Blood supply and innervation of the small intestine. Venous drainage from the small intestine. Lymphatic vessels of the small intestine. Lymph nodes of the small intestine. Innervation of the small intestine
Small intestine, intestinum tenue , located in the womb area (middle abdomen), downward from the stomach and transverse colon, reaching the entrance to the pelvic cavity.
Borders of the small intestine
The upper border of the small intestine is the pylorus of the stomach, and the lower border is the ileocecal valve at the point where it flows into the cecum.
Sections of the small intestine
The small intestine has the following sections: duodenum, jejunum and ileum. The jejunum and ileum, unlike the duodenum, have a well-defined mesentery and are considered the mesenteric part of the small intestine.
Duodenum
duodenum, is the initial section of the small intestine, located on the posterior wall abdominal cavity. The intestine begins from the pylorus and then goes around the head of the pancreas in a horseshoe shape. It has four parts: upper, descending, horizontal and ascending. The duodenum does not have a mesentery and is located retroperitoneally. The peritoneum is adjacent to the intestine in front, except for those places where it is crossed by the root of the transverse colon (pars descendens) and root of the mesentery of the small intestine (pars horizontalis). The initial section of the duodenum is its ampoule (“bulb”),ampulla, covered with peritoneum on all sides.
Vessels and nerves of the duodenum
The superior anterior and posterior pancreaticoduodenal arteries (from the gastroduodenal artery) and the inferior pancreaticoduodenal artery (from the upper mesenteric artery), which anastomose with each other and give duodenal branches to the intestinal wall. The veins of the same name drain into the portal vein and its tributaries. The lymphatic vessels of the intestine are directed to the pancreaticoduodenal, mesenteric (upper), celiac and lumbar lymph nodes. Innervation of the duodenum is carried out by direct branches of the vagus nerves and from the gastric, renal and superior mesenteric plexuses.
Jejunum
jejunum, located directly after the duodenum, its loops lie in the left upper part of the abdominal cavity.
Ileum
ileum, being a continuation of the jejunum, it occupies the lower right part of the abdominal cavity and flows into the cecum in the area of the right iliac fossa.
The jejunum and ileum are covered on all sides by peritoneum (lie intraperitoneally), which forms the outer serous membrane,tunica serosa, its walls, located on a thin subserous base,tela subserosa. Under the subserous base lies muscle membrane,tuni ca musculdris, followed by submucosa,tela submucosa. The last shell - mucous membrane,tunica mucosa.
Vessels and nerves of the jejunum and ileum
15-20 small intestinal arteries (branches of the superior mesenteric artery) approach the intestine. Venous blood flows through the veins of the same name into the portal vein. Lymphatic vessels flow into the mesenteric (upper) lymph nodes, from the terminal ileum into the ileocolic nodes. The wall of the small intestine is innervated by branches of the vagus nerves and the superior mesenteric plexus (sympathetic nerves).
Small intestine, intestinum tenue, (Greek enteron), has the shape of a tube, 5-6 meters long. It has three parts:
duodenum, duodenum
jejunum, jejunum
ileum, ileum.
The jejunum and ileum, which have a mesentery, are called the small intestine. mesenteric intestine. Most of the duodenum is located extraperitoneally and is amesenteric.
DUODENUM
Duodenum is the initial section of the small intestine; it has the shape of a horseshoe.
I. Holotopia: located in the right hypochondrium, in the right lateral and periumbilical regions.
II. Skeletotopia:
The upper part is projected at level I lumbar vertebra;
The descending part descends from level I to level III of the lumbar vertebrae;
The horizontal part is located at the level of the third lumbar vertebra;
The ascending part rises from level III to level II of the lumbar vertebrae.
III. Syntopy:
The upper part is in contact with the quadrate lobe of the liver, the neck of the gallbladder and below with the transverse colon;
The descending part is adjacent to the right kidney and is crossed in front by the mesentery of the transverse colon;
In the groove between the head of the pancreas and the descending part of the duodenum there passes the common bile duct, which opens into the descending part at about half its height;
Inside the horseshoe of the duodenum is the head of the pancreas;
behind the horizontal part are the aorta and the inferior vena cava; in front of it are the superior mesenteric artery and vein.
IV. Macroscopic structure of the organ- in the KDP there are:
1. four parts:
The upper part (in a living person its initial section is expanded - the bulb);
Descending part
Horizontal part
Rising part
2. three bends:
Upper bend of the duodenum (between the upper and descending parts);
The lower bend of the duodenum (between the descending and horizontal parts);
Duodenum-jejunal flexure (place of transition of the duodenum into the jejunum).
V. Microscopic structure of the organ:
Single-layer prismatic epithelium (intestinal type);
Intestinal villi: inside there is a milky (lymphatic) capillary, surrounded by a network of blood capillaries;
Single lymphoid follicles;
The submucosa is well expressed - the mucous membrane has folds: circular folds; only in the descending part is a longitudinal fold, which ends with the major papilla of the duodenum (Papilla of Vater), where the common bile duct and the pancreatic duct open; in 30% of cases, the minor duodenal papilla is found, where the accessory pancreatic duct opens.
Outer layer - longitudinal
3. outer shell - serous and adventitial; in relation to the peritoneum top part and the duodenum-jejunal flexure lie intraperitoneally, and the remaining sections lie retroperitoneally.
VI. Blood supply to the organ: The duodenum receives arterial blood from the following arteries:
A. pancreatoduodenalis superior from a.gastroduodenalis from a.hepatica communis (branch of truncus coeliacus from pars abdominalis aortae)
A. pancreatoduodenalis inferior from a.mesenterica superior (branch of pars abdominalis aortae)
The outflow of blood is carried out through the vv.pancreatoduodenalis superior et inferior into the v. system. portae.
VII. Innervation of the organ: Along the organ, nerve fibers form the so-called duodenal plexus, plexus duodenalis:
A) afferent innervation is provided by the anterior branches of the lower thoracic spinal nerves (spinal innervation); by rr.duodenales n.vagi (bulbar innervation);
B) sympathetic innervation is provided by fibers of the plexus duodenalis, which are formed from the plexus coeliacus along the arteries supplying the organ;
B) parasympathetic innervation is provided by the rr.duodenales n.vagi.
