, as well as chemical and humoral stimuli. The sphincter regulates the flow of pancreatic juice and liver bile into the intestine.

242. The structure of the sphincter of the common bile duct and the pancreatic duct (according to T. S. Koroleva).

1 - ductus choledochus;
2 - ductus pancreaticus;
3 - m. sphincter ampullae hepatopancreaticae;
4 - layer of longitudinal muscles of the duodenum;
5 - circular layer of the duodenum.

The descending part is inactive; it is located behind the peritoneum and is fused with the posterior abdominal wall, the head of the pancreas and its duct, as well as with the common bile duct. This part is crossed by the mesentery of the transverse colon. The descending part of the duodenum comes into contact in front with the right lobe of the liver, in the back with the right kidney, the inferior vena cava, laterally with the ascending part of the colon, and medially with the head of the pancreas.

The horizontal part starts from the lower bend of the duodenum, has a length of 6-8 cm, crosses the body of the third lumbar vertebra in front. The mucous membrane has well-defined circular folds, the serous membrane covers the horizontal part only in front. The horizontal part of the upper wall is in contact with the head of the pancreas. The posterior wall of the intestine is adjacent to the inferior vena cava and right renal veins.

The ascending part continues from the horizontal part of the duodenum, its length is 4-7 cm. It is located to the left of the spine and at the level of the II lumbar vertebra it passes into the jejunum, forming a duodenojejunal bend (flexura duodenojejunalis). The ascending part is crossed by the root of the mesentery of the jejunum. The superior mesenteric artery and vein pass between the anterior wall of the ascending duodenum and the body of the pancreas. The ascending part of the duodenum is in contact with the body of the pancreas from above, in front - with the root of the mesentery, behind - with the inferior vena cava, aorta and left renal vein.

When a person sits upright and takes a deep breath, the duodenum descends one vertebra. The most free parts are the bulb and the ascending part of the duodenum.

Duodenal ligaments. The hepatoduodenal ligament (lig. hepatoduodenale) is a double layer of peritoneum. It starts from the superoposterior wall of the upper part of the duodenum, reaches the porta hepatis, limiting the right edge of the lesser omentum, and is part of the anterior wall of the opening of the omental bursa (see Structure of the peritoneum). At the edge of the ligament on the right lies the common bile duct, on the left - the proper hepatic artery, behind - the portal vein, the lymphatic vessels of the liver (Fig. 243).

243. Contents of the hepatoduodenal ligament. 1 - hepar; 2 - omentum minus; 3 - v. portae; 4 - r. dexter a. hepaticae propriae; 5 - ductus hepaticus; 6 - a. cystica; 7 - ductus cysticus; 8 - ductus choledochus; 9 - a. hepatica propria; 10 - a. gastrica dextra; 11 - a. gastroduodenalis; 12 - a. hepatica communis; 13 - ventriculus; 14 - pancreas; 15 - duodenum; 16 - colon transversum; 17 - entry to for. epiploicum; 18 - vesica fellea.

The duodenal-renal ligament (lig. duodenorenale) is a wide plate of the peritoneum stretched between the postero-superior edge of the upper part of the intestine and the region of the renal hilum. The ligament forms the lower wall of the opening of the omental bursa.

The duodenal-transverse-colic ligament (lig. duodenocolicum) is the right part of the lig. gastrocolicum, passes between the transverse colon and the upper part of the duodenum. The right gastroepiploic artery for the stomach passes through the ligament.

Suspending ligament (lig. suspensorium duodeni) is a duplication of the peritoneum that covers the flexura duodenojejunalis and is attached at the beginning of the superior mesenteric artery and to the medial legs of the diaphragm. In the thickness of this ligament there are smooth muscle bundles.

Variants of the shape of the duodenum. The shape of the intestine described above occurs in 60% of cases, folded - in 20%, V-shaped - in 11%, C-shaped - in 3%, ring-shaped - in 6% (Fig. 244).

244. Variants of the shape of the duodenum.
1 - aorta; 2 - pancreas; 3 - flexura duodenojejunalis; 4 - a. mesenterica superior: 5 - duodenum; 6 - ren; 7 - v. cava inferior.

In newborns and children of the first year of life, the duodenum is relatively longer than in an adult; The lower horizontal part is especially long. The folds of the mucous membrane are low, the digestive glands of the intestine are well developed, its parts are not differentiated. The shape of the intestine is ring-shaped. A special feature is also the confluence of the pancreatic duct and the common bile duct, which flow into the initial part of the duodenum.

