Middle floor of the abdominal cavity. Peritoneum, structure, functions. Abdomen. And on the lower floor they are located

Peritoneum, peritoneum, It is a closed serous sac, which only in women communicates with the outside world through the very small abdominal opening of the fallopian tubes. Like any serous sac, the peritoneum consists of two layers: parietal, parietal, peritoneum parietale, and visceral, peritoneum viscerale. The first lines the abdominal walls, the second covers the insides, forming their serous cover over a greater or lesser extent. Both leaves are in close contact with each other; between them, when the abdominal cavity is not opened, there is only a narrow gap called the peritoneal cavity, cavitas peritonei, which contains a small amount of serous fluid, moisturizing the surface of the organs and thus facilitating their movement around each other. When air enters during an operation, or autopsy, or when pathological fluids accumulate, both layers diverge and then the peritoneal cavity takes on the appearance of a real, more or less voluminous cavity.

Parietal peritoneum Lines the anterior and lateral walls of the abdomen with a continuous layer from the inside and then continues to the diaphragm and posterior abdominal wall. Here it meets the viscera and, wrapping itself around the latter, directly passes into the visceral peritoneum covering them. Between the peritoneum and the walls of the abdomen there is a connective tissue layer, usually with a greater or lesser content of adipose tissue, tela subserosa - subperitoneal tissue, which is not equally expressed everywhere. In the area of the diaphragm, for example, it is absent; on the posterior wall of the abdomen it is most developed, covering the kidneys, ureters, adrenal glands, abdominal aorta and the inferior vena cava with their branches.

Along the anterior abdominal wall over a large area, the subperitoneal tissue is weakly expressed, but below, in the regio pubica, the amount of fat in it increases, the peritoneum here connects with the abdominal wall more loosely, due to which the bladder, when stretched, pushes the peritoneum away from the anterior abdominal wall and its anterior the surface at a distance of about 5 cm above the pubis comes into contact with the abdominal wall without the mediation of the peritoneum. The peritoneum in the lower part of the anterior abdominal wall forms five folds converging towards the navel, umbilicus; one unpaired middle one, plica umbilicalis mediana, and two paired ones, plicae umbilicales mediales and plicae umbilicales laterales. The listed folds are delimited on each side above inguinal ligament two fossae inguinales related to the inguinal canal. Immediately under the medial part of the inguinal ligament there is a fossa femoralis, which corresponds to the position of the internal ring of the femoral canal.

Up from the navel, the peritoneum passes from the anterior abdominal wall and diaphragm to the diaphragmatic surface of the liver in the form of a falciform ligament, lig. falciforme hepatis, between the two leaves of which in its free edge there is a round ligament of the liver, lig. teres hepatis (overgrown umbilical vein). The peritoneum behind the falciform ligament from the lower surface of the diaphragm wraps onto the diaphragmatic surface of the liver, forming the coronary ligament of the liver, lig. coronarium hepatis, which at the edges has the appearance of triangular plates called triangular ligaments, lig. triangulare dextrum et sinistrum.

From the diaphragmatic surface of the liver, the peritoneum bends through the lower sharp edge of the liver onto the visceral surface; from here it extends from the right lobe to the upper end of the right kidney, forming lig. hepatorenale, and from the gate - to the lesser curvature of the stomach in the form of a thin lig. hepatogastricum and to the part of duodeni closest to the stomach in the form of lig. hepatoduodenal. Both of these ligaments are duplications of the peritoneum, since in the area of the hilum of the liver there are two layers of peritoneum: one going to the hilum from the anterior part of the visceral surface of the liver, and the second from its posterior part. Lig. hepatoduodenal and lig. hepatogastricum, being a continuation of one another, together constitute the lesser omentum, omentum minus. On the lesser curvature of the stomach, both layers of the lesser omentum diverge: one layer covers the anterior surface of the stomach, the other covers the posterior surface. At the greater curvature, both layers converge again and descend down in front of the transverse colon and loops of the small intestine, forming the anterior plate of the greater omentum, omentum majus. Having gone down, the leaves of the greater omentum are folded back up at a greater or lesser height, forming its posterior plate (the greater omentum thus consists of four leaves). Having reached the transverse colon, the two leaves that make up the posterior plate of the greater omentum fuse with the colon transversum and its mesentery and, together with the latter, then go back to the margo anterior of the pancreas; from here the leaves disperse; one is up, the other is down. One, covering the anterior surface of the pancreas, goes up to the diaphragm, and the other, covering the lower surface of the gland, passes into the mesentery of the colon transversum. In an adult, with complete fusion of the anterior and posterior plates of the greater omentum with the colon transversum on the tenia mesocolica, 5 leaves of the peritoneum are thus fused: four leaves of the omentum and the visceral peritoneum of the intestine. Let us now trace the course of the peritoneum from the same layer of the anterior abdominal wall, but not in the upward direction to the diaphragm, but in the transverse direction.

From the anterior abdominal wall, the peritoneum, lining the side walls of the abdominal cavity and moving to the posterior wall on the right, surrounds the caecum with its vermiform appendix on all sides; the latter receives the mesentery - mesoappendix. The peritoneum covers the colon ascendens in front and from the sides, then the lower part of the anterior surface of the right kidney, passes in the medial direction through m. psoas and ureter and at the root of the mesentery of the small intestine, radix mesenterii, bends into the right leaf of this mesentery. Having supplied the small intestine with a complete serous cover, the peritoneum passes into the left layer of the mesentery; at the root of the mesentery, the left leaf of the latter passes into the parietal leaf of the posterior abdominal wall, the peritoneum covers further to the left the lower part of the left kidney and approaches the colon descendens, which belongs to the peritoneum, as well as the colon ascendens; then the peritoneum on the side wall of the abdomen again wraps onto the anterior abdominal wall. In order to more easily assimilate complex relationships, the entire peritoneal cavity can be divided into three areas, or floors:

the upper floor is bounded above by the diaphragm, below by the mesentery of the transverse colon, mesocolon transversum;
the middle floor extends from the mesocolon transversum down to the entrance to the pelvis;
the lower floor begins from the line of entry into the small pelvis and corresponds to the pelvic cavity, which ends downward in the abdominal cavity.

Upper floor of the peritoneal cavity is divided into three bursae: bursa hepatica, bursa pregastrica and bursa omentalis. Bursa hepatica covers the right lobe of the liver and is separated from the bursa pregastrica by lig. falciforme hepatis; at the back it is limited by lig. coronarium hepatis.

In the depths of the bursa hepatica, iodine of the liver, the upper end of the right kidney with the adrenal gland is palpated. Bursa pregastrica covers the left lobe of the liver, the anterior surface of the stomach and the spleen; the left part of the coronary ligament runs along the posterior edge of the left lobe of the liver; The spleen is covered on all sides by peritoneum, and only in the area of the hilum does its peritoneum pass from the spleen to the stomach, forming lig. gastrolienale, and on the diaphragm - lig. phrenicolenale.

Bursa omentalis, omental bursa, It is a part of the general cavity of the peritoneum, lying behind the stomach and lesser omentum. The lesser omentum, omentum minus, includes, as stated, two peritoneal ligaments: lig. hepatogastricum, going from the visceral surface and gate of the liver to the lesser curvature of the stomach, and lig. hepatoduodenale, connecting the porta hepatis with the pars superior duodeni. Between the leaves lig. hepatoduodenale pass through the common bile duct (right), common hepatic artery (left) and portal vein (posteriorly and between these formations), as well as lymphatic vessels, nodes and nerves. The cavity of the omental bursa communicates with the general cavity of the peritoneum only through a relatively narrow foramen epiploicum. Foramen epiploicum is limited above by the caudate lobe of the liver, in front - by the free edge of the lig. hepatoduodenale, below - top part duodenum, behind - a sheet of peritoneum covering the inferior vena cava passing here, and more outward - a ligament passing from the posterior edge of the liver to the right kidney, lig. hepatorenal. The part of the omental bursa directly adjacent to the omental opening and located behind the lig. hepatoduodenale, is called the vestibule - vestibulum bursae omentalis; above it is limited by the caudate lobe of the liver, and below by the duodenum and the head of the pancreas. The upper wall of the omental bursa is the lower surface of the caudate lobe of the liver, and the processus papillaris hangs in the bursa itself.

The parietal layer of the peritoneum, forming the posterior wall of the omental bursa, covers the aorta, inferior vena cava, pancreas, left kidney and adrenal gland located here. Along the anterior edge of the pancreas, the parietal layer of peritoneum extends from the pancreas and continues forward and downward as the anterior layer of the mesocolon transversum or, more precisely, the posterior plate of the greater omentum, fused with the mesocolon transversum, forming the lower wall of the omental bursa. The left wall of the omental bursa is made up of ligaments of the spleen: gastrosplenic, lig. gastrolienale, and diaphragmatic-splenic, lig. phrenicosplenicum. The greater omentum, omentum majus, hangs down from the colon transversum in the form of an apron, covering the loops of the small intestine for a greater or lesser extent; It got its name from the presence of fat in it. It consists of 4 layers of peritoneum, fused in the form of plates. The anterior plate of the greater omentum are two layers of peritoneum, extending down from the greater curvature of the stomach and passing in front of the colon transversum, with which they grow together, and the transition of the peritoneum from the stomach to the colon transversum is called lig. gastrocolicum. These two leaves of the omentum can descend in front of the loops of the small intestine almost to the level of the pubic bones, then they bend into the posterior plate of the omentum, so that the entire thickness of the greater omentum consists of four leaves; the omentum leaves do not normally fuse with the loops of the small intestines. Between the leaves of the anterior plate of the omentum and the posterior leaves there is a slit-like cavity, communicating at the top with the cavity of the omental bursa, but in an adult the leaves usually grow together with each other, so that the cavity of the greater omentum is obliterated over a large area. Along the greater curvature of the stomach, the cavity sometimes continues in adults for a greater or lesser extent between the leaves of the greater omentum. In the thickness of the greater omentum there are lymph nodes, nodi lymphatici omentales, which drain lymph from the greater omentum and the transverse colon.

Middle floor of the peritoneal cavity becomes visible if the greater omentum and transverse colon are lifted upward.