VIII. Lymph drainage: lymph outflow occurs in the nodi lymphatici pancreatoduodenales, pylorici, mesenterici superiores et coeliaci.
MESENTERIC PART OF THE SMALL INTESTINE
Mesenteric part of the small intestine includes the jejunum and ileum. Approximately 2/5 of the mesenteric part is the jejunum, the remaining 3/5 of its length is the ileum.
Jejunum begins at the level of the body of the second lumbar vertebra on the left as a continuation of the duodenum after the duodenum-jejunal flexure. Its loops lie in the left upper part of the abdominal cavity.
Ileum is a continuation of the jejunum. It occupies the lower right part of the abdominal cavity and ends in the region of the right iliac fossa, passing into the cecum.
The small intestine has two edges:
Mesenteric margin - the place of attachment of the mesentery;
The free edge is facing the abdominal wall.
Macroscopic structure of the jejunum and ileum:
1. mucous membrane, tunica mucosa:
The mucous membrane is lined with single-layer prismatic epithelium (intestinal type);
Intestinal villi cover the entire surface of the mucous membrane; in the jejunum they are longer and their density is greater than in the ileum;
Single lymphoid follicles - there are more of them in the jejunum;
Group lymphoid follicles (Peyer's patches) - there are more of them in the ileum;
The submucosa is well defined and the mucous membrane forms circular folds - especially numerous in the initial section of the jejunum; gradually they become lower and their length decreases (in the final section of the ileum the folds practically disappear).
2. muscular layer, tunica muscularis:
Inner layer - circular
Outer layer - longitudinal
3. outer shell - serous; In relation to the peritoneum, the jejunum and ileum lie intraperitoneal.
Blood supply: the jejunum and ileum receive arterial blood from a.pancreatoduodenalis inferior, aa.jejunales et ileales from a.mesenterica superior (branch of pars abdominalis aortae).
The outflow of blood is carried out through the veins of the same name in v. mesenterica superior and further into the v. system. portae.
Innervation: along the small intestine, nerve fibers form the so-called intestinal plexus, plexus intestinalis:
A) afferent innervation is provided by the anterior branches of the lower thoracic and upper lumbar spinal nerves (spinal innervation); by rr. intestinales n.vagi (bulbar innervation);
B) sympathetic innervation is provided by fibers of the plexus intestinalis, which are formed from the plexus coeliacus along the arteries supplying the organ;
B) parasympathetic innervation is provided by rr. intestinales n.vagi.
Lymph drainage: the outflow of lymph is carried out in the nodi lymphatici mesenterici superiores, coeliaci et ileocolici.
Structure
Small intestine is a narrowed section of the intestinal tube.
Small intestine is very long, representing the main part of the intestine and ranges from 2.1 to 7.3 meters in dogs. Suspended on a long mesentery, the small intestine forms loops that fill most of the abdominal cavity.
Small intestine comes out from the end of the stomach and is divided into three different sections: the duodenum, the jejunum and the ileum. The duodenum accounts for 10% of the total length of the small intestine, while the remaining 90% of the length of the small intestine consists of the jejunum and ileum.
Blood supply
The wall of the thin section is richly vascularized.
Arterial blood comes through the branches abdominal aorta- the cranial mesenteric artery, and to the duodenum also via the hepatic artery.
Venous drainage occurs in the cranial mesenteric vein, which is one of the roots of the portal vein of the liver.
Lymphatic drainage from the intestinal wall comes from the lymphatic sinuses of the villi and intraorgan vessels through the mesenteric (intestinal) lymph nodes into the intestinal trunk, which flows into the lumbar cistern, then into the thoracic lymphatic duct and the cranial vena cava.
Innervation
The nervous supply of the thin section is represented by the branches of the vagus nerve and postganglionic fibers of the solar plexus from the semilunar ganglion, which form two plexuses in the intestinal wall: intermuscular(Auerbach's) between the layers of the muscle membrane and submucosal(Meissner) in the submucosal layer.
Control of intestinal activity from the outside nervous system carried out both through local reflexes and through vagal reflexes with the involvement of the submucosal nerve plexus and intermuscular nerve plexus.
Intestinal function is regulated by the parasympathetic nervous system, the center of which is its medulla oblongata, from where the vagus nerve (10th pair of cranial nerves, respiratory-intestinal nerve) extends to the small intestine. Sympathetic vascular innervation regulates trophic processes in the small intestine.
The processes of local control and coordination of motility and secretion of the intestine and associated glands are of a more complex nature; nerves, paracrine and endocrine chemicals take part in them.
Topography
Intestinal lining
The functional features of the small intestine leave an imprint on its anatomical structure. Highlight mucous membrane And submucosal layer, muscular (external longitudinal and internal transverse muscles) And serous intestinal lining.
Mucous membrane
Mucous membrane forms numerous devices that significantly increase the suction surface.
These devices include circular folds, or Kirkring folds, in the formation of which not only the mucous membrane, but also the submucosal layer, and lint, which give the mucous membrane a velvety appearance. The folds cover 1/3 or 1/2 of the circumference of the intestine. The villi are covered with a special bordered epithelium, which carries out parietal digestion and absorption. The villi, contracting and relaxing, perform rhythmic movements with a frequency of 6 times per minute, due to which they act as a kind of pumps during suction.
In the center of the villus there is a lymphatic sinus, which receives fat processing products. Each villus from the submucosal plexus contains 1-2 arterioles, which break up into capillaries. Arterioles anastomose with each other and during absorption all capillaries function, while during a pause there are short anastomoses. Villi are thread-like outgrowths of the mucous membrane formed by loose connective tissue, rich in smooth myocytes, reticulin fibers and immunocompetent cellular elements, and covered with epithelium.