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✪ Anatomy of the small intestine

✪ Duodenum: topography, structure, functions, blood supply, regional lymph nodes

✪ Duodenum: where it is located, how it hurts, symptoms and treatment of the disease

✪ Inflammation of the duodenum: symptoms and treatment of the stomach

✪ anatomy of the stomach and duodenum

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Functions

However, most often the upper part of the duodenum begins at the level of the XII thoracic-I lumbar vertebra, then the intestine goes from left to right (superior bend) and down to the III lumbar vertebra (descending part), after which it makes a lower bend and follows parallel to the upper part, but narrower from right to left (horizontal part) to the spinal column at the level of the II lumbar vertebra (ascending part).

The junction of the duodenum and the jejunum, flexura duodenojejunalis, is located to the left of the spine, corresponding to the body of the II lumbar vertebra.

Syntopy

Top part The duodenum is adjacent to the quadrate lobe of the liver above and in front, as well as to the neck and body of the gallbladder. When the intestine shifts to the left, its initial section comes into contact with the lower surface of the left lobe of the liver. Between the upper part of the duodenum and the portal of the liver is the hepatoduodenal ligament, at the base of which the common bile duct passes on the right, the common hepatic artery on the left, and the portal vein in the middle and somewhat deeper.

The posteroinferior semicircle of the wall of the upper part of the duodenum, in the place where it is not covered by the peritoneum, is in contact with the common bile duct, portal vein, gastroduodenal and superior posterior pancreatic-duodenal arteries. The lower semicircle of this part of the duodenum is adjacent to the head of the pancreas.

Holotopy and peritoneal covering

Lies in regio hypochondriaca dextra.

The peritoneum covers the duodenum unevenly. Its upper part is devoid of peritoneal cover only in the region of the posteroinferior semicircle of the intestinal wall, that is, in the place where the intestine comes into contact with the head of the pancreas, portal vein, common bile duct and gastroduodenal artery. Therefore, we can assume that the initial section of the intestine is located mesoperitoneally. The same should be noted regarding the ascending part of the intestine. The descending and inferior parts have peritoneal cover only in front and are therefore located retroperitoneally.

In general, the duodenum is covered by peritoneum extraperitoneally.

Vessels and nerves of the duodenum

Blood supply

4 pancreatic-duodenal arteries:

The superior posterior pancreaticoduodenal artery arises from the initial section of the gastroduodenal artery behind the upper part of the duodenum and goes to the posterior surface of the pancreas, spiraling around the common bile duct.
The superior anterior pancreaticoduodenal artery arises from the gastroduodenal artery at the lower semicircle of the upper part of the duodenum and passes from top to bottom along the anterior surface of the head of the pancreas or is located in the groove formed by the descending part of the duodenum and the head of the pancreas.
The inferior posterior and inferior anterior pancreaticoduodenal arteries arise from the superior mesenteric artery or from the first two jejunal arteries. More often they arise with a common trunk from the first jejunal artery or from the superior mesenteric artery, less often - independently from the first and second jejunal arteries. Sometimes they can arise from the initial part of the middle colon, splenic or celiac arteries.
The inferior posterior pancreaticoduodenal artery passes along the posterior surface of the head of the pancreas and anastomoses with the superior posterior artery, forming the posterior arterial arch.
The inferior anterior pancreaticoduodenal artery passes along the anterior surface of the head of the pancreas or in the groove formed by the head of the pancreas and the descending part of the duodenum and, connecting with the superior anterior artery, forms the anterior arterial arch.

Numerous branches extend from the anterior and posterior pancreaticoduodenal arterial arches to the wall of the duodenum and to the head of the pancreas.

Venous drainage

It is carried out by the pancreatic-duodenal veins, which accompany the arteries of the same name, forming venous arches on the anterior and posterior surfaces of the head of the pancreas.

Lymphatic drainage

Lymphatic vessels that drain lymph from the duodenum are located on the anterior and posterior surfaces of the head of the pancreas. There are anterior and posterior pancreatic-duodenal lymph nodes.

, and concentrated bile and pancreatic enzymes than the epithelium of the distal small intestine. The structure of the epithelium of the duodenum also differs from the structure of the epithelium of the stomach.
In the submucosa of the duodenum (especially in its upper half) there are duodenal (Brunner's) glands, similar in structure to the pyloric glands of the stomach.