Using the ascending and descending colons on the sides and the mesentery of the small intestines in the middle as the boundaries, it can be divided into four sections: between the side walls of the abdomen and the colon ascendens and descendens there are the right and left lateral canals, canales laterales dexter et sinister; the space covered by the colon is divided by the mesentery of the small intestine, running obliquely from top to bottom and from left to right, into two mesenteric sinuses, sinus mesentericus dexter and sinus mesentericus sinister. On the posterior parietal layer of the peritoneum there are a number of peritoneal fossae, which are of practical importance, since they can serve as a site for the formation of retroperitoneal hernias. At the junction of the duodenum and the jejunum, small pits are formed - depressions, recessus duodenalis superior et inferior. These pits are limited on the right by the bend of the intestinal tube, flexura duodenojejunalis, on the left by the fold of the peritoneum, plica duodenojejunalis, which runs from the apex of the bend to the posterior abdominal wall of the abdomen immediately below the body of the pancreas and contains v. mesenterica inferior.

In the area of the transition of the small intestine to the large intestine there are two pits: recessus ileocaecalis inferior et superior, below and above plica ileocaecalis, passing from the ileum to the medial surface of the caecum. The depression in the parietal layer of the peritoneum, in which the caecum lies, is called the fossa of the cecum and is noticeable when the cecum and the nearest section of the ileum are pulled upward. The resulting fold of peritoneum between the surface of m. iliacus and the lateral surface of the caecum is called plica caecalis. Behind the caecum, in the fossa of the cecum, there is sometimes a small opening leading to the recessus retrocaecalis, extending upward between the posterior abdominal wall and the colon ascendens. On the left side there is a recessus intersigmoideus; this fossa is noticeable on the lower (left) surface of the mesentery of the sigmoid colon, if it is pulled upward. Lateral to the descending colon there are sometimes peritoneal pouches - sulci paracolici. Above, between the diaphragm and the flexura coli sinistra, stretches a fold of the peritoneum, lig. phrenicocolicum; it is located just under the lower end of the spleen and is also called the spleen sac.

Ground floor. Descending into the pelvic cavity, the peritoneum covers its walls and the organs lying in it, including the genitourinary ones, so the relationships of the peritoneum here depend on gender. The pelvic section of the sigmoid colon and the beginning of the rectum are covered with peritoneum on all sides and have a mesentery (located intraperitoneally). Middle section The rectum is covered with peritoneum only from the anterior and lateral surfaces (mesoperitoneal), and the lower one is not covered with it (extraperitoneal). Passing in men from the anterior surface of the rectum to the posterior surface of the bladder, the peritoneum forms a depression located behind the bladder, excavatio rectovesicale. When the bladder is unfilled, on its superoposterior surface the peritoneum forms a transverse fold, plica vesicalis transversa, which smoothes out when the bladder is filled.

In women, the course of the peritoneum in the pelvis is different due to the fact that between the bladder and rectum there is the uterus, which is also covered with peritoneum. As a result, in the pelvic cavity in women there are two peritoneal pockets: excavatio rectouterina - between the rectum and the uterus and excavatio vesicouterina - between the uterus and the bladder. In both sexes, there is a prevesical space, spatium prevesicale, formed in front by the fascia transversalis, which covers the transverse abdominal muscles behind, and by the bladder and peritoneum behind. When the bladder is filled, the peritoneum moves upward, and the bladder is adjacent to the anterior abdominal wall, which allows the bladder to be penetrated through its anterior wall during surgery without damaging the peritoneum. The parietal peritoneum receives vascularization and innervation from the parietal vessels and nerves, and the visceral peritoneum - from the vessels and nerves that branch in the organs covered by the peritoneum.

Peritoneum, a thin serous membrane with a smooth, shiny, uniform surface, covers the walls of the abdominal cavity, cavitas abdominis, and partially the pelvis, organs located in this cavity. The surface area of the peritoneum is about 20,400 cm 2 and is almost equal to the area of the skin. The peritoneum is formed by the lamina propria, the serous membrane and the single layer covering it. squamous epithelium- mesothelium, mesothelium.

lining the walls of the abdomen is called the parietal peritoneum, peritoneum parietale; the peritoneum covering the organs is the visceral peritoneum, peritoneum viscerale. Moving from the walls of the abdominal cavity to the organs and from one organ to another, the peritoneum forms ligaments, ligamenta, folds, plicae, mesenteries, mesenterii.

Due to the fact that the visceral peritoneum covering one or another organ passes into the parietal peritoneum, most organs are fixed to the walls of the abdominal cavity. The visceral peritoneum covers the organs in different ways: on all sides (intraperitoneal), on three sides (mesoperitoneal) or on one side (retro- or extraperitoneal). Organs covered with peritoneum on three sides, located mesoperitoneally, include the partially ascending and descending sections, and the middle part.

Organs located extraperitoneally include (except for its initial section), the pancreas, adrenal glands, .

Organs located intraperitoneally have a mesentery connecting them with the parietal.

Mesentery is a plate consisting of two connected layers of the peritoneum of the duplication. One - free - edge of the mesentery covers the organ (intestine), as if suspending it, and the other edge goes to the abdominal wall, where its leaves diverge into different sides in the form of parietal peritoneum. Usually between the layers of the mesentery (or ligament) blood vessels, lymphatic vessels and nerves approach the organ. The place where the mesentery begins on the abdominal wall is called the root of the mesentery, radix mesenterii; approaching an organ (for example, the intestine), its leaves diverge on both sides, leaving a narrow strip at the point of attachment - the extraperitoneal field, area nuda.

The serous cover, or serous membrane, tunica serosa, is not directly adjacent to the organ or abdominal wall, but is separated from them by a layer of connective tissue subserosa, tela subserosa, which, depending on its location, has varying degrees of development. Thus, the subserosal base under the serous membrane of the liver, diaphragm, and upper part of the anterior wall of the abdomen is poorly developed and, conversely, significantly developed under the parietal peritoneum lining the posterior wall of the abdominal cavity; for example, in the region of the kidneys, etc., where the peritoneum is very movably connected to the underlying organs or to their parts.

The peritoneal cavity, or peritoneal cavity, cavitas peritonealis, is closed in men, and in women through the fallopian tubes, the uterus and communicates with external environment. The peritoneal cavity is a slit-like space of complex shape, filled with a small amount of serous fluid, liquor peritonei, moisturizing the surface of the organs.

The parietal peritoneum of the posterior wall of the abdominal cavity delimits the peritoneal cavity from the retroperitoneal space, spatium retroperitoneale, in which the retroperitoneal organs, organa retroperitonealia, lie. In the retroperitoneal space, behind the parietal peritoneum, there is the retroperitoneal fascia, fascia retroperitonealis.

The extraperitoneal space, spatium extraperitoneale, is also the retropubic space, spatium retropubicum.

Peritoneal cover and peritonealfolds. The anterior parietal peritoneum, peritoneum parietale anterius, forms a series of folds on the anterior wall of the abdomen. Along the midline there is a median umbilical fold, plica umbilicalis mediana, which stretches from the umbilical ring to the apex; This fold contains a connective tissue cord, which is an obliterated urinary duct, urachus. From the umbilical ring to the lateral walls of the bladder there are medial umbilical folds, plicae umbilicales mediales, in which cords of the empty anterior sections of the umbilical arteries are embedded. Outside these folds are the lateral umbilical folds, plicae umbilicales laterales. They stretch from the middle of the inguinal ligament obliquely upward and inward, towards the back. These folds contain the inferior epigastric arteries, aa. epigastricae inferiores, which nourish the rectus abdominis muscles.

At the base of these folds, pits are formed. On both sides of the median umbilical fold, between it and the medial umbilical fold, above the upper edge of the bladder, there are supravesical fossae, fossae supravesicales. Between the medial and lateral umbilical folds are the medial inguinal fossae, fossae inguinales mediates; outward from the lateral umbilical folds lie the lateral inguinal fossae, fossae inguinales laterales; these pits are located against the deep inguinal rings.

A triangular section of the peritoneum, located above the medial inguinal fossa and bounded on the medial side by the edge of the rectus abdominis muscle, with the lateral - lateral umbilical fold and below - the inner part of the inguinal ligament, is called the inguinal triangle, trigonum inguinale.

The parietal peritoneum, covering the anterior abdomen above the umbilical ring and the diaphragm, passing to the diaphragmatic surface of the liver, forms the falciform (suspensory) ligament of the liver, lig. falciforme hepatis, consisting of two layers of peritoneum (duplication), located in the sagittal plane. In the free lower edge of the falciform ligament there passes a cord of the round ligament of the liver, lig, teres hepatis. The leaves of the falciform ligament pass posteriorly into the anterior layer of the coronary ligament of the liver, lig. coronarium hepatis. It represents the transition of the visceral peritoneum of the diaphragmatic surface of the liver into the parietal peritoneum of the diaphragm. The posterior leaf of this ligament passes to the diaphragm from the visceral surface of the liver. Both leaves of the coronary ligament converge at their lateral ends and form the right and left triangular ligaments, lig. triangulare dextrum et lig. triangulare sinistrum.

The visceral peritoneum, peritoneum visceralis, of the liver covers the gallbladder on the lower side.

From the visceral peritoneum of the liver, the peritoneal ligament is directed to the lesser curvature of the stomach and the upper part of the duodenum. It is a duplication of the peritoneal layer, starting from the edges of the gate (transverse groove) and from the edges of the fissure of the venous ligament, and is located in the frontal plane. The left part of this ligament (from the fissure of the venous ligament) goes to the lesser curvature of the stomach - this is the hepatogastric ligament, lig, hepatogastricum. It looks like a thin web-like plate. Between the leaves of the hepatogastric ligament, along the lesser curvature of the stomach, pass the arteries and veins of the stomach, a. et v. gastricae, nerves; regional lymph nodes are located here. The right part of the ligament, more dense, goes from the porta hepatis to the upper edge of the pylorus and duodenum; this section is called the hepatoduodenal ligament, lig. hepatoduodenale, and includes the common bile duct, the common hepatic artery and its branches, portal vein, lymphatic vessels, nodes and nerves. On the right, the hepatoduodenal ligament forms the anterior edge of the omental foramen, foramen epiploicum (omentale). Approaching the edge of the stomach and duodenum, the leaves of the ligament diverge and cover the anterior and posterior walls of these organs.

Both ligaments: hepatogastric and hepatoduodenal - make up the lesser omentum, omentum minus. The non-permanent continuation of the lesser omentum is the hepatocolic ligament, lig. hepatocolicum, connecting the gallbladder with the right flexure of the colon. The falciform ligament and lesser omentum represent ontogenetically the anterior, ventral, mesentery of the stomach.