The length of the villi is 0.95-1.0 mm, their length and density decreases in the caudal direction, that is, in the ileum the size and number of villi are much smaller than in the duodenum and jejunum.
Histological structure
The mucous membrane of the thin section and villi is covered with a single-layer columnar epithelium, which contains three types of cells: columnar epithelial cells with a striated border, goblet exocrinocytes(secrete mucus) and gastrointestinal endocrinocytes.
The mucous membrane of the thin section is replete with numerous parietal glands - the common intestinal, or Lieberkühn's glands (Lieberkühn's crypts), which open into the lumen between the villi. The number of glands averages about 150 million (in the duodenum and jejunum there are 10 thousand glands per square centimeter of surface, and 8 thousand in the ileum).
The crypts are lined with five types of cells: epithelial cells with a striated border, goblet glandulocytes, gastrointestinal endocrinocytes, small borderless cells of the crypt bottom (stem cells of the intestinal epithelium) and enterocytes with acidophilic granules (Paneth cells). The latter secrete an enzyme involved in the breakdown of peptides and lysozyme.
Lymphoid formations
For duodenum characteristic tubular-alveolar duodenal, or Bruner's glands, which open into crypts. These glands are a continuation of the pyloric glands of the stomach and are located only on the first 1.5-2 cm of the duodenum.
The final segment of the thin section ( ileum) is rich in lymphoid elements, which lie in the mucous membrane at different depths on the side opposite to the attachment of the mesentery, and are represented by both single (solitary) follicles and their clusters in the form of Peyer's patches.
Plaques begin in the final part of the duodenum.
The total number of plaques is from 11 to 25, they are round or oval in shape, length from 7 to 85 mm, and width from 4 to 15 mm.
The lymphoid apparatus takes part in the digestive processes.
As a result of the constant migration of lymphocytes into the intestinal lumen and their destruction, interleukins are released, which have a selective effect on the intestinal microflora, regulating its composition and distribution between the thin and thick sections. In young organisms, the lymphoid apparatus is well developed, and the plaques are large.
With age, a gradual reduction of lymphoid elements occurs, which is expressed in a decrease in the number and size of lymphatic structures.
Muscularis
Muscularis represented by two layers of smooth muscle tissue: longitudinal And circular, and the circular layer is better developed than the longitudinal one.
The muscularis propria provides peristaltic movements, pendulum movements, and rhythmic segmentation that propel and mix the intestinal contents.
Serosa
Serosa- visceral peritoneum - forms the mesentery, on which the entire thin section is suspended. At the same time, the mesentery of the jejunum and ileum is better expressed, and therefore they are combined under the name mesenteric colon.
Functions
Digestion of food is completed in the small intestine under the action of enzymes produced by the wall ( liver And pancreas) and wall ( Lieberkühn and Brunner) glands, absorption of digested products into the blood and lymph, and biological disinfection of incoming substances.
The latter occurs due to the presence of numerous lymphoid elements enclosed in the wall of the intestinal tube.
The endocrine function of the small section is also great, which consists in the production by intestinal endocrinocytes of some biologically active substances(secretin, serotonin, motilin, gastrin, pancreozymin-cholecystokinin, etc.).
It is customary to distinguish three sections of the thin section:
- initial segment, or duodenum,
- middle segment, or jejunum,
- and the final segment, or ileum.
Duodenum
Structure
The duodenum is the initial section of the thin section, which is connected to the pancreas and the general bile duct and has the appearance of a loop facing caudally and located under the lumbar spine.
The length of the intestine is on average 30 cm or 7.5% of the length of the thin section. This section of the thin section is characterized by the presence of duodenal (Bruner's) glands and a short mesentery, as a result of which the intestine does not form loops, but forms four pronounced convolutions.
Topography
The cranial part of the intestine forms S-shaped, or sigmoid gyrus, which is located in the pylorus region, receives the ducts of the liver and pancreas and rises dorsally along the visceral surface of the liver.
Under right kidney the intestine turns caudally - this is cranial gyrus of the duodenum, and goes to descending part, which is located in the right iliac.
This part passes to the right of the root of the mesentery and under the 5-6 lumbar vertebrae passes to the left side transverse part, dividing the mesentery into two roots in this place, and forms caudal gyrus of the duodenum.
The intestine is then directed cranial to the left of the mesenteric root as ascending part. Before reaching the liver, it forms duodejejunal gyrus and passes into the jejunum. Thus, a narrow loop of the anterior root of the mesentery is formed under the spine, containing the right lobe of the pancreas.
Jejunum
Structure
The jejunum is the longest part of the small section and is about 3 meters, or 75% of the length of the small section.
The intestine got its name due to the fact that it has a half-dormant appearance, that is, it does not contain voluminous contents. The diameter exceeds the ileum located behind it and is distinguished by a large number of vessels passing through a well-developed mesentery.
Due to its considerable length, developed folds, numerous villi and crypts, the jejunum has the largest absorption surface, which is 4-5 times greater than the surface of the intestinal canal itself.
Topography
The intestine forms 6-8 skeins, which are located in the region of the xiphoid cartilage, the umbilical region, the ventral part of both ilia and the groins.
Ileum
Structure
The ileum is the final part of the thin section, reaching a length of about 70 cm, or 17.5% of the length of the thin section. Externally, the intestine is no different from the jejunum. This department is characterized by the presence large quantity lymphoid elements in the wall. The final section of the intestine has thicker walls and the highest concentration of Peyer's patches. This section runs straight under the 1st-2nd lumbar vertebrae from left to right and in the area of the right ilium flows into the cecum, connecting with it by a ligament. At the point where the ileum enters the cecum, the narrowed and thickened part of the ileum forms ileo-cecal valve, or ileal papilla, which has the appearance of a relief ring-shaped damper.
Topography
The name of this department small intestine received due to the topographic proximity to the iliac bones, to which it is adjacent.