Duodenum, duodenum, is a section of the small intestine that originates directly from the stomach. It got its name due to the fact that its length is on average equal to 12 diameters of a human finger. Mostly it has a horseshoe shape, but ring-shaped and V-shaped ones are also found. The length of the duodenum is 25-30 cm, and the width is 4-6 cm, its concave edge wraps around the head.
The duodenum is an important organ of the digestive system, into which the ducts of the large digestive glands (and the pancreas) flow. Hormones are formed in its mucous membrane: secretin, pancreozymin-cholecystokinin, gastric inhibitory peptide, vasoactive intestinal peptide, motilin, enteroglucagon, etc. The duodenum has four parts:- Upper, pars superior,
- Descending, pars descendens;
- Horizontal, pars horizontalis;
and ascending, pars ascendens.
Top part, pars superior, s. bulbus, - the shortest, its length is
3-4 cm, diameter - up to 4 cm. Originates at the level of the second lumbar vertebra, goes back and to the right along the right surface of the spinal column, flexura duodeni superior.
The hepatoduodenal ligament, lig, runs from the porta hepatis to the upper part of the duodenum. hepatoduodenal, which contains: the common bile duct, the portal vein and the hepatic artery itself, lymphatic vessels and nerves. The ligament is important in surgical practice during operations in the pancreaticoduodenal region.
Descending part, pars descendens, - has a length of 9-12 cm, a diameter of 4-5 cm. It originates from the upper bend of the intestine, goes arcuate or vertical and reaches the level of the III-IV lumbar vertebrae, where it forms the lower bend, flexura duodeni inferior. In the middle part on the left, the common bile duct and the pancreatic duct flow into the intestine, forming longitudinal folds on the mucous membrane, plica longitudinalis duodeni, the major duodenal papilla, papilla duodeni major (Vateri).
Above it there may be a minor papilla, papilla duodeni minor; An additional pancreatic duct, ductus pancreaticus accessorius, opens on it. The outflow of bile and pancreatic juice is regulated by the closure muscle of the hepatopancreatic ampulla, m. sphincter ampullae (s. Oddi). The closure [sphincter] is formed by bundles of circular, oblique and longitudinal muscle fibers that intertwine and function independently of the intestinal muscles.
Horizontal part, pars horizontalis, - has a length of up to 9 cm, passes at the level of the III-IV lumbar vertebrae from right to left below the mesentery of the transverse colon.
The ascending part, pars ascendens, is 6-13 cm long, rises to the left edge of the I-II lumbar vertebrae, where the duodenocavum bend, flexura duodenojejunalis, is formed, the place of transition into the empty intestine. The bend is fixed by suspending the muscle of the duodenum, m. suspensorius duodeni s. m. (Treitzi). The muscle fibers arise from the circular layer of the intestine at the flexure site and ascend behind the pancreas, where they are woven into the fascia and muscle fibers of the left crus of the diaphragm. Due to its fixation on the left side of the second lumbar vertebra, the duodenocavum flexure is a cognitive landmark in surgery that helps to find the beginning of the jejunum.

Topography of the duodenum

The duodenum is in complex topographic-anatomical relationships with neighboring organs. It is located in the retroperitoneal space, mainly behind the stomach. The descending part of the intestine is located to the right of the spinal column, and the horizontal parts intersect its median plane. The ascending part of the duodenum is adjacent to the spine on the left.
Skeletotopia. The upper part is located at the level of the second lumbar vertebra (sometimes the XII thoracic vertebra). It intersects its median plane from right to left. The descending part of the intestine is adjacent to the right surface of the bodies of the II-III lumbar vertebrae and reaches the lower edge of the III lumbar vertebra. The horizontal part is located at the level of the III lumbar vertebra; it crosses its median plane from right to left in the transverse direction. The ascending part reaches the level of the second lumbar vertebra on the left and goes into the duodenal-empty flexure, flexura duodenojejunalis.
Syntopy. The following organs are adjacent to the upper part, pars superior, of the duodenum: on top - the right lobe of the liver, the common bile duct, the neck of the gallbladder and v. portaer, below - the head of the pancreas and part of the transverse colon; in front - the left lobe of the liver; behind - hepatoduodenal ligament, lig. hepatoduodenal.
Descending part, pars descendens, the duodenum is limited by the following organs: in front - ripples of the transverse colon; behind - the right kidney and partially the right ureter. On the posterior surface of the descending part, at its left edge, there are a joint bile duct, ductus choledohus, and a pancreatic duct, ductus pancreatics, which merge in the middle of the descending part. The head of the pancreas is adjacent to the descending part on the left, and the loops of the small intestine are on the right.
The horizontal part, pars horizontalis, is limited: from above - by the lower edge of the pancreas; from below - loops of the small intestine; behind - the abdominal aorta, on the right - the inferior vena cava; in front - loops of the small intestine.
The ascending part, pars ascendens, is limited: on the right - a. mesenterica superior, on top - by the lower surface of the body of the pancreas, the other sides - by loops of the small intestine. (The structure of the wall of the duodenum is considered together with the empty intestine and colon).