The parietal peritoneum extends from the left part of the dome of the diaphragm, passing onto the cardiac notch and the right half of the gastric vault, forming a small gastrophrenic ligament, lig. gastrophrenicum.

Between the lower edge of the right lobe of the liver and the adjacent upper end of the right kidney, the peritoneum forms a transitional fold - the hepatorenal ligament, lig. hepatorenal.

Leaves of the visceral peritoneum of the anterior and back surfaces The stomach along the greater curvature continues downward in the form of a greater omentum. The greater omentum, omentum majus, in the form of a wide plate (“apron”) follows down to the level of the upper aperture of the small pelvis. Here the two leaves that form it turn up and return, heading upward behind the descending two leaves. These return leaves are fused with the front leaves. At the level of the transverse colon, all four leaves of the greater omentum adhere to the omental band located on the anterior surface of the intestine. Then the posterior (recurrent) layers of the omentum extend from the anterior ones, connect to the mesentery of the transverse colon, mesocolon transversum, and go together dorsally to the line of attachment of the mesentery along the posterior abdominal wall in the region of the anterior edge of the body of the pancreas.

Thus, a pocket is formed between the anterior and posterior layers of the omentum at the level of the transverse colon. Approaching the anterior edge of the body of the pancreas, the two posterior layers of the omentum diverge: the upper layer passes into the posterior wall of the omental bursa (on the surface of the pancreas) in the form of a parietal layer of the peritoneum, the lower layer passes into the upper layer of the mesentery of the transverse colon.

The section of the greater omentum between the greater curvature of the stomach and the transverse colon is called the gastrocolic ligament, lig. gastrocolicum; this ligament fixes the transverse colon to the greater curvature of the stomach. Between the layers of the gastrocolic ligament along the greater curvature, the right and left gastroepiploic arteries and veins pass, and regional lymph nodes lie.

The greater omentum covers the front of the large and small intestine. A narrow gap is formed between the omentum and the anterior abdominal wall - the preomental space. The greater omentum is the distended dorsal mesentery of the stomach. Its continuation to the left is the gastrosplenic ligament, lig. gastrolienale, and diaphragmatic-splenic ligament, lig. phrenicolienale, which transform into one another.

Of the two layers of the peritoneum of the gastrosplenic ligament, the anterior one passes to the spleen, surrounds it on all sides, and returns back to the gate of the organ in the form of a leaf of the diaphragmatic-splenic ligament. The posterior leaf of the gastrosplenic ligament, having reached the hilum of the spleen, turns directly to the posterior abdominal wall in the form of a second leaf of the diaphragmatic-splenic ligament. As a result, the spleen is, as it were, included laterally in the ligament connecting the greater curvature of the stomach with the diaphragm.

The mesentery of the colon, mesocolon, varies in size in different parts of the colon and is sometimes absent. Thus, the cecum, which has the shape of a bag, is covered with peritoneum on all sides, but it does not have a mesentery. In this case, the vermiform appendix extending from the cecum, also surrounded on all sides by the peritoneum (intraperitoneal position), has a mesentery of the vermiform appendix, mesoappendix, reaching significant sizes. At the junction of the cecum with the ascending colon there is sometimes a small mesentery of the ascending colon, mesocolon ascendens.

Thus, the serous membrane covers the ascending colon on three sides, leaving the posterior wall free (mesoperitoneal position).

The mesentery of the transverse colon begins on the posterior abdominal wall at the level of the descending part of the duodenum, the head and body of the pancreas, and the left kidney; approaching the intestine at the mesenteric ribbon, two layers of the mesentery diverge and surround the intestine in a circle (intraperitoneal). Throughout the entire length of the mesentery from the root to the place of attachment to the intestine, its greatest width is 10-15 cm and decreases towards the bends, where it passes into the parietal layer.

The descending colon, like the ascending colon, is covered with a serous membrane on three sides (mesoperitoneal), and only in the area of the transition to the sigmoid colon is sometimes formed a short mesentery of the descending colon, mesocolon descendens. Only a small portion of the posterior wall of the middle third of the descending colon is not covered by peritoneum.

The mesentery of the sigmoid colon, mesocolon sigmoideum, has a width of 12-14 cm, which varies significantly throughout the colon. The root of the mesentery crosses the bottom of the iliac fossa obliquely to the left and from top to bottom and to the right, the iliacus and psoas muscles, as well as the left common iliac vessels and the left ureter located along the border line; Having rounded the border line, the mesentery crosses the area of the left sacroiliac joint and passes to the anterior surface of the upper sacral vertebrae. At the level of the third sacral vertebra, the mesentery of the sigmoid colon ends at the beginning of the very short mesentery of the rectum. The length of the mesenteric root varies greatly; the steepness and size of the loop of the sigmoid colon depend on it.

The relationship of the rectum to the pelvic peritoneum at its various levels changes. The pelvic part is more or less covered with a serous membrane. The perineal part is devoid of peritoneal cover. The uppermost (supra-ampullary) part, starting at the level of the third sacral vertebra, is completely surrounded by serous tissue and has a short and narrow mesentery.

The left flexure of the colon is connected to the diaphragm by a horizontally located peritoneal phrenic-colic fold (sometimes referred to as the diaphragmatic-colic ligament, lig. phrenicocolicum).

For a more convenient study of the topography of the peritoneum and organs of the abdominal cavity, a number of topographic-anatomical definitions are used that are used in the clinic and do not have either Latin terms or their Russian equivalents.

Peritoneal folds, ligaments, mesenteries and organs create depressions, pouches, bags and sinuses that are relatively isolated from each other in the peritoneal cavity.

Based on this, the peritoneal cavity can be divided into an upper floor and a lower floor.

The upper floor is separated from the lower floor by the horizontally located mesentery of the transverse colon (at the level of the II lumbar vertebra). The mesentery is the lower boundary of the upper floor, the diaphragm is the upper, and the lateral walls of the abdominal cavity limit it on the sides.

The lower floor of the peritoneal cavity is bounded above by the transverse colon and its mesentery, on the sides by the side walls of the abdominal cavity, and below by the peritoneum covering the pelvic organs.

In the upper floor of the peritoneal cavity, there are subphrenic recesses, recessus subphrenici, subhepatic recesses, recessus subhepatici, and omental bursa, bursa omentalis.

The subdiaphragmatic recess is divided into right and left parts by the falciform ligament. The right part of the subphrenic recess is a gap in the peritoneal cavity between the diaphragmatic surface of the right lobe of the liver and the diaphragm. It's limited at the back right side coronary ligament and right triangular ligament of the liver, on the left - falciform ligament of the liver. This depression communicates with the lower right subhepatic space, the right paracolic sulcus, then with the iliac fossa and through it with the small pelvis. The space under the left dome of the diaphragm between the left lobe of the liver (diaphragmatic surface) and the diaphragm is the left subphrenic recess.

On the right it is limited by the falciform ligament, on the back by the left part of the coronary and left triangular ligaments. This recess communicates with the lower left subhepatic recess.

The space under the visceral surface of the liver can be conditionally divided into two sections - right and left, the boundary between which can be considered the falciform and round ligaments of the liver. The right subhepatic recess is located between the visceral surface of the right lobe of the liver and the transverse colon and its mesentery. At the back, this depression is limited by the parietal peritoneum (hepatorenal ligament, lig. hepatorenale). Laterally, the right subhepatic recess communicates with the right paracolic sulcus, and in depth, through the omental foramen, with the omental bursa. The section of the subhepatic space, located deep at the posterior edge of the liver, to the right of the spinal column, is called the hepatorenal recess, recessus hepatorenalis.

The left subhepatic recess is a gap between the lesser omentum and the stomach on one side and the visceral surface of the left lobe of the liver on the other. Part of this space, located outward and somewhat posterior to the greater curvature of the stomach, reaches the lower edge of the spleen.

Thus, the right subphrenic and right subhepatic recesses surround the right lobe of the liver and the gallbladder (the outer surface of the duodenum faces here). In topographic anatomy they are combined under the name “hepatic bursa”. In the left subphrenic and left subhepatic recess there are left lobe liver, lesser omentum, anterior surface of the stomach. In topographic anatomy, this section is called the pregastric bursa. The omental bursa, bursa omentalis, is located behind the stomach. To the right it extends to the omental foramen, to the left - to the hilum of the spleen. The anterior wall of the omental bursa is the lesser omentum, the posterior wall of the stomach, the gastrocolic ligament, and sometimes the upper part of the greater omentum, if the descending and ascending leaves of the greater omentum are not fused and there is a gap between them, which is considered as a downward continuation of the omental bursa.

The posterior wall of the omental bursa is the parietal peritoneum, covering the organs located on the posterior wall of the abdominal cavity: the inferior vena cava, abdominal aorta, left adrenal gland, upper end of the left kidney, splenic vessels and below - the body of the pancreas, which occupies the largest space of the posterior wall of the omental bursa.

The upper wall of the omental bursa is the caudate lobe of the liver, the lower wall is the transverse colon and its mesentery. The left wall is the gastrosplenic and diaphragmatic-splenic ligaments. The entrance to the bag is the omental opening, foramen epiploicum (omentale), located on the right side of the bag behind the hepatoduodenal ligament. This hole allows 1-2 fingers through. Its anterior wall is the hepatoduodenal ligament with the vessels located in it and the common bile duct. The posterior wall is the hepatorenal ligament, behind which are the lower vena cava and the upper end of the right kidney. The lower wall is formed by the peritoneum, which passes from the kidney to the duodenum, and the upper wall is formed by the caudate lobe of the liver. The narrow section of the bursa closest to the opening is called the vestibule of the omental bursa, vestibulum bursae omentalis; it is bounded by the caudate lobe of the liver above and the upper part of the duodenum below.

Behind the caudate lobe of the liver, between it and the medial leg of the diaphragm, covered with parietal peritoneum, there is a pocket - the superior omental recess, recessus superior omentalis, which is open at the bottom towards the vestibule. Down from the vestibule, between the posterior wall of the stomach and the gastrocolic ligament in front and the pancreas covered with the parietal peritoneum and the mesentery of the transverse colon at the back there is a lower omental recess, recessus inferior omentalis. To the left of the vestibule, the cavity of the omental bursa is narrowed by the gastropancreatic fold of the peritoneum, plica gastropancreatica, running from the upper edge of the omental tubercle of the pancreas upward and to the left, to the lesser curvature of the stomach (it contains the left gastric artery, a. gastrica sinistra). The continuation of the lower recess to the left is the sinus, located between the gastrosplenic ligament (in front) and the phrenic-splenic ligament (back), which is called the splenic recess, recessus lienalis.