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"Veles-Vet"
It is the section of the digestive tract between the stomach and large intestine. The small intestine is divided into three sections: duodenum, jejunum and ileum. The beginning and end of the small intestine are fixed by the root of the mesentery to the posterior wall of the abdominal cavity and have topographic constancy. Throughout the rest of the small intestine, the small intestine has a mesentery of varying widths. They are bordered on three sides by sections of the large colon, intestinum colon; above - transverse colon, colon transversum; on the right - the ascending colon, colon ascendens, on the left - the descending colon, colon descendens, passing into the sigmoid colon, colon sigmoideum.
The edge of the small intestine attached to the mesentery is called mesenteric, margo mesenterialis, the opposite is called free, margo liber. The diameter of the small intestine decreases from the initial section. This fact apparently explains the most common obstructive obstruction and delay foreign bodies precisely in the final section of the small intestine. The duodenum-jejunal flexure is usually well defined and has the shape of the letter “L”. To make it easier to find flexura duodenojejunalis, you can use Gubarev’s technique. To do this, the greater omentum with the transverse colon is taken into left hand, stretch and move slightly upward; fingers right hand they walk along the mesentery of the transverse colon to the spine, then slide off it to the left and grab the loop of the small intestine lying here. This will be the first, fixed loop of the small intestine.
^ There are extraorgan and intraorgan circulatory systems small intestine. The extraorgan arterial system is represented by the system of the superior mesenteric artery: its branches, arcades and vasa recta. In the thickness of the mesentery of the small intestine, the superior mesenteric artery runs, accompanied by the vein of the same name, from top to bottom from left to right, forming an arcuate bend, convexly directed to the left. It ends in the right iliac fossa with its terminal branch - a. ileocolica. Small intestinal branches (12-16) are divided into jejunal arteries, aa. jejunales, and ileointestinal, aa. ileales. Each of these arteries is divided into two branches: ascending and descending. The ascending branch anastomoses with the descending branch of the overlying artery, and the descending branch anastomoses with the ascending branch of the underlying artery, forming arches (arcades) of the first order.
^ Extraorgan veins of the small intestine begin to form from the straight veins into a system of venous arcades, which form the veins of the jejunum, vv. jejunales, ileum, vv. ileales, and ileocolic vein, v. ileocolica. All extraorgan veins of the small intestine merge to form the superior mesenteric vein, v. mesenterica superior.
^ Lymphatic vessels upon exiting the wall of the small intestine they enter the mesentery and are located in two layers corresponding to the two layers of the peritoneum. The draining lymphatic vessels have a distinct shape due to the presence of frequently located valves. On their way from the intestinal wall to the central lymph nodes located in the root of the mesentery along the superior mesenteric artery at the head of the pancreas, the lymphatic vessels are interrupted in the intermediate mesenteric lymph nodes. They are located in three rows: the first row of lymph nodes is located along the mesenteric edge of the intestine, the second is located at the level of the intermediate vascular arcades, and the third is along the main branches of the superior mesenteric artery.
^ Innervation of the small intestine carried out mainly by the superior mesenteric plexus, plexus mesentericus superior. It consists of vegetative - parasympathetic (n. vagus) and sympathetic (mainly from the ganglion mesentericum superius of the celiac plexus) branches.
^ Mesenteric sinuses (sinuses). Right mesenteric sinus (sinus), sinus mesentericus dexter, is limited above by the mesentery of the transverse colon, on the right - by the ascending colon, on the left and below - by the mesentery of the small intestine and the terminal ileum. The front is covered with a large oil seal. The right mesenteric sinus is delimited from the pelvis by the terminal portion of the small intestine and its mesentery; with the left mesenteric sinus it communicates above the duodenojejunal flexure of the small intestine.
^ Left mesenteric sinus , sinus mesentericus sinister, is located to the left and downward from the root of the mesentery of the small intestine. It is bounded above by the mesentery of the transverse colon, on the left by the descending colon and mesentery sigmoid colon, on the right is the mesentery of the small intestine. The left mesenteric sinus communicates widely with the pelvic cavity. The upper section of the left sinus is covered in front by the greater omentum, transverse colon and its mesentery.
^ Revision of abdominal organs . Performed to detect damaged organs in abdominal injuries and determine the source inflammatory process. The operation is performed from a midline incision sequentially and methodically. If there is blood in the abdominal cavity, the parenchymal organs are examined first: liver, spleen, pancreas. Examination of hollow organs. First of all, it is carried out when the contents of the stomach or intestines are found in the abdominal cavity after opening it. First, examine the anterior wall of the stomach, its pyloric section, the upper horizontal part of the duodenum, then the posterior wall of the stomach.
^ Examination of the small intestine carried out in strict sequence from the overlying fixed section (flexura duodenojejunalis) (Gubarev's technique). Methodicality consists in carefully examining each loop one by one along its free and mesenteric edges.
^ Colon examination start with revision of the ileocecal angle. The right and left flexures of the colon should be examined especially carefully. If the posterior wall of the ascending or descending colon is damaged, the resulting hematoma is opened through the corresponding lumbar sections, bringing drainage to the damaged colon.
^ The examination of the abdominal organs is completed examination of the upper parts of the rectum, the bottom of the bladder, the uterus with appendages, and the contours of both kidneys.
Enteroenteroanastomosis end to end. Separation of the mesentery from the intestine can be done in two ways: either parallel to the intestine at its edge at the level of the straight arteries, or wedge-shaped with preliminary ligation of the vessels closer to the root of the mesentery (extensive resections, intestinal tumors).
^ Bowel resection. Rigid hemostatic clamps are applied to the proximal and distal ends of the removed section of intestine in an oblique direction at an angle of 45° so that on the side opposite the mesenteric edge, the removed section of intestine would be slightly larger. Stepping 1.0-1.5 cm from the line of the intended resection and outward from the applied hard clamps, soft intestinal sponges are applied. The section of intestine to be removed is excised in an oblique direction parallel to the rigid clamps. After removing the excised area, the ends of the intestine are brought together. The formation of enteroenteroanastomosis begins with suturing its posterior wall with interrupted seromuscular sutures. Over the catgut suture, interrupted silk seromuscular sutures are placed on the anterior wall of the anastomosis. The hole in the mesentery is sutured with separate silk sutures.
