The mesentery of the small intestine: what is it, location, structure, function, role in the development of diseases, structure

An important anatomical and functional element of the abdominal cavity is the mesentery of the small intestine. The duplication attaches the loops of the digestive tract to the posterior abdominal wall. The leaf structure physically supports the organ. Inside the fold are blood vessels, nerve fibers, lymphatic channels.

What is the mesenteric part in the small intestine

The double leaf of the peritoneum has a spiral configuration. The fixing duplication includes 6 bends:

• small intestinal duodenal;
• ileocecal-valve;
• hepatic;
• splenic;
• sigmoid;
• rectal.

The root of the mesentery of the small intestine extending from the posterior abdominal wall is 13-15 cm long. The body of the fixing process consists of a combination of peritoneal and fascial components.

The leaf duplication attributed to the internal organs is covered by the serous membrane. The anatomical and functional element of the abdominal cavity is divided into 2 sections - proximal and distal.

There is no clear border between the sites. In the mesentery lie the branches of the artery feeding the esophageal tube. The bloodstream forms arcade anastomoses - connecting elements between the vessels.

The intestinal trunk serves as the lymphatic collector of the organ, which flows into the thoracic duct in the region of the 2nd lumbar vertebra. The superior mesenteric plexus innervates the leaf duplication.

Structure

The basis of the mesentery is made up of muscle fibers covered with a serous membrane and mucous membrane. The first fits the fold from 3 outer sides fixing the small intestine in the anatomically correct position.

Only the narrow edge of the leaf-like duplication is free from serous covering. The membrane is attached to the smooth muscle fibers of the intestinal region by a sub-serous basis. The external muscular structures are located longitudinally.

The inner muscle layer has a circular configuration. The formation of the mesentery of the small intestine occurs in the 2nd month of embryogenesis. First, the muscular base is formed, then the serous membrane with the mucous membrane.

The organ epithelium forms a circular fold, covered with villi-receptors with crypts (functional tubular depressions). In the latter, the channels of the intestinal glands begin with lymphatic follicles.

Functions

The mesentery supports the loops of the small intestine, preventing prolapse or prolapse into the pelvic cavity. Other functions of the fixing leaf duplication:

1. Protecting the intestines from intense friction. The function is realized through the production of serous fluid.
2. Secretion of C-reactive protein compounds. Glycoprotein substances bind microbial polysaccharides. C-reactive protein activates the evacuation of lysophospholipids released when the membrane membranes of cells are damaged.
3. Transport of oxygen, trace elements, nutrients supplied with food. A large arterial vessel running in the mesentery of the small intestine delivers nutrients to the associated anatomical structures.
4. Control of the functions of the gastrointestinal tract. The neuroreceptors located in the leaf duplication transmit impulses from the brain to the innervated organs.
5. Immune support. The mesentery contains lymphatic channels that separate bacterial components from adjacent intestinal tracts, which regulate T-cell migration.

The C-reactive proteins produced by the organ are involved in numerous metabolic reactions, metabolic processes, and regulate the glycemic index of blood.

Physiologically active substances are used in laboratory diagnostics as markers of the acute phase of inflammatory processes. C-reactive glycoprotein proteins are important for the prevention of obesity, atherosclerosis, and diabetes mellitus.

Location of the mesentery

A leaf-like duplication is located in the lower segment of the abdominal cavity. The organ is located under the mesenteric part of the transverse colon of the digestive system.

The anatomical and functional element originates from the duodenal-thin bend to the left of the 2nd lumbar vertebra. The lower border of the organ is located in the right iliac cavity.

The duplication body extends from the 2nd lumbar vertebra to the large intestine. The organ ends in the region of the ilio-sacral joint. The fixation structure covers the mesenteric part of the small intestine with the right ureter.

The terminal section of the organ crosses the right large muscle of the lower back with the iliac vessels. In the pelvic cavity, the anatomical and functional element in men is adjacent to the bladder, in women - to the uterus with appendages.