In the lower floor of the peritoneal cavity, on its posterior wall, there are two large mesenteric sinuses and two paracolic grooves. Here, the lower layer of the mesentery of the transverse colon, down from the root, passes into the parietal layer of the peritoneum, lining the posterior wall of the mesenteric sinuses.

The peritoneum, covering the posterior wall of the abdomen in the lower floor, passing on to the small intestine, surrounds it on all sides (except for the duodenum) and forms the mesentery of the small intestine, mesenterium. The mesentery of the small intestine is a double layer of peritoneum. The root of the mesentery, radix mesenterii, goes obliquely from top to bottom from the level of the II lumbar vertebra on the left to the sacroiliac joint on the right (place of confluence ileum in the blind). The length of the root is 16-18 cm, the width of the mesentery is 15-17 cm, however, the latter increases in the parts of the small intestine most distant from the posterior wall of the abdomen. Along its course, the root of the mesentery crosses at the top the ascending part of the duodenum, then the abdominal aorta at the level of the IV lumbar vertebra, the inferior vena cava and the right ureter. Along the root of the mesentery there are, following from top left to bottom and to the right, the superior mesenteric vessels; The mesenteric vessels give off intestinal branches between the layers of the mesentery to the intestinal wall. In addition, between the layers of the mesentery there are lymphatic vessels, nerves, and regional lymph nodes. All this largely determines that the duplication plate of the mesentery of the small intestine becomes dense and thickened.

The mesentery of the small intestine divides the peritoneal cavity of the lower floor into two sections: the right and left mesenteric sinuses.

The right mesenteric sinus is bounded above by the mesentery of the transverse colon, on the right by the ascending colon, and on the left and below by the mesentery of the small intestine. Thus, the right mesenteric sinus has the shape of a triangle and is closed on all sides. Through the parietal peritoneum lining it, the lower end of the right kidney (to the right) is contoured and visible at the top under the mesentery of the colon; adjacent to it is the lower part of the duodenum and the lower part of the head of the pancreas, surrounded by it. Below in the right sinus the descending right ureter and the ileocolic artery and vein are visible.

Below, at the point where the ileum enters the cecum, an ileocecal fold, plica ileocecalis, is formed. It is located between the medial wall of the cecum, the anterior wall of the ileum and the parietal peritoneum, and also connects medial wall the cecum with the lower wall of the ileum at the top and the base of the appendix at the bottom. In front of the ileocecal angle there is a fold of the peritoneum - the vascular cecal fold, plica cecalis vascularis, in the thickness of which the anterior cecal artery passes. The fold extends from the anterior surface of the mesentery of the small intestine and approaches the anterior surface of the cecum. Between the upper edge of the appendix, the ileum and the wall of the medial portion of the bottom of the cecum there is the mesentery of the appendix, mesoappendix. Feeding vessels pass through the mesentery, a. et v. appendiculares, and regional lymph nodes and nerves are embedded. Between the lateral edge of the bottom of the cecum and the parietal peritoneum of the iliac fossa there are cecal folds, plicae cecales.

Under the ileocecal fold lie the pockets located above and below the ileum: the upper and lower ileocecal recesses, recessus ileocecalis superior, recessus ileocecalis inferior. Sometimes under the bottom of the cecum there is a retrocecal recess, recessus retrocecalis.

To the right of the ascending colon is the right paracolic groove. It is limited externally by the parietal peritoneum of the lateral wall of the abdomen, on the left by the ascending colon; communicates downward with the iliac fossa and the peritoneal cavity of the small pelvis. At the top, the groove communicates with the right subhepatic and subphrenic recesses. Along the groove, the parietal peritoneum forms transverse folds connecting the upper right bend of the colon with the lateral wall of the abdomen and the right diaphragmatic-colic ligament, usually weakly expressed, sometimes absent.

The left mesenteric sinus is bounded above by the mesentery of the transverse colon, on the left by the descending colon, and on the right by the mesentery of the small intestine. Inferiorly, the left mesenteric sinus communicates with the peritoneal cavity of the small pelvis. The sinus has an irregular quadrangular shape and is open downwards. Through the parietal peritoneum of the left mesenteric sinus, the lower half of the left kidney is transilluminated and contoured at the top, below and medially in front of the spine - the abdominal aorta and to the right - the inferior vena cava and the initial segments of the common veins. iliac vessels. To the left of the spine the left artery of the testicle (ovary), the left ureter and branches of the lower mesenteric artery and veins. In the upper medial corner, around the beginning of the jejunum, the parietal peritoneum forms a fold that borders the intestine from above and to the left - this is the superior duodenal fold (duodeno-jejunal fold), plica duodenalis superior (plica duodenojejunalis). To the left of it is the paraduodenal fold, plica paraduodenalis, which is a semilunar fold of the peritoneum located at the level of the ascending part of the duodenum and covering the left colon artery. This fold limits the front of the unstable paraduodenal recess, recessus paraduodenalis, the posterior wall of which is made up of the parietal peritoneum, and to the left and below runs the lower duodenal fold (duodenal-mesenteric fold), plica duodenalis inferior (plica duodenomesocolica), which is triangular shape a fold of the parietal peritoneum that passes into the ascending part of the duodenum.

To the left of the root of the mesentery of the small intestine, behind the ascending part of the duodenum, there is a peritoneal fossa - a retroduodenal recess, recessus retroduodenalis, the depth of which can vary. To the left of the descending colon is the left paracolic groove; it is limited on the left (laterally) by the parietal peritoneum lining the lateral wall of the abdomen. Downwards, the groove passes into the iliac fossa and then into the pelvic cavity. Upwards, at the level of the left flexure of the colon, the groove is crossed by a constant and well-defined phrenic-colic fold of the peritoneum.

Below, between the bends of the mesentery of the sigmoid colon, there is a peritoneal intersigmoid recess, recessus intersigmoideus.

You might be interested in this read:

Structure of the abdomen: abdominal organs and methods of examining the abdominal cavity

Knowledge of the structural features and location of the abdominal organs is important for understanding many pathological processes. The abdominal cavity contains the digestive and excretory organs. The structure of the abdomen must be described taking into account the relative position of these organs.

Abdomen - the space between the sternum and pelvis

The abdomen refers to the space of the body between the chest and pelvis. The basis of the internal structure of the abdomen is the abdominal cavity, which contains the digestive and excretory organs.

Anatomically, the area is limited by the diaphragm, located between the thoracic and abdominal cavities. The pelvic region begins at the level of the pelvic bones.

The structural features of the abdomen and abdominal cavity determine many pathological processes. The digestive organs are held together by special connective tissue, the mesentery.

This tissue has its own characteristics of blood supply. The abdominal cavity also contains organs of other important systems - the kidneys and spleen.

Many large blood vessels supply the tissues and organs of the abdominal cavity. In this anatomical region, the aorta and its branches, the inferior genital vein and other large arteries and veins are distinguished.

Organs and great vessels The abdominal cavity is protected by muscle layers that form external structure belly.

External structure and abdominal muscles

Structure of the abdomen: internal organs

The external structure of the abdomen is no different from the structure of other anatomical regions of the body. The most superficial layers include the skin and subcutaneous fat.

The subcutaneous fat layer of the abdomen can be developed to varying degrees in people with different constitutional types. The skin, fat and subcutaneous fascia contain a large number of arteries, veins and nerve structures.

The next layer of the abdomen contains muscles. The abdominal area has a fairly powerful muscle structure that allows it to protect the abdominal organs from external physical influence.

The abdominal wall consists of several paired muscles, the fibers of which are intertwined in different places. Main abdominal muscles:

External oblique muscle. This is the largest and most superficial paired abdominal muscle. It originates from the eight lower ribs. Fibers of the external oblique muscle participate in the formation of a dense aponeurosis of the abdomen and inguinal canal, containing the structures of the reproductive system.
Internal oblique muscle. This is the structure of the intermediate layer of paired abdominal muscles. The muscle originates from the iliac crest and part of the inguinal ligament. Individual fibers are also associated with the ribs and pubic bones. Like the external muscle, the internal oblique muscle is involved in the formation of the wide abdominal aponeurosis.
Transverse abdominis muscle. This is the deepest muscle of the superficial layer of the abdomen. Its fibers are connected to the ribs, iliac crest, inguinal ligament, fascia of the chest and pelvis. The structure also forms the aponeurosis and inguinal canal.
Rectus abdominis muscle. It is a long muscle associated with the ribs, sternum and pubic bone. It is this muscle layer that forms the so-called abdominal press, which is clearly visible in physically developed people. The functions of the rectus abdominis muscle are associated with flexion of the body, obstetric processes, defecation, urination and forced exhalation.
Pyramidal muscle. It is a triangular muscle structure located in front of the lower part of the rectus abdominis muscle. The fibers of the pyramidalis muscle are connected to the pubic bones and the linea alba. The muscle may be absent in 20% of people, which is due to individual characteristics abdominal structure.
The aponeuroses and muscle lines of the abdomen are of particular importance in protecting and maintaining the shape of the abdominal structures. In addition, the abdominal muscles form the inguinal canal, which contains the spermatic cord in men and the round ligament of the uterus in women.

Read: Colonoscopy of the intestines: all about the procedure

Abdominal structure: muscles

The internal structure of the abdomen is represented by the abdominal cavity. The cavity is lined from the inside by peritoneum, which has internal and external layers.

Between the layers of the peritoneum are the abdominal organs, blood vessels and nerve formations. In addition, the space between the layers of the peritoneum contains a special liquid that prevents friction.

The peritoneum not only nourishes and protects the structures of the abdomen, but also anchors the organs. The peritoneum also forms what is called mesenteric tissue, which is connected to the abdominal wall and abdominal organs.

The boundaries of the mesenteric tissue extend from the pancreas and small intestine to the lower parts of the colon. The mesentery secures organs in a certain position and nourishes tissues with the help of blood vessels.

Some abdominal organs are located directly in the abdominal cavity, others in the retroperitoneal space. Such features are determined by the position of the organs relative to the layers of the peritoneum.

Abdominal organs

The organs located in the abdominal cavity belong to the digestive, excretory, immune and hematopoietic systems.

Their mutual arrangement ensures the performance of many joint functions.