^ Enteroenteroanastomosis side to side . Mobilization and resection of the intestine are carried out in the same way as in the previous method, only clamps are applied transversely to the intestine. The formation of the stump of the afferent and efferent sections of the intestine after resection is performed according to the Doyen method, which consists of the following steps: 1) ligation of the intestine with a catgut ligature under a clamp on the clamped area; 2) applying a purse-string suture at a distance of 1.5 cm from the dressing site; 3) immersion of the stump with tightening of the purse-string suture, over which a series of interrupted seromuscular sutures are applied. Application of enteroenteroanastomosis. The sutured intestinal segments are applied isoperistaltically one to the other. The walls of the intestinal loops for 8 cm are connected by serous-muscular nodules. At a distance of 0.75 cm from the suture line, the wall of one of the intestinal loops is cut. Having opened the intestinal lumen, the cavity of the intestinal loop is drained, after which the incision is extended in both directions parallel to the line of the serous-muscular suture, not reaching 1 cm from its edge. A continuous catgut suture is applied to the posterior edges of the anastomosis through all layers of the intestinal wall.
No. 66 Topography of the large intestine. Colostomy. The operation of applying an unnatural anus according to the Meidl method.
Colon is the final section of the digestive tract. It starts from the ileocecal junction in the right iliac region and ends with the rectum and anus. The large intestine is divided into three parts: the cecum, caecum, colon, colon, and rectum. The colon surrounds the loops of the small intestine in a U-shape and is divided into the ascending, transverse, descending and sigmoid colon. The place of transition of the ascending colon into the transverse colon is distinguished as the right colic flexure, flexura coli dextra, or hepatic curvature, and the place of transition of the transverse colon into the descending colon is identified as the left colic flexure, flexura coli sinistra, or splenic curvature.
^ The cecum is covered peritoneum from all. The ascending colon is located mesoperitoneally. Transverse
The colon is located intraperitoneally and has a well-defined mesentery, mesocolon transversum. The left flexure of the colon is located intraperitoneally and has a clearly defined mesentery. The descending colon is located mesoperitoneally. The sigmoid colon is located intraperitoneally and has a well-defined mesentery.
^ The main differences between the large and small intestines are as follows:
2. The large intestine differs from the small intestine in color. The large intestine is characterized by a grayish, ashen tint, and the small intestine is pinkish, brighter.
4. The wall of the colon between the muscle bands forms protrusions - haustrae coli, which are separated from each other by interceptions.
^ Arterial blood supply the ileocecal section is carried out by the ileocolic artery, a. ileocolica.
Artery of the appendix, a. appendicularis, usually passes behind the terminal part of the ileum, and then goes deep into the mesentery of the appendix. The arteries of the ascending colon are branches of a. colica dextra and a. Colica media. The arteries of the transverse colon arise from a. colica media and a. Colica sinistra. The arteries of the descending colon are branches of a. colica sinistra and a. sigmoidea Arteries of the sigmoid colon, aa. sigmoideae, go retroperitoneally, and then between the leaves of the mesentery, 2-4 branches in total. Superior rectal artery, a. Rectalis superior, the terminal branch of the inferior mesenteric artery, goes to the ampullary part of the rectum. It is connected by anastomosis with the inferior sigmoid and middle rectal arteries.
^ Venous bed The colon is composed of intrawall (intraorgan) and extrawall (extraorgan) venous vessels. The intraorgan veins of each layer of the intestinal wall, anastomosing with each other, form extraorgan straight veins at the mesenteric edge, which flow into the venous line running parallel to the course of the intestine. The extraorgan veins of the colon, which are the same as the arteries, form the superior and inferior mesenteric veins.
^ Lymphatic system The colon includes intraorgan lymphatic networks, lymph nodes and efferent lymphatic vessels. The intraorgan lymphatic networks of each layer of the intestinal wall merge and form drainage lymphatic vessels, which flow into the first stage lymph nodes located on the walls of the intestine and along its mesenteric edge. The lymph nodes subsequent stages are located in a chain along the branches of the superior and inferior mesenteric arteries.
Innervation colon is carried out by the sympathetic and parasympathetic parts of the autonomic nervous system and viscerosensitive nerve conductors. Sources autonomic innervation are the superior mesenteric plexus, plexus mesentericus superior, the inferior mesenteric plexus, plexus mesentericus inferior, and the intermesenteric plexus, plexus intermesentericus, connecting the previous ones, to which parasympathetic fibers from the truncus vagalis posterior are suitable.
^ Unnatural anus can be applied to any part of the colon. Most often it is applied to the sigmoid colon. The principle of its formation differs from colostomy in that a spur is created that prevents feces from entering the efferent limb of the intestine. Indications: rectal wounds, unremovable tumors, cicatricial narrowing of the rectum. Access - an oblique incision in the left iliac region parallel to and two transverse fingers above the inguinal ligament. The skin and aponeurosis of the external oblique abdominal muscle are dissected. The internal oblique and transverse muscles are divided. The peritoneum is incised and a loop of the sigmoid colon is removed. The parietal peritoneum is sutured to the skin along the edges of the surgical incision using separate interrupted silk sutures.
^ Creation of the Spur. The afferent and efferent loops of the sigmoid colon are sutured with interrupted silk seromuscular sutures. After 2-3 days, the withdrawn loop of intestine is opened in the transverse direction, as a result of which two openings are formed: the proximal one, which serves to drain fecal contents, and the distal one, for supplying drugs to the tumor and draining the products of the disintegrating tumor.
No. 67 Topography of the small and large intestines. Intestinal sutures, general requirements for intestinal sutures. Suturing of penetrating wounds of the small intestine.
The topography of the small and large intestines is discussed in questions No. 65, 66
^ The main differences are as follows: large intestine and small intestine :
1. The diameter of the large intestine is larger than that of the small intestine, and
It gradually decreases in the distal direction.
2. The large intestine differs from the small intestine in color. The large intestine is characterized by a grayish, ashen tint, and the small intestine is pinkish, brighter.