Abnormalities of the duodenum

Anomalies of the duodenum are most often presented in the form of a long and excessively mobile intestine or its individual parts and its reverse location (G. A. Zedgenidze, 1983). In this case, incomplete lengthening or increase in the mobility of the intestine can be limited only to the upper horizontal part, and sometimes affecting the descending part of the intestine. The elongated part of the intestine, due to the presence of its own mesentery, forms bends and loops that are unusual for it normally, which hang down and shift within wide boundaries.
The bend of the intestine with its atypical location can originate immediately after the bulb or in the area of the lower knee of the duodenum. In this case, the intestinal loop is turned not to the left, but anteriorly and to the right, as a result of which the duodenal-empty flexure is absent.
Blood supply. The blood supply to the duodenum is carried out by the superior and inferior pancreatoduodenal artery, aa. pancreaticoduodenals superior et inferior (Branch of a. gastroduodenalis and a. mesenterica superior). Venous outflow is carried out through the paired veins of the same name, vv. pancriaticoduodenales superior et inferior, into the superior mesenteric and splenic vein, and then into the portal vein, v. portae.
Lymph flows from the duodenum to the pyloric [portal], right gastric, hepatic, lumbar and superior mesenteric lymph nodes.
Innervation duodenum is carried out by branches of the vagus nerves, hepatic, gastric and superior mesenteric nerve plexuses.

The intestine, about 30 cm long, resembles a horseshoe, open to the left (Fig. 136). It is located to the right of the vertebral bodies. The intestine is divided into four parts: upper horizontal, descending, lower horizontal and ascending. The first part of the intestine is located at the level of the 1st lumbar vertebra, the descending part descends to the 3rd vertebra, the ascending part rises up and to the left to the left edge of the 2nd lumbar vertebra. Here the intestine, passing into the jejunum, forms a sharp bend (flexura duodenojejunalis). The duodenum is divided into two sections by the transversely located root of the mesentery of the transverse colon, belonging to the upper and lower floors of the abdominal cavity. Adjacent to the upper part of the intestine in front is the liver with the gall bladder, to the lower part there is the transverse colon and loops of the small intestine with the root of its mesentery, containing the upper mesenteric vessels. To the right of the duodenum is the hepatic inflection of the colon. On the left, the head of the pancreas is included in the bend of the intestine. Behind it are the gastroduodenal artery, the common bile duct, the inner part of the right kidney with its vessels and the inferior vena cava.

Rice. 136. Topography of the duodenum and pancreas.
1 - liver; 2 - stomach; 3 - pancreas: 4 - spleen; 5 - nonperitoneal fields - places of fixation of the colon and its mesentery; 6 - kidney; 7 - duodenum; 8 - a. mesenterica superior; 9 - a. pancreaticoduodenalis inferior; 10 - a. pancreaticoduodenalis superior; 11 - a. gastroduodenalis; 12 - a. coeliaca. A - duodenal nipple. 1 - ductus pancreaticus; 2 - papilla duodeni Vateri; 3 - ductus choledochus; 4 - lumen of the duodenum; 5 - pancreas.

The upper horizontal part of the duodenum is relatively mobile. On fluoroscopy, its initial part appears expanded and is defined as a bulb (bulbus duodeni). In the middle third, on the posterointernal wall of the descending part of the duodeni, there is an elevation on the mucosa called the papilla of Vater. The common bile duct and pancreatic duct open here.

The duodenum is an organ located retroperitoneally. However, only in front is it covered with peritoneum - within the left segment of the upper horizontal, descending and lower horizontal parts. The remaining parts of the intestine lie mesoperitoneally, as they are covered by a serous membrane on three sides. Due to the folds of the peritoneum, duodenal ligaments are formed. The hepatoduodenal ligament runs from the porta hepatis to the upper horizontal part of the intestine. In this ligament, the bile duct (ductus choledochus) passes on the right, the proper hepatic artery (a. hepatica propria) on the left, and the portal vein behind and between them. The ligament also contains lymphatic pathways and fibers of the sympathetic nervous system. Plicae duodenales superior et inferior are stretched from the posterior wall of the abdominal cavity to the flexura duodenojejunalis. The ligaments form pockets (recessus duodenojejunalis superior et inferior) of varying depths. They can be the site of internal abdominal hernias.

The blood supply to the duodenum is carried out through the superior and inferior pancreaticoduodenal arteries (aa. pancreaticoduodenal superior et inferior). The first vessel departs from the gastroduodenal artery and supplies the upper parts of the intestine; the second vessel is a branch of the superior mesenteric artery and approaches the lower parts of the intestine. The veins of the duodenum follow the course of the arteries. The lymphatic pathways of duodenum represent a single system with the pathways of lymph outflow from the pancreas. The innervation of the intestine is carried out by branches running along the blood vessels from the solar, superior mesenteric and hepatic plexuses.