Main organs of the abdomen:

Liver. The organ is located in the right abdomen directly below the diaphragm. The functions of this organ are related to the processes of digestion, detoxification and metabolism. All nutritional components formed as a result of digestion enter the liver cells along with the blood, where chemical compounds harmful to the body are neutralized. The liver is also involved in the formation of bile, which is necessary for the digestion of fats.
Stomach. The organ is located in the left abdomen under the diaphragm. This is an extended part of the digestive tract, connected to the esophagus and the initial part of the small intestine. The key processes of chemical decomposition of food substrates occur in the stomach. In addition, stomach cells help absorb vitamin B12, which is necessary for the functioning of body cells. Hydrochloric acid contained in the stomach helps destroy bacteria.
Gallbladder. The organ is located under the liver. The gallbladder is a storage facility for bile. When food components enter the duodenum for digestion, the gallbladder secretes bile into the intestinal cavity.
Pancreas. This structure is located below the stomach between the spleen and duodenum. The pancreas is an indispensable digestive organ necessary for the final processes of food digestion. The gland produces enzymes that make it possible to convert large food components into the structural units necessary for cells. The role of the pancreas in glucose metabolism is also very important. The gland secretes insulin and glucagon, which control blood sugar.
Spleen. The organ is located in the left region of the abdomen next to the stomach and pancreas. It is an organ of hematopoiesis and immunity, allowing the deposition of blood components and the disposal of unnecessary cells.
Small and large intestines. The main processes of digestion and assimilation of food substrates occur in the sections of the small intestine. The large intestine produces and stores feces and also absorbs water.
Kidneys. These are paired excretory organs that filter the bloodstream and dispose of metabolic waste. The kidneys are connected to the ureters, bladder and urethra. In addition, the kidneys secrete a number of important substances necessary for the synthesis of vitamin D and the formation of red blood cells.

Read: Spleen: normal organ sizes

The close proximity of the abdominal organs determines the characteristics of many diseases. Inflammatory processes associated with the entry of bacteria into the abdominal cavity can be deadly.

Methods for examining abdominal organs

Intestines: human anatomy

Numerous diagnostic methods allow you to assess the condition of the abdominal organs and, if necessary, confirm the presence of the disease.

Doctors begin with a physical examination of the patient, which allows them to detect external manifestations of pathologies. The next stage of diagnosis is the appointment instrumental methods research.

Methods for examining the abdominal organs:

Esophagogastroduodenoscopy. A flexible tube equipped with a camera is inserted through the mouth into the patient's digestive tract. The device allows you to assess the condition of the esophagus, stomach and duodenum.
Colonoscopy. In this case, the tube is inserted into the lower digestive tract through the anus. The procedure allows you to examine the rectum and colon.
X-ray and computed tomography. The methods allow you to take pictures of the abdominal cavity.
Magnetic resonance imaging. This highly accurate method is often used for detailed examination of the liver, pancreas and gallbladder.
Ultrasound diagnostics. The procedure evaluates general state abdominal organs.

Specialized techniques, including biopsy and breath testing, may be used to diagnose specific diseases.

Thus, the structure of the abdomen is important not only from the point of view of anatomical features, but also from the point of view of diagnosing diseases.

The following video will introduce you to the anatomy of the human abdominal cavity:

Tell your friends! Tell your friends about this article in your favorite social network using social buttons. Thank you!

Source: http://PishheVarenie.com/organy-zhkt/stroenie-zhivota/

What is the human abdominal cavity?

You've probably heard this expression more than once: “human abdominal cavity”? But can you pinpoint exactly what it is?

Where does this cavity begin and where does it end? What is in this cavity and why is it called that. Although the latter is not difficult to guess.

Let's try to define this concept more clearly in this article. After all, medicine is, of course, not mathematics, but still a science. And accuracy and certainty will not interfere with her at all.

So, the abdominal cavity is one of the cavities of the human body

And there are a lot of cavities in the human body. From as large as the abdominal and thoracic cavities to as small as the oral or nasal cavity.

The entire human body is divided into two large cavities: the thoracic and abdominal. And the boundary between these cavities is the diaphragm. Above the diaphragm is the chest cavity. Below it is the abdominal cavity.

We have identified one of the boundaries of the abdominal cavity - the upper one. It is formed by the diaphragm.

The anterior and lateral walls of the abdominal cavity are nothing more than the muscles and tendons of the anterior and lateral walls of the abdomen. And the back is the spine and back muscles.

From below, the abdominal cavity is formed by the bones and muscles of the pelvis.

Peritoneum

The entire abdominal cavity is neatly and carefully lined with a special membrane - the peritoneum. The peritoneum has two layers.

Parietal peritoneum

One leaf lines the entire abdominal cavity from the inside, covering the walls of the abdominal cavity.

It is called the parietal peritoneum (from the Latin word parietis - wall).

Visceral peritoneum

The second leaf covers the organs located in the abdominal cavity. And this piece of peritoneum is called the visceral peritoneum (from the Latin word viscera - insides).

Retroperitoneal space

But the visceral peritoneum does not envelop all organs located in the abdominal cavity.

Some of the organs adjacent to the back are covered with visceral peritoneum on only one side. This space between the parietal peritoneum, which covers the posterior wall of the abdominal cavity, and the visceral peritoneum is called the retroperitoneal space.

Pelvic cavity

The organs located in the pelvic area are also covered by peritoneum on only one side. This makes it possible to identify another cavity in the abdominal cavity - the pelvic cavity.

That is, the peritoneum divides the abdominal cavity into three cavities:

peritoneal space (located anteriorly)
retroperitoneal space (located posteriorly)
pelvic cavity (located below)

The abdominal cavity contains organs covered by peritoneum on all sides, three sides and only one side.

Between the two layers of peritoneum there is the so-called peritoneal space. In this space, in addition to the organs, there is a small amount of serous fluid.

What organs are located in the abdominal cavity?

Here is their list:

In the retroperitoneal space are located:

In the peritoneal cavity are located:

In the pelvic cavity are located:

bladder
rectum
in women - the uterus with its appendages and vagina, in men - the prostate gland and seminal vesicles

The descending and ascending colon are partially covered by peritoneum (located mesoperitoneally).

The liver is covered almost completely by peritoneum.

Sections of the abdominal cavity

For ease of designation and orientation, the human stomach or anterior abdominal wall is divided into three floors.

Each of these floors is divided into three more parts. The result is a picture like this.

On the top floor there are:

three areas from right to left:

right hypochondrium
epigastrium
left hypochondrium

On the middle floor there are:

>right lateral region
mesogastrium
left lateral region

And on the lower floor there are:

right iliac region
hypogastrium
left iliac region

Having at your disposal such a “map” of the anterior abdominal wall, you can easily and accurately identify the area where this or that organ is located, isn’t it?

Want to know more about the abdominal cavity? Information here!

And now some brief conclusions:

The abdominal cavity is one of the large cavities of the human body.
The abdominal cavity serves as a container for a number of organs
It is formed from above - by the diaphragm, in front and from the sides - by the front and side walls of the abdomen, from below - by the bones and muscles of the pelvis, from behind - by the spine and back muscles

Now, knowing and understanding what the human abdominal cavity is, how and how it is formed, it will be easier and simpler for us to talk about the organs located in it.

Previous article – What kind of spleen does a person have?

Next article – What does the spleen do?

Source: https://uziforyou.info/html/bryushnayapolost.html

How does the human abdominal cavity work?

The human abdominal cavity has a special structure that significantly distinguishes us from other mammals. What is the abdominal cavity? This term denotes a part of space in human body, which is separated from the chest by the diaphragm at the top and contains the internal organs of the peritoneum. Most of these are organs of the digestive and genitourinary systems.

Abdominal organs in the diagram

The topography of the abdominal cavity is as follows:

The abdominal muscles (three broad and rectus) act as its front wall.
The side walls are formed by some of the vastus abdominis muscles.
Rear space is limited lumbar region spine with adjacent muscle fibers.
The lower part of this anatomical structure borders the pelvic region.
The upper floor of the abdominal cavity is “covered” by the muscles of the diaphragm.

What is the structure of the abdominal cavity

The peritoneum is a thin structure consisting of connective tissue, a large number of strong fibers and an epithelial layer - mesothelium. It lines the inner wall of the structure.

The mesothelium performs an important function - its cells synthesize serous secretion, which serves as a lubricant for the outer walls of all internal organs located in the stomach.

Since the organs and glands are quite close to each other, the mesothelial secretion reduces the area of their friction.

This unique structure of the abdominal cavity in humans normally contributes to the absence of discomfort with minor changes in the abdominal area.

But if a focus of inflammation occurs in this area when an infectious agent gets inside, the person feels a sharp pain syndrome. At the first signs of inflammation, numerous adhesions form in the peritoneal space, which prevent the infectious process from spreading to the entire abdominal area.

The peritoneal space is usually divided into the peritoneum itself and the retroperitoneal zone.

The organs of the abdominal cavity develop in the space between its wall and the peritoneum. As they grow, they move away from the posterior wall, merging with the peritoneum and stretching it.

This leads to the formation of a new structural unit - the serous fold, which consists of 2 leaves.

Such abdominal folds, originating from the inner walls of the abdomen, reach the intestines or other organs of the human abdominal cavity. The former are called mesenteries, the latter ligaments.

Topographic anatomy

The upper floor of the abdominal section contains elements of the digestive tract. Conventionally, we can divide the abdominal zone of the body into a pair of vertical and a pair of horizontal lines that will delimit the sections of the peritoneum. Topographic anatomy The abdominal cavity is conventionally divided into 9 zones.

The location of the abdominal organs in its upper part (another name is the omental foramen) is as follows: in the right hypochondrium there is a liver with a gallbladder, in the epigastric (middle) zone there is a stomach, in the left hypochondrium there is a spleen.

The middle row is conventionally divided into 4 regions of the abdominal cavity: right lateral, mesogastric (umbilical), umbilical and left lateral. The following internal organs are located in these zones: small intestine, ascending and descending colons, kidneys, pancreas and some others.

In the bottom row, the right and left iliac regions are distinguished, between which the hypogastric zone is located. They contain part of the colon and cecum, the bladder, and in women, the uterus and ovaries.

Depending on the degree of peritoneal coverage, the organs that enter the abdominal cavity can be located intraperitoneally, mesoperitoneally or extraperitoneally. The intraperitoneal position indicates that this internal organ is surrounded by the peritoneum on all sides.