3. The longitudinal muscles are located unevenly in the wall of the colon, but form three separate muscle bands, teniae coli, running along the intestine.
4. The wall of the colon between the muscle bands forms protrusions - haustrae coli, which are separated from each other by interceptions.
5. On the surface of the peritoneal cover of the colon there are processes of the serous membrane, which are called omental processes, appendices epiploicae (omentales).
^ Under the term "intestinal suture" refers to all types of sutures placed on the wall of a hollow organ of the digestive tract (esophagus, stomach, intestines), as well as on other hollow organs that have peritoneal cover, muscular layer, submucosal layer and mucous membrane. General requirements for intestinal sutures: 1) compliance with asepsis, careful hemostasis and minimal tissue trauma, especially the mucous membrane and submucosal layer; 2) reliable tightness by ensuring wide contact of serous surfaces and adaptation of the remaining layers of the wall, especially during operations on the colon and biliary tract; 3) the use of absorbable material (catgut) when applying through or submerged sutures facing the lumen to the edges of the wound gastrointestinal tract, and non-absorbable - when applying seromuscular sutures; 4) in connection with the peristaltic movements of the intestine, sutures from absorbable suture material It is better to apply in the form of continuous, and from non-absorbable - in the form of nodal; 5) the intestinal suture is applied using round (stabbing) needles (straight or curved).
^ Suturing wounds of the small intestine . Access – midline laparotomy. For a small puncture wound, a purse-string seromuscular suture is placed around it, and when it is tightened, the edges of the wound are immersed into the intestinal lumen with tweezers. Incised wounds several centimeters long are sutured with a two-row suture: 1) internal through all layers of the intestinal wall - with catgut with the introduction of the edges according to Schmiden; 2) external seromuscular - interrupted silk sutures. To avoid narrowing of the intestine, longitudinal wounds are sutured in the transverse direction.
No. 68 Topography of the lumbar region. Fascia and cellular formations of the retroperitoneal space. Perinephric block.
Landmarks. Along the upper border of the lumbar region, the XI-XII ribs and their free ends are probed (the XII rib may sometimes be absent). The iliac crest is easily palpable below. The outer border coincides with a vertical line drawn from the end of the 11th rib to the iliac crest. Posterior to the highest point above the iliac crest is a depression known as the lumbar triangle. Upon palpation along the midline, the spinous processes of the two lower thoracic and all lumbar vertebrae are determined. Above the horizontal line connecting the iliac crests, the apex of the spinous process of the IV lumbar vertebra is palpated.
Topography. The skin is thickened and inactive. Subcutaneous tissue is poorly developed. The superficial fascia is well defined and gives off a deep fascial spur that separates subcutaneous tissue into two layers. The thoracolumbar fascia, fascia thoracolumbalis, forms cases for the muscles included in the lumbar region: mm. latissimus dorsi, obliquus externus et internus abdominis, serratus posterior inferior, erector spinae, transversus abdominis. First muscle layer The lumbar region consists of two muscles: the latissimus dorsi and the external oblique abdominal muscle. External oblique abdominal muscle, m. obllquus externus abdominis, flat, wide. Back bundles it is attached to the iliac crest. As a result, a lumbar triangle, trigonum lumbale, is formed between them. The triangle is bounded laterally by the edges of these muscles, and below by the iliac crest. Its bottom is formed by the internal oblique abdominal muscle. The lumbar triangle is a weak point of the lumbar region, where abscesses of the retroperitoneal tissue can penetrate and, in rare cases, come out lumbar hernia. Second muscle layer lumbar region are medial m. erector
Spinae, laterally at the top - m. serratus posterior inferior, below - m. obliquus internus abdominis. Serratus posterior inferior, m. Serratus posterior inferior, and internal oblique abdominal muscle, m. obliquus internus abdominis, constitute the lateral section of the second muscular layer of the lumbar region. Both muscles, facing each other with their edges, do not touch, as a result of which a three- or quadrangular-shaped space is formed between them, known as the lumbar quadrangle, tetragonum lumbale. Its sides are on top the lower edge of the inferior serratus muscle, on the bottom - the posterior (free) edge of the internal oblique abdominal muscle, on the inside - the lateral edge of the extensor spinae, on the outside and on top - the XII rib. Its bottom is the aponeurosis of the transverse abdominal muscle. Through it, ulcers of the retroperitoneal tissue can spread to the posterior abdominal wall.
^ Third muscle layer The lumbar region is represented by the transverse abdominal muscle, m. transversus abdominis. The deep surface of the aponeurosis and transverse abdominal muscle is covered with transverse fascia, fascia transversalis, which is part of the intra-abdominal fascia of the abdomen, fascia endoabdominalis, which medially forms cases for m. Quadratus lumborum and mm. psoas major et minor, called respectively fascia quadrata and fascia psoatis. In the upper part of the lumbar region, these fasciae, compacting, form two ligaments that pass into one another and are known as arcus lumbocostalis medialis et lateralis. Along the anterior surface of the quadratus muscle, under the fascia covering it in front, nn pass in an oblique direction from inside to outside from top to bottom. subcostalis, iliohypogastricus, ilioinguinalis, and in a similar gap on the anterior surface of the psoas major muscle there is n. genitofemoralis.
^ Retroperitoneal space , spatium retroperitoneale. The retroperitoneal space is located between the posterior wall of the abdominal cavity, covered with intraperitoneal fascia, and the parietal peritoneum. The retroperitoneal fascia, fascia retroperitonealis, begins from the fascia endoabdominalis and the parietal peritoneum at the level of the posterior axillary line, where the peritoneum from the side wall of the abdomen passes to the back. Fascia prerenalis passes as a common sheet in front of the fatty tissue covering the kidneys in front, at the top it forms a fascial sheath for the adrenal glands, fused with the corresponding part of the fascia retrorenalis, and is attached on the left to the fibrous tissue surrounding the superior mesenteric artery and the celiac trunk, and on the right - to the fascia sheath of the inferior cava veins The renal fascia, fascia retrorenalis, is also well developed at the level of the kidney. At the top, above the adrenal glands, it fuses with the prerenal fascia and is fixed to the fascial sheaths of the legs of the diaphragm. The fascia of the ascending and descending parts of the colon, or retrocolic fascia, fascia retrocolica, covers their extraperitoneal areas. The retrocolic fascia of the ascending colon is connected medially by numerous plates with the fascia covering the root of the mesentery of the small intestine, and the retrocolic fascia of the descending colon is lost in the tissue at its inner edge. Between the described fascial sheets in the retroperitoneal space, three layers of fiber should be distinguished: retroperitoneal, perinephric and peri-intestinal.