Diseases of the mesenteric process of the small intestine

The organ is prone to congenital anomalies, neoplastic processes, and infectious lesions. Perhaps traumatic injury tissues of the mesenteric process of the small intestine.

With developmental delay in the early embryonic period, an anatomical anomaly occurs in the form of fusion of a leaf-like duplication with the tissues of the abdominal cavity. This pathology does not disrupt the function of the gastrointestinal tract, does not cause pain.

Duplication fusion increases the predisposition to bowel torsion. An anatomical anomaly is diagnosed by x-ray. Intrauterine malformations lead to disruption of the natural shape of the mesentery.

With a bruise of the epigastric surface, hernial pinching, a penetrating wound of the abdominal cavity, a traumatic damage to the leaf duplication of the small intestine occurs.

Pathological processes affect the serous sheets, vessels of the mesentery of the small intestine, nerve fibers. Superficial tears of organ tissues are not accompanied by clinical symptoms.

When the root of the leaf-like duplication is torn off the abdominal wall or intestinal loop, peritonitis occurs - internal hemorrhage with simultaneous release of intestinal contents into the cavity. The rupture of small blood vessels causes tissue necrosis or hematoma.

As a result of traumatic damage to the mesentery, in the absence of surgical intervention, a cyst with bloody contents is formed. Over time, complications arise in the form of:

• rupture of pathological education;
• suppuration;
• intestinal obstruction;
• infection of the digestive tract with pathogenic microflora.

Rupture of the cyst is accompanied by severe peritoneal symptoms that require urgent surgical intervention. Inflammatory diseases of the mesenteric process are common.

Infectious processes are caused by the penetration of conditionally pathogenic bacteria into the fixing fold from the gastric cavity or other parts of the gastrointestinal tract by the hematological or lymphatic route.

Thrombosis with embolism

A systemic disturbance of hemodynamics fixing the process of the small intestine leads to an acute blockage of the mesenteric vessels. Thromboembolism develops after unsuccessful surgery, traumatic damage to duplication.

The blockage of vascular channels is accompanied by the following symptoms:

• acute ischemic condition;
• intense pain reactions in the umbilical region;
• pulling sensations in the lumbosacral area;
• hyperthermia;
• weakness;
• nausea;
• bouts of vomiting;
• pronounced flatulence;
• diarrhea with blood inclusions in liquid feces.

With thrombosis of the mesenteric artery trunk, necrosis of the tissues of the small intestine develops. Blockage of the branches leads to the necrosis of the vascularization zone. An acute condition requires urgent surgical intervention.

The area of ​​the digestive tract, deprived of blood supply, acquires a pale color with ischemic infarction or black with hemorrhagic infarction. The walls of the gastrointestinal tract swell, thicken, thicken.

To eliminate a dangerous condition, an embolus or thrombectomy is performed - the removal of the formation clogging the bloodstream. Less commonly, mesenteric shunting is used, which provides for the creation of an additional hemodynamic pathway.

The procedure is indicated in the absence of signs of ischemic infarction of the small intestine. With the development of necrosis of the mesenteric tissues, the necrotic area is resected with the installation of an artificial strengthening element.

Tumor formations in the mesenteric process

Hyperplasias of the leaf duplication of the small intestine are rare. The frequency does not exceed 3-6% of the number of gastrointestinal diseases. A tumor of the mesentery of the small intestine is characterized by nonspecific symptoms.

There are anemic conditions, periodic internal bleeding, obstruction of the esophageal tube. Neoplastic processes of the leaf process are either benign or malignant.

The formation of a tumor focus causes impaired cell proliferation. At the initial stage of development of neoplastic education, clinical symptoms are absent or poorly expressed.

As the tumor grows, chronic fatigue, muscle weakness are felt, and appetite decreases. Mesenteric neoplasia is characterized by rapid weight loss and dyspeptic disorders.