An example of such an arrangement is the small intestine. In the mesoperitoneal position, the organ is surrounded by peritoneum on only 3 sides, as is the case with the liver. The extraperitoneal position of the organ implies that it is covered by the peritoneum only on the anterior side.

The kidneys have this arrangement.

Anatomical differences between the male and female peritoneum

The structure of the abdominal cavity is identical in all people. The exceptions are congenital developmental anomalies, transposition (mirror arrangement) of internal organs. But this case is very rare.

Due to the biological ability to bear and give birth to children in female body The structure of the abdominal organs is arranged somewhat differently than in men.

The abdominal space in men is closed in the lower part, while in women the fallopian tubes communicate with the uterine region. Through the vagina, the peritoneum in women is indirectly connected with the environment.

In a man, the reproductive system is located outside, therefore there is no connection with the peritoneal area.

Serous fluid in the abdomen in men immediately covers 2 walls of the rectum - the anterior and posterior. The peritoneal membrane also envelops the upper part of the bladder and the anterior wall of the cavity. As a result of these anatomical features, a man's body has a small depression between the bladder and the rectum.

In the female body, the serous layer of the peritoneum partially covers the rectum, and then the outer surface of the uterus and part of the vagina. This forms a depression between the rectum and the uterus, which is limited by folds on both sides.

There are also certain age-related differences in the structure of the peritoneum and the location of human internal organs in it. For example, in young children the thickness of the abdominal layer is much less than in adults.

The reason for this is the poor development of the layer of subperitoneal fatty tissue, which is typical for infants. In newborn children, the omentum is short and thin, with pits and folds almost invisible.

With age, these formations increase and deepen.

Source: http://prozhkt.ru/anatomiya/bryushnaya-polost.html

What is included in an abdominal ultrasound?

Ultrasound of the abdominal cavity is not too complicated, but quite an effective procedure, which gives doctors a unique opportunity to assess the condition of internal organs, as well as establish their size and other important criteria for treatment.

The perfect safety of research based on the use of ultrasound allows its use in any area of modern medicine. After all, this is how you can simply and most accurately detect even the most insignificant change in the body.

In order to do everything correctly, it is worth finding out everything about ultrasound of the abdominal cavity in advance: what is included in this examination, what is the preparation. It is equally important to find out what kind of diet should be followed before an ultrasound scan of the abdominal cavity, so that the results most accurately reflect the state of the body.

Which organs are examined by abdominal ultrasound?

So, the patient is prescribed an ultrasound of the abdominal cavity. What is included in this concept and is subject to examination? When we talk about this area, we mean the space in the abdomen, which includes a number of organs.

It is closed from above by a diaphragm; the muscles of the back, tissue and spine limit it from behind; the abdominal muscles stabilize in front, and skeletal system and the pelvic musculature is supported from below. The inner surface of the abdominal cavity is covered with a thin layer of tissue with a mass of nerve endings, called the peritoneum. One part of it is called visceral, the other is called perietal.

When understanding which organs are included here, you need to remember that they are all divided into four groups.

1. In the abdominal region itself there are a completely membrane-covered liver, pancreas, gall bladder, as well as a spleen and part of the stomach.

2. In addition, the abdominal cavity contains organs that are only partially covered by peritoneum. Finding out everything about an ultrasound of the abdominal organs, finding out what is included in it, the patient learns that it is the intestine (both large and, of course, small), the pancreas, and also the duodenum.

3. The organs of the retroperitoneal space will certainly be included in an examination such as an ultrasound of the abdominal cavity. What does it include? These are the kidneys with the adrenal glands, the aorta with its branches, the ureters, the inferior vena cava with all its tributaries.

4. The bladder is examined from the preperitoneal space.

Abdominal organs

It must be said that not all of these organs are visible on ultrasound, so not all are examined.

Preparing for the examination

When understanding what a procedure such as an ultrasound of the abdominal organs includes, you must not forget that this examination requires some preparation, for example, a special diet is required. Before you go to medical institution It’s worth adjusting your diet and other aspects, finding out what you can eat and whether you can drink, for example, water, and how to eat properly.

So, what is needed for an abdominal ultrasound to be as informative as possible?

Preparing for an abdominal ultrasound

You will have to prepare three days before the appointed date in order to put your body in order and avoid increased gas formation or even bloating, that is, you cannot drink or eat anything that can lead to such results.
All legumes, all flour, sweets, as well as bread are thrown out of the daily diet. Raw vegetables and raw fruits that contain fiber are not allowed.
When learning what is included in the ultrasound procedure when it comes to the abdominal organs, a person learns that it is impossible to eat sauerkraut, drink milk, or drink carbonated drinks before the ultrasound.
Under no circumstances should you drink alcohol or take any drugs.
Oddly enough, you should also refrain from chewing gum before the procedure; the diet before the ultrasound should not contain it.
So, what to do before such a study as an ultrasound? It's best to set it up the day before. special diet, which certainly includes lean fish, lean meat, ideally cooked in a double boiler, you need to eat baked apples, grain porridge (cooked without adding milk).
You need to eat fractionally, in small portions, to prevent overeating.
You can eat your last meal six hours before your scheduled ultrasound. The examination itself is carried out exclusively on an empty stomach.
During all the preparation before an ultrasound of the abdominal cavity, it is not only possible, but also necessary to drink water: a sufficient amount (at least one and a half liters), and for the most part it should be clean water. In principle, you are allowed to drink unsweetened tea.
What should and can be done before an abdominal ultrasound procedure if it is prescribed for a child, a pregnant woman or a person with diabetes? The preparation will have some features and be much more gentle.
Small children and infants can eat on the day of the examination, but the last meal should end three hours before the appointed time. If less time passes, the doctor simply will not be able to fully examine the gallbladder and pancreas. For older children, the break between meals before the procedure can be extended to four hours, and they can also be allowed to drink.
Patients with diabetes mellitus People often ask what they can eat the day before if an abdominal ultrasound is scheduled. They can safely eat a couple of crackers and drink tea with a small amount of sugar right before the examination.
A pregnant woman should not eat anything on the eve of the scheduled ultrasound, at least a couple of hours before. In this case, it is best to schedule the procedure in the morning to make the hunger strike easier to bear.
As for medications, it would be correct to remember: taking any medications before an ultrasound is possible only after consultation with the treating specialist. You can’t do anything at your own risk, you need to undergo a consultation. The doctor, based on the characteristics of each patient’s body, can prescribe medications to prevent flatulence or improve digestive functions in general.
Based on which organs doctors look at in each individual patient on an abdominal ultrasound, these may be both enzymes and various enterosorbents. If there is a suspicion of disturbances in the functioning of the gastrointestinal tract, it is better for the patient to take measures in advance to cleanse the intestines, to do everything correctly, because it is very important that this organ is empty before the ultrasound.

In such cases, the doctor may prescribe a laxative or special suppositories. In some cases, even cleansing enemas are recommended.

If your kidney condition is to be examined, your bladder should be full, so you will have to drink at least a liter of water or weak tea.

Many people wonder whether it is possible to smoke before an examination such as an abdominal ultrasound. The answer here is negative: of course, you should abstain and not smoke during the entire preparation.

When is the examination scheduled?

Having learned which organs doctors look at during an abdominal ultrasound, it is also worth finding out that this examination is necessarily prescribed by a specialist in the following cases:

When the patient complains of pain in the abdominal area, pulsation.

If appendicitis is suspected, especially in cases involving children.

If the patient speaks of a feeling of heaviness under the right rib, the appearance of bitterness in the mouth, complains of bitter belching and a yellow coating on the tongue.

If a person suddenly begins to feel an aversion to fatty foods without taking any medications.

To monitor the condition of patients with liver diseases (for example, hepatosis or hepatitis), various types of jaundice, with stones and sand, for example, in the gall bladder.

Ultrasound is also necessary for patients with an increase in the size of the liver and spleen due to such ailments as malaria, mononucleosis, sepsis, anemia and a number of others.

If a person talks about difficulty or painful urination and changes in the color and amount of urine, especially in cases where the amount of liquid in the diet itself has not changed.

When learning about abdominal ultrasound and what organs it can examine, it is worth remembering that the procedure can also be prescribed for pain in the lumbar region, after injuries to the lower back or the abdomen itself (what is included there will be determined by the doctor, especially if a person begins to lose weight , suffer from decreased appetite, lethargy, weakness).

If the patient is undergoing surgery on any of the abdominal organs or kidneys.

Together with a biopsy of the liver, kidneys, and removal of fluid from the abdominal cavity.

Having found out what an examination such as an abdominal ultrasound includes, the patient must understand one important thing: if he does not follow the recommendations given to him by the doctor, the effectiveness of the examination is called into question.

The presence of gases in the intestines, bloating, an empty bladder, too little time that has passed since the last meal directly affect the data that will be obtained during an ultrasound. That is why it is so important to comply with all the requirements of the radiologist.

What can be revealed during the examination

So, what will be visible on the doctor’s screen during an abdominal ultrasound? During the procedure, the following diseases can be identified:

If the subject of study is the liver, then ultrasound can reveal hepatosis, calcifications, cysts and chronic hepatitis, various tumors of both benign and malignant nature, injuries, the appearance of metastases, increased pressure in the portal vein, and abscess.

Hepatosis on ultrasound

In the case when the gallbladder and ducts are examined, the doctor can determine the development of cholecystitis, assess patency, and see stones and polyps.

Gallstones

Examination of the pancreas is more difficult than other types of ultrasound, since this organ is partially covered not only by the stomach, but also by the intestines. During the examination, it is possible to determine even the early stages of pancreatitis or pancreatic necrosis of the organ.

Pancreatitis on ultrasound

Conducting an ultrasound of the spleen is also quite difficult, since this organ is covered not only by the ribs, but also by the lungs, filled with air. Increases in size, shape and any other changes in the organ indicate serious problems: leukemic infiltration, abscesses, hematomas, ruptures or heart attacks.

Splenic hematoma

If the stomach is examined, diseases such as gastroesophageal reflux, hernia, and various cysts can be identified. In children, pyloric stenosis may be detected (accompanied by thickening of the pyloric ring).

Examination of the intestines is not mandatory during a standard abdominal ultrasound and is carried out only in the case of special purpose doctor

To know how to properly perform such a narrow examination from the area of abdominal ultrasound, you should consult a doctor for recommendations.

The procedure can reveal the presence of fluid in the abdominal cavity, tumor formations in the intestine itself, abscesses, hematomas, cysts, enlargement lymph nodes, ischemia.