^ The first layer of retroperitoneal tissue , textus cellulosus retroperitonealis, is the retroperitoneal cellular space. Its anterior wall is formed by fascia retrorenalis, and the posterior wall by fascia-endoabdominalis.
^ Second layer of retroperitoneal tissue surrounds the kidney, located between the fascia retrorenalis and fascia prerenalis, and is the fatty capsule of the kidney, capsula adiposa renis, or paranephron, paranephron. The paranephron is divided into three sections: the upper - the fascial-cellular sheath of the adrenal gland, the middle - the own fatty capsule of the kidney and the lower - the fascial-cellular sheath of the ureter. Periureteric fiber, paraureterium, enclosed between the fascia preureterica and fascia retroureterica, extends along the ureter along its entire length.
^ Third layer of retroperitoneal tissue located behind the ascending and descending parts of the colon and is called paracolon.
Perinephric block. Indications: renal and hepatic colic, cholecystitis, dyskinesia biliary tract, pancreatitis, peritonitis, exacerbation peptic ulcer stomach, dynamic intestinal obstruction, shock due to severe injuries lower limbs. Position the patient on the healthy side on a bolster. Injection of a needle into the apex of the angle formed by the XII rib and the outer edge of the rectifier muscle; a long needle is inserted perpendicular to the surface of the body. Continuously injecting a 0.25% solution of novocaine, the needle is advanced to such a depth that there is a feeling of penetration of its end through the retrorenal fascia into the free cellular space. When the needle enters the perinephric tissue, the reverse flow of fluid stops. 60 - 80 ml of a 0.25% novocaine solution is injected into the perinephric tissue. The blockade is carried out on both sides.
№ 69 Topography of the kidneys, ureters and adrenal glands. Operative access to the kidneys and ureters.
The kidneys, surrounded by their own fatty capsule, are located in the upper part of the retroperitoneum on both sides of the spine. In relation to the posterior wall of the abdominal cavity, the kidneys lie in the lumbar region at the level of the XII thoracic, I and II lumbar vertebrae.
The right kidney, as a rule, lies lower than the left. The upper edge of the right kidney is located at the level of the eleventh intercostal space, and its gate is below the XII rib, while the upper edge of the left kidney is located at the level of the upper edge of the XI rib, and the gate is at the level of the XII rib. Relative to the spine, the renal gates are located at the level of the body of the first lumbar vertebra. The kidney has a bean-shaped shape. In each kidney, there are anterior and posterior surfaces, outer (convex) and inner (concave) edges, upper and lower ends. On its inner edge there is the renal hilum, hilum renalis. The upper poles of the kidneys move closer together, and the lower poles move apart. At the gate of the kidney, surrounded by fatty tissue, lie the renal artery, vein, branches of the renal nerve plexus, lymphatic vessels and nodes, and the pelvis, which passes down into the ureter. All of these formations make up the renal pedicle. In the renal pedicle behind there is the renal pelvis with the beginning of the ureter, slightly higher and anteriorly there is the renal artery, and even more anteriorly and higher the renal vein with the branches that form it. Above and slightly anterior and medial from the upper pole above each kidney in the capsule lies the adrenal gland, gl. suprarenalis, adjoining its posterosuperior surface to the diaphragm. In front of the right kidney are the liver (at the upper pole), the right flexure of the colon (outside) and the descending part of the duodenum (at the hilum). Adjacent to the left kidney with its capsule in front is the spleen - at the outer edge, the fundus of the stomach - at the upper pole, the tail of the pancreas - at the renal gate and the left bend of the colon - at the outer edge of the lower pole.
^ Renal arteries, aa. Renales, originate from the lateral walls of the abdominal aorta below the superior mesenteric artery at the level of the I-II lumbar vertebrae and go to the hilum of the kidneys. Aa depart from both renal arteries. suprarenales inferiores, and down - rr. ureterici. At the hilum of the kidney, the renal artery divides into two branches: the larger anterior and posterior. Branching in the renal parenchyma, they form two vascular systems: pre- and retropelvic. The nature of the intraorgan branching of the arteries allows us to distinguish 5 independent territories from the point of view of blood supply - 5 renal segments, to which the arterial branches of the same name are suitable. The anterior branch of the renal artery supplies blood to 4 of them, giving off to the arteries: the upper segment, a. segmenti superioris; upper anterior segment, a. segmenti anterioris superioris; lower anterior segment, a. segmenti anterioris inferioris, and the lower segment, a. segmenti inferioris. The posterior branch of the renal artery gives off only the artery of the posterior segment, a. segmenti posteri and rr. ureterici. Extraorgan branches of the renal arteries anastomose with each other, as well as with the vessels of the fatty capsule, adrenal gland and diaphragm.
^ Renal veins, vv. Renales, drain into the inferior vena cava. Part of the veins of the adrenal glands flows into the renal veins, and into the left renal vein, in addition, the left testicular (ovarian) vein, v. testicularis (ovarica) sinistra. The veins of the kidneys and their tributaries from the inferior vena cava system anastomose with the veins of the portal system, forming portocaval anastomoses with the splenic vein, gastric veins, superior and inferior mesenteric.
^ Lymphatic vessels of the kidney form two systems: superficial and deep. Superficial vessels are located in the fibrous capsule of the kidney, deep vessels are located in the kidney parenchyma.