Of the malignant processes of leaf duplication of the small intestine, adenocarcinoma, lymphoma, gastrointestinal tumor of the stromal type are widespread.

Risk factors include:

• hereditary adenomatous polyposis;
• Peitz-Jeghers-Touraine syndrome is a rare genetic disease characterized by the formation of multiple seals in the stomach cavity, small and large intestines;
• celiac disease - a biological predisposition to gluten intolerance, associated with an increased risk of T-cell lymphoma;
• Crohn's disease is a granulomatous recurrent-progressive inflammation of the digestive system.

Leaf duplication affects sclerotic or fibrous mesenteritis, which simulates the volumetric induration of the mesentery of the small intestine. The disease is differentiated by the lipid ring surrounding the vessels of the organ.

Mesenteric panniculitis

Pathology is a clear example of a pseudotumor process. Mesenteric panniculitis is an inflammation of the fatty layer of the mesenteric process. The etiology of the disease has not been clarified.

Possible reasons for the development of mesenteric panniculitis are:

• bruises of the epigastric surface;
• congenital or acquired immunodeficiency;
• systemic lesions by herpes infection, fungal cultures, microbial agents;
• lymphatic pathologies;
• destructive processes in the connective tissue structures;
• metabolic disorders - diabetes mellitus, obesity;
• malignant neoplasia of any localization;
• chronic sepsis;
• adhesions in the lumen of the small intestine.

Inflammation of the lipid membrane of the mesenteric vessels causes nonspecific and implicit symptoms. Disturbed by constant low-grade body temperature, spreading mild pain in the abdominal cavity, a feeling of bloating or bloating.

The tactic of therapy is focused on eliminating the factor provoking inflammation of the fat layer. Depending on the results of the diagnosis, antibiotics, fungicides, decongestants are prescribed.

The nodal seals causing compression of the vascular beds are removed with a traditional scalpel resection or endoscopically. Detoxification therapy involves the intake of enterosorbents, plasma hemosorption.

Mesenteric lymphadenitis

Inflammation of the mesenteric lymph nodes is manifested by an intense pain syndrome in the abdominal cavity, an increase in body temperature, and arrhythmic symptoms. The disease is provoked by infectious agents that penetrate into the structure of the small intestine from other organs.

Secondary inflammation of the mesenteric lymphatic channels is caused by respiratory, genitourinary or gastric bacteria. Less commonly, mesenteric lymphadenitis of viral genesis occurs. Suppressed immunity and concomitant inflammatory processes are considered to be predisposing factors.

The progression of the disease causes the formation of septic foci in the small intestine. Long-term course of the pathological process is fraught with the appearance of adhesions, strangulation obstruction of the esophageal tube. Such formations require surgical intervention.

As part of conservative etiotropic therapy, antibacterial drugs are used after determining the sensitivity of microbial agents. Anti-inflammatory, immunostimulating, analgesic drugs are prescribed symptomatically. With intense pain syndrome, perirenal blockade is indicated.

The mesentery of the small intestine is a functional element of the gastrointestinal tract that holds the esophagus in an anatomically correct position. The leaf duplication secretes C-reactive proteins, innervates and nourishes the organ.

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Small intestine anatomy.

Circulation diagram of the mesenteric part of the small intestine.

Literature:

1. Mesenteric lymphadenitis. Classification, treatment / S. WITH. Berebitsky - Penza, 2015, 318 p.
2. Lymphadenopathies: a guide for doctors / A. B. Bakirov, D. R. Vagapova, V. NS. Vagapova and others; ed. prof. V. AND. Nikulicheva - Ufa, Bashkortostan, 2011, 264 p.
3. Digestive system anatomy / I. V., Yakimov A. A., Nichiporuk G. And - publishing house "SpetsLit", 2016, 567 p.
4. Anatomical and morphological structure of connective tissue / Kozlov V. AND. - publishing house "Practical Medicine", 2014, 648 p.