Ultrasound of the abdominal cavity and especially the kidneys can detect not only stones, but also changes associated with inflammation, as well as various tumors. There is no need for a special diet before the procedure; it is important to follow the general requirements.

Examination of the bladder allows you to assess the general condition of the organ, identify stones, any foreign bodies, prolapse of the ureters, various tumors, as well as diverculosis of the bladder walls.

Prolapse of the ureters on ultrasound

If an ultrasound scan of the uterus or prostate gland is performed, then inflammatory processes, presence of tumors.

Lymph nodes must also be examined. If they are enlarged, it means that the body is developing serious disease or cancerous tumor.

In the area of the porta hepatis, paracaval and in the area of the porta spleen there are lymph nodes. Swelling of the paravesical tissue around the gallbladder is pronounced.

Patient actions after abdominal ultrasound

After a qualified doctor conducts the examination, the patient receives a card with a detailed description of the results of the procedure. This usually takes a few minutes. The patient can discuss his condition with him or go to his specialist doctor.

If the specialist is alerted to any deviations from the norm (any inflammation, damage or displacement of organs), he will send the patient for additional examinations of a more specialized, narrow nature. The same thing happens when ultrasound reveals cysts, tumors, fluid or stones.

Conclusion

Thus, ultrasound remains one of the most popular and frequently used methods for diagnosing and examining patients with various complaints and diseases.

The peritoneum (peritoneum) covers the walls of the abdominal cavity and internal organs; its total surface is about 2 m2. In general, the peritoneum consists of parietal (peritoneum parietale) and visceral (peritoneum viscerale). The parietal peritoneum lines the abdominal walls, the visceral peritoneum lines the insides (Fig. 275). Both leaves, touching each other, seem to slide one against the other. This is facilitated by the muscles of the abdominal walls and positive pressure in the intestinal tube. The gap between the leaves contains a thin layer of serous fluid, which moisturizes the surface of the peritoneum, facilitating the displacement of internal organs. When the parietal peritoneum transitions into the visceral peritoneum, mesenteries, ligaments and folds are formed.

Under the peritoneum, almost everywhere lies a layer of subperitoneal tissue (tela subserosa), consisting of loose and adipose tissue. The thickness of the subperitoneal tissue in different parts of the abdominal cavity is expressed to varying degrees. There is a significant layer of it on the anterior abdominal wall, but the fiber is especially well developed around the bladder and below the umbilical fossa. This is due to the fact that when the bladder is stretched, its apex and body come out from behind the symphysis, penetrating between the f. transversalis and parietal peritoneum. The subperitoneal tissue of the small pelvis and posterior abdominal wall is represented by a thick layer, but this layer is absent on the diaphragm. Subperitoneal tissue is well developed in the mesentery and peritoneal omentum. The visceral peritoneum is most often fused with organs and subperitoneal tissue is completely absent (liver, small intestine) or moderately developed (stomach, large intestine, etc.).

The peritoneum forms a closed sac, so some of the organs lie outside the peritoneum and are covered by it only on one side.

275. Location of the visceral (green line) and parietal (red line) layers of the peritoneum on a sagittal section of a woman.
1 - pulmo: 2 - phrenicus; 3 - lig. coronarium hepatis; 4 - recessus superior omentalis; 5 - lig. hepatogastricum; 6 - for. epiploicum; 7 - pancreas; 8 - radix mesenterii; 9-duadenum; 10 - jejunum; 11 - colon sigmoideum; 12 - corpus uteri; 13 - rectum; 14 - excavatio rectouterina; 15 - anus; 16 - vagina; 17 - urethra; 18 - vesica urinaria; 19 - excavatio vesicouterina; 20 - peritoneum parietalis; 21 - omentum majus; 22 - colon transversum; 23 - mesocolon; 24 - bursa omentalis; 25 - ventriculus; 26 - hepar.

This position of the organs is called extraperitoneal. The extraperitoneal position is occupied by the duodenum, with the exception of its initial part, the pancreas, kidneys, ureters, prostate gland, vagina, and lower rectum. If the organ is covered on three sides, it is called the mesoperitoneal position. These organs include the liver, the ascending and descending parts of the colon, the middle part of the rectum, and the bladder. Some organs are covered with peritoneum on all sides, i.e. they lie intraperitoneally. The stomach, jejunum and ileum, appendix, cecum, transverse colon, sigmoid and beginning of the rectum, uterus and fallopian tubes, and spleen have this position.

The topography of the parietal and visceral peritoneum is clearly visible on the sagittal section of the torso. Conventionally, a single peritoneal cavity is divided into three floors: upper, middle and lower (Fig. 276).

276. Topography of the peritoneum of the upper, middle and lower floors of the peritoneal cavity.
1 - lobus hepatis sinister; 2 - ventriculus; 3 - pancreas; 4 - lien; 5 - bursa omentalis; 6 - mesocolon transversum; 7 - flexura duodenojejunalis; 8 - colon transversum; 9 - ren sinister; 10 - radix mesenteric 11 - aorta; 12 - colon descendens; 13 - mesocolon sigmoideum; 14 - colon sigmoideum; 15 - vesica urinaria; 16 - rectum; 17 - appendix vermiformis; 18 - cecum; 19 - colon ascendens; 20 - duodenum; 21 - flexura coli dextra; 22 - pylorus; 23 - for. epiploicum; 24 - lig. hepatoduodenal; 25 - lig. hepatogastricum.

The upper floor is bounded above by the diaphragm and below by the mesentery of the transverse colon. It contains the liver, stomach, spleen, duodenum, and pancreas. The parietal peritoneum continues from the anterior and posterior walls to the diaphragm, from where it passes to the liver in the form of ligaments - ligg. coronarium hepatis, falciforme hepatis, triangulare dextrum et sinistrum (see Ligaments of the liver). The liver, with the exception of its posterior edge, is covered with visceral peritoneum; its posterior and anterior leaves meet at the gate of the liver, where the ductus choledochus, v. portae, a. hepatica propria. A double layer of peritoneum connects the liver with the kidney, stomach and duodenum in the form of ligaments - ligg. phrenicogastricum, hepatogastricum, hepatoduodenale, hepatorenale. The first three ligaments form the lesser omentum (omentum minus). The leaves of the peritoneum of the lesser omentum in the area of the lesser curvature of the stomach diverge, covering its anterior and posterior walls. On the greater curvature of the stomach, they again unite into a two-layer plate, hanging freely in the abdominal cavity in the form of a fold at a distance of 20-25 cm from the greater curvature in an adult. This two-layer plate of the peritoneum turns upward and reaches the posterior abdominal wall, where it grows at the level of the II lumbar vertebra.

The four-layer fold of peritoneum hanging in front of the small intestine is called the greater omentum (omentum majus). In children, the layers of the peritoneum of the greater omentum are well defined.

The two-layer peritoneum at the level of the II lumbar vertebra diverges in two directions: one layer lines the posterior abdominal wall above the II lumbar vertebra, covering the pancreas and part of the duodenum, and represents the parietal layer of the omental bursa. The second layer of peritoneum from the posterior abdominal wall descends down to the transverse colon, surrounding it on all sides, and again returns to the posterior abdominal wall at the level of the II lumbar vertebra. As a result of the fusion of 4 layers of the peritoneum (two - the greater omentum and two - the transverse colon), the mesentery of the transverse colon (mesocolon) is formed, which constitutes the lower border of the upper floor of the peritoneal cavity.

In the upper floor of the peritoneal cavity between the organs there are limited spaces and bags. The right subphrenic space is called the hepatic bursa (bursa hepatica dextra) and represents a narrow gap between right lobe liver and diaphragm. Below, it communicates with the right lateral canal, which is formed by the ascending colon and the abdominal wall. At the top, the bursa is bounded by the coronoid and falciform ligaments.

The left subdiaphragmatic bursa (bursa hepatica sinistra) is smaller than the right one.

The omental bursa (bursa omentalis) is a large cavity containing 3-4 liters and is largely isolated from the peritoneal cavity. The bursa is bounded in front by the lesser omentum and stomach, gastrocolic ligament, below by the mesentery of the transverse colon, behind by the parietal peritoneum, above by the phrenic-gastric ligament. The omental bursa communicates with the peritoneal cavity by the omental foramen (for. epiploicum), limited anteriorly by lig. hepatoduodenale, above - liver, behind - lig. hepatorenale, below - lig. duodenorenale.

The middle floor of the peritoneal cavity is located between the mesentery of the transverse colon and the entrance to the pelvis. It houses the small intestine and part of the large intestine.

Below the mesentery of the transverse colon, a layer of peritoneum from the small intestine passes to the posterior abdominal wall and suspends the loops of the jejunum and ileum, forming the mesenterium. The root of the mesentery has a length of 18-22 cm, attaching to the posterior abdominal wall at the level of the second lumbar vertebra on the left. Following from left to right and from top to bottom, successively crossing the aorta, inferior vena cava, right ureter, it ends on the right at the level of the iliosacral joint. Blood vessels and nerves penetrate the mesentery. The mesenteric root divides the middle floor of the abdominal cavity into the right and left mesenteric sinuses.

The right mesenteric sinus (sinus mesentericus dexter) is located to the right of the root of the mesentery; medially and inferiorly it is limited by the mesentery of the small intestine, superiorly by the mesentery of the transverse colon, and on the right by the ascending colon. The parietal peritoneum lining this sinus adheres to the posterior abdominal wall; behind it lie the right kidney, ureter, blood vessels for the cecum and ascending part of the colon.

The left mesenteric sinus (sinus mesentericus sinister) is slightly longer than the right one. Its boundaries: above - the mesentery of the transverse colon (level of the II lumbar vertebra), laterally - the descending part of the colon and the mesentery of the sigmoid colon, medially - the mesentery of the small intestine. The left sinus has no lower border and continues into the pelvic cavity. Under the parietal peritoneum pass the aorta, veins and arteries to the rectum, sigmoid and descending part of the colon; The left ureter and the lower pole of the kidney are also located there.

In the middle floor of the peritoneal cavity, the right and left lateral canals are distinguished.

The right lateral canal (canalis lateralis dexter) is a narrow gap, which is limited by the lateral wall of the abdomen and the ascending part of the colon. From above, the canal continues into the hepatic bursa (bursa hepatica), and from below, through the iliac fossa, it communicates with the lower floor of the peritoneal cavity (pelvic cavity).