^ Innervation of the kidneys carried out by the renal nerve plexus, plexus renalis. The sources of its formation are 4-6 branches of the celiac plexus, n. splanchnicus minor and the renal-aortic node.
^ Adrenal glands, glandulae suprarenales. The adrenal glands are located above the upper poles of the kidneys, at the level of the XI-XII thoracic vertebrae. They are enclosed in fascial capsules formed by the renal fascia, and rear surfaces adjacent to lumbar region diaphragm. The extraperitoneal surface of the liver is adjacent to the right adrenal gland in front, and the inferior vena cava is adjacent to its medial edge. The anterior surface of the left adrenal gland with its capsule is covered by the parietal peritoneum of the posterior wall of the omental bursa. In front and below, the left adrenal gland is adjacent to the pancreas with the splenic vessels.
^ Arterial blood supply each adrenal gland is carried out by the superior, middle and inferior adrenal arteries, aa. suprarenales superior, media et inferior, of which the upper is a branch of the inferior phrenic artery, the middle is a branch of the abdominal aorta, the lower is the first branch of the renal artery.
^ Venous drainage occurs according to a single v. suprarenalis. The left adrenal vein flows into the left renal vein, the right into the right renal vein or into the inferior vena cava . Innervation comes from the adrenal plexuses, which are formed by branches of the celiac, renal, phrenic and abdominal aortic plexuses, as well as branches of the celiac and vagus nerves.
^ Ureters, ureteres. The ureters are smooth muscle, somewhat flattened tubes that drain urine from the renal pelvis to the bladder, flowing into it near the neck at the corners of the base of the bladder triangle. There are two parts of the ureter: located retroperitoneally
The abdominal part, pars abdominalis, and the pelvic part, pars pelvina, lying in the subperitoneal tissue of the small pelvis. There are three narrowings: at the beginning, at the junction of the pelvis and the ureter; middle, at the level of the ureter crossing the iliac vessels and the border line, and lower, near the junction with the bladder. The ureters lie on m. The psoas with its fascia and in the lower lumbar region cross the vasa testicularia (ovarica), located inward and posterior to them.
^ In the blood supply of the lumbar ureter participate mainly
Renal and testicular (ovarian) arteries. The outflow of lymph is directed to the nodes located around the abdominal aorta and the inferior vena cava. Abdominal ureters innervated from plexus renalis, pelvic - from plexus hypogastricus.
No. 70 Topography of the abdominal aorta and inferior vena cava. Nerve plexuses, lymph nodes of the retroperitoneum. Operative access to the kidneys and ureters
Small intestine: sections, innervation, blood supply, lymphatic drainage.
Intestinum tenue, small intestine, begins at the pylorus and, having formed a whole series of loop-shaped bends along the way, ends at the beginning of the large intestine. In a living person, the length of the small intestine does not exceed 2.7 m and is extremely variable. In the small intestine, mechanical (promotion) and further chemical processing of food takes place under conditions of an alkaline reaction, as well as the absorption of nutrients.
The small intestine is divided into three sections: 1) duodenum, duodenum, - the section closest to the stomach, 25 - 30 cm long; 2) jejunum, jejunum, which accounts for 2/5 of the small intestine minus duodenum, and 3) ileum, ileum, the remaining 3/5
Innervation, blood supply, lymphatic drainage: Arteries of the small intestine, aa. intestinales jejunales et ileales, come from a. mesenterica superior. Duodenum feeds from aa. pancreaticoduodenales superiores (from a. gastroduodenalis) and from aa. panereaticoduodenales inferiores (from a. mesenterica superior). Venous blood flows through the veins of the same name into v. portae.
Lymphatic vessels carry lymph in the nodi lymphatici coeliaci et mesenterici (see section on the lymphatic system).
Innervation from the autonomic nervous system. The intestinal wall contains three nerve plexus: subserous, plexus subserosus, musculointestinal, plexus myentericus, and submucosal, plexus submucosus. The feeling of pain is transmitted through the sympathetic pathways; peristalsis and secretion decrease. N. vagus enhances peristalsis and secretion.
35. Small intestine: topography and structural features of the wall of different sections. Duodenum, duodenum, bends around the head of the pancreas in a horseshoe shape. There are four main parts in it: 1) pars superior is directed at the level of the first lumbar vertebra to the right and back and, forming a downward bend, flexura duodeni superior, passes into 2) pars descendens, which descends, located to the right of the spinal column, to the third lumbar vertebra ; here the second turn occurs, flexura duodeni inferior, with the intestine directed to the left and forming 3) pars horizontdlis (inferior), running transversely in front of v. cava inferior and aorta, and 4) pars ascendens, rising to the level of the I-II lumbar vertebra on the left and in front. Topography of the duodenum. On its way, the duodenum fuses with the head of the pancreas along the inner side of its bend; in addition, pars superior is in contact with the quadrate lobe of the liver, pars descendens is in contact with the right kidney, pars horizontalis passes between a. and v. mesentericae seperiores in front and aorta and v. cava inferior - behind. Duodenum does not have a mesentery and is only partially covered by peritoneum, mainly in front. The relationship to the peritoneum of the area closest to the pylorus (for about 2.5 cm) is the same as the outlet part of the stomach. The anterior surface of the pars descendens remains uncovered by the peritoneum in its middle section, where the pars aescendens is intersected anteriorly by the root of the mesentery of the transverse colon; The pars horizontalis is covered with peritoneum in front, with the exception of a small area where the duodenum is crossed by the root of the mesentery of the small intestine, which contains the vasa mesenterica superiores. However, duodenum can be classified as extraperitoneal organs. When the pars ascendens duodeni passes into the jejunum on the left side of the I or, more often, II lumbar vertebra, a sharp bend of the intestinal tube, flexura duodenojejunalis, is obtained, with the initial part of the jejunum directed downward, forward and to the left. Flexura duodenojejunalis, due to its fixation on the left side of the II lumbar vertebra, serves as an identification point during surgery to locate the beginning of the jejunum.
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