The left lateral canal (canalis lateralis sinister) is located between the lateral wall and the descending colon. At the top it is limited by the phrenic-colic ligament (lig. phrenicocolicum dextrum), at the bottom the canal opens into the iliac fossa.

In the middle floor of the peritoneal cavity there are numerous depressions formed by folds of the peritoneum and organs. The deepest of them are located near the beginning of the jejunum, the terminal part of the ileum, the cecum and in the mesentery of the sigmoid colon. Here we describe only those pockets that occur constantly and are clearly defined.

The duodenum-jejunal recess (recessus duodenojejunalis) is limited by the peritoneal fold of the root of the mesentery of the colon and flexura duodenojejunalis. The depth of the depression ranges from 1 to 4 cm. It is characteristic that the fold of the peritoneum that limits this depression contains smooth muscle bundles.

The superior ileocecal recess (recessus ileocecalis superior) is located in the upper corner formed by the cecum and the terminal section of the jejunum. This depression is noticeably expressed in 75% of cases.

The lower ileocecal recess (recessus ileocecalis inferior) is located in the lower corner between the jejunum and the cecum. On the lateral side it is also limited by the vermiform appendix along with its mesentery. The depth of the recess is 3-8 cm.

The postcolic recess (recessus retrocecalis) is unstable, formed due to folds during the transition of the parietal peritoneum to the visceral one and is located behind the cecum. The depth of the recess ranges from 1 to 11 cm, which depends on the length of the cecum.

The intersigmoid recess (recessus intersigmoideus) is located in the mesentery of the sigmoid colon on the left (Fig. 277, 278).

277. Pockets of the peritoneum (according to E.I. Zaitsev). 1 - flexura duodenojejunalis.

278. Pockets of the mesentery of the sigmoid colon (according to E.I. Zaitsev).

The lower floor of the peritoneal cavity is localized in the small pelvis, where folds and depressions of the peritoneum are formed. The visceral peritoneum covering the sigmoid colon continues to the rectum and covers its upper part intraperitoneally, the middle part mesoperitoneally, and then spreads in women to the posterior vaginal fornix and the posterior wall of the uterus. In men, the peritoneum passes from the rectum to the seminal vesicles and the posterior wall of the bladder. Thus, the lower part of the rectum, 6-8 cm long, lies outside the peritoneal sac.

In men, a deep cavity (excavatio rectovesicalis) is formed between the rectum and the bladder (Fig. 279). In women, due to the fact that the uterus with tubes is wedged between these organs, two depressions are formed: the rectal-uterine (excavatio rectouterina) - deeper, limited on the sides by the rectal-uterine fold (plica rectouterina), and the vesico-uterine (excavatio vesicouterina), located between the bladder and the uterus (Fig. 280). The peritoneum of the anterior and posterior surfaces of the walls of the uterus on its sides is connected into wide uterine ligaments (ligg. lata uteri), which on the lateral surface of the small pelvis continue into the parietal peritoneum. IN top edge Each broad uterine ligament contains a fallopian tube; the ovary is attached to it and the round ligament of the uterus passes between its layers.

279. Relation of the pelvic peritoneum on a sagittal section in a man (diagram).
1 - excavatio rectovesicalis; 2 - rectum; 3 - vesica urinaria; 4 - prostate; 5 - m. sphincter ani externus; 6 - urethra.

280. Relation of the pelvic peritoneum on a sagittal section in a woman (diagram).
1 - peritoneum parietale; 2 - rectum; 3 - uterus; 4 - excavatio rectouterina; 5 - vesica urinaria; 6 - vagina; 7 - urethra; 8 - excavatio vesicouterina; 9 - tuba uterina; 10 - ovarium; 11 - lig. suspensorium ovarii.

The peritoneum of the lateral walls of the pelvis is directly connected to the peritoneum of the posterior and anterior walls. In the groin area, the peritoneum covers a number of formations, forming folds and pits. In the midline on the anterior wall of the peritoneum there is a median umbilical fold (plica umbilicalis mediana), covering the bladder ligament of the same name. On the sides of the bladder are the umbilical arteries (aa. umbilicales), covered by the medial umbilical folds (plicae umbilicales mediales). Between the median and medial folds there are supravesical fossae (fossae supravesicales), which are better expressed when the bladder is emptied. 1 cm laterally from the plica umbilicalis medialis there is a lateral umbilical fold (plica umbilicalis lateralis), which arose as a result of the passage of a. And. v. epigastricae inferiores. Lateral to the plica umbilicalis lateralis, the lateral inguinal fossa (fossa inguinalis lateralis) is formed, which corresponds to the internal opening of the inguinal canal. The peritoneum between the plica umbilicalis medialis and the plica umbilicalis lateralis covers the medial inguinal fossa (fossa inguinalis medialis).

Internal organs

The lower floor of the abdominal cavity is located from the root of the mesentery of the transverse colon to the border line, i.e. entrance to the pelvic cavity. In this floor lies the small and large intestine, while the peritoneum covers them differently, as a result of which a number of depressions are formed in the places where the visceral peritoneum transitions into the parietal peritoneum and when the peritoneum passes from organ to organ - canals, sinuses, and pockets. Practical significance of these depressions is the possibility of spreading (canals) or, on the contrary, delimiting (sinuses, pockets) purulent pathological process, as well as the possibility of the formation of internal hernias (pockets) (Fig. 17).

The root of the mesentery of the small intestine is a duplication of the peritoneum with fiber, vessels and nerves located inside. It is located obliquely: from top to bottom, from left to right, starting at the level of the left half of the second lumbar vertebra and ending in the right iliac fossa. On its way, it crosses the duodenum (final section), abdominal aorta, inferior vena cava, and right ureter. The superior mesenteric artery with its branches and the superior mesenteric vein pass through its thickness.

Peritoneal sinuses and pouches

Right mesenteric sinus bounded above by the mesentery of the transverse colon, on the left and below by the root of the mesentery of the small intestine, on the right by the inner wall of the ascending colon.

Left mesenteric sinus bounded above by the root of the mesentery of the small intestine, below by the terminal line, on the left by the inner wall of the descending colon.

Rice. 17. Canals and sinuses of the lower floor of the abdominal cavity: 1 - right lateral canal; 2 - left side channel; 3 - right mesenteric sinus; 4 - left mesenteric sinus

Right side channel located between the ascending colon and the anterolateral abdominal wall. Through this channel, communication is possible between the hepatic bursa and the right iliac fossa, i.e. between the upper and lower floors of the abdominal cavity.

Left side channel lies between the anterolateral wall of the abdomen and the descending colon. In the upper part of the canal is the diaphragmatic-colic ligament, which closes the canal from above in 25% of people. Through this channel, communication is possible (if the ligament is not expressed) between the left iliac fossa and the pregastric bursa.

Peritoneal pockets. In the area of the duodenojejunal flexure there is a pouch of Treitz, or recessus duodenojejunalis. Its clinical significance lies in the possibility of true internal hernias occurring here.

In the area of the ileocecal junction, three pouches can be found: the upper and lower ileocecal, located respectively above and below the junction, and the retrocecal, lying behind the cecum. These pockets require special attention from the surgeon when performing an appendectomy.

Between the loops of the sigmoid colon there is an intersigmoid pouch (recessus intersigmoideus). Internal hernias can also occur in this pocket.

Blood vessels(Fig. 18). At the level of the body of the first lumbar vertebra from abdominal aorta the superior mesenteric artery arises. It enters the root of the mesentery of the small intestine and branches into its terminal branches. At the level of the lower edge of the body of the third lumbar vertebra, the inferior mesenteric artery departs from the aorta. It is located retroperitoneally and gives branches to the descending colon, sigmoid and rectum.

Rice. 18. Branches of the superior and inferior mesenteric arteries: 1 - superior mesenteric artery; 2 - middle colon artery; 3 - right colon artery; 4 - ileocecal artery; 5 - artery of the vermiform appendix; 6 - jejunal arteries; 7 - ileal arteries; 8 - inferior mesenteric artery; 9 - left colon artery; 10 - sigmoid arteries; 11 - superior rectal artery

Rice. 19. Portal vein and its tributaries (from: Sinelnikov R.D., 1979). I - esophageal veins; 2 - left branch of the portal vein; 3 - left gastric vein; 4 - right gastric vein; 5 - short gastric veins; 6 - splenic vein; 7 - left gastroepiploic vein; 8 - veins of the omentum; 9 - left renal vein; 10 - site of anastomosis of the middle and left colon veins; II - left colic vein; 12 - inferior mesenteric vein; 13 - jejunal veins; 14, 23 - common iliac veins; 15 - sigmoid vein; 16 - superior rectal vein; 17 - internal iliac vein; 18 - external iliac vein; 19 - middle rectal vein; 20 - inferior rectal vein; 21 - rectal venous plexus; 22 - vein of the appendix; 24 - ileocolic vein; 25 - right colon vein; 26 - middle colon vein; 27 - superior mesenteric vein; 28 - pancreatoduodenal vein; 29 - right gastroepiploic vein; 30 - peri-umbilical veins; 31 - portal vein; 32 - right branch of the portal vein; 33 - venous capillaries of the liver; 34 - hepatic veins

Venous blood from the organs of the lower floor flows into the superior and inferior mesenteric veins, which, merging with the splenic vein, form the portal vein (Fig. 19).

Nerve plexuses

Nerve plexuses the lower floor is represented by parts of the aortic plexus: at the level of the origin of the superior mesenteric artery there is the superior mesenteric plexus, at the level of the origin of the inferior mesenteric plexus there is the inferior mesenteric plexus, between which lies the intermesenteric plexus. Above the entrance to the pelvis, the inferior mesenteric plexus passes into the superior hypogastric plexus. These plexuses provide innervation to the small and large intestines.

Groups of lymph nodes

Lymphatic system The small intestine is similar to the arterial one and is represented by several rows of lymph nodes. The first row is located along the marginal artery, the second - next to the intermediate arcades. The third group of lymph nodes lies along the superior mesenteric artery and is common to the small intestine and part of the colon. The lymphatic system of the colon also consists of several rows, the first lying along the mesenteric edge of the intestine. In this series, the groups of lymph nodes of the cecum, ascending, transverse colon, descending colon and sigmoid colon are distinguished. At the level of the arcades lies the second row of lymph nodes. Finally, along the trunk of the inferior mesenteric artery lies the third row of lymph nodes. At the level of the second lumbar vertebra, the thoracic lymphatic duct is formed.