The so-called mesogastria refer to the two mesenteries in the stomach, whose development and formation takes place during the embryonic period. The mesogastrium represents the areas of the human abdomen, organs as well as the abdominal wall. These are located between the navel and the junction of both spinae iliacae anteriores superiores.
What is a mesogastrium?
The dorsal mesogastrium refers to the posterior portion of both mesogastria. In this area, the development of the spleen occurs as a result of mesenchymal proliferation. Development occurs to the stage of the omentum majus and the ligamentum gastrolienales as well as the ligamentum gastrocolicum. Further, the ligamentum gastrophrenicum, the ligamentum phrenicolienale and the ligamentum phrenicocolicum follow. The ventral mesogastrium refers to the mesogastrium present in the anterior region. At this point, the ventral and dorsal mesohepaticum arise because the cells of the hepatic anlage grow into the mesogastrium. From the so-called ventral mesohepaticum, the ligamentum falciforme hepatis grows in the anlage. The mesohepaticum dorsale gives rise to the omentum minus and its two parts. These denote the ligamentum hepatogastricum and the ligamentum hepatoduodenale.
Anatomy and structure
The human stomach is connected to the dorsal wall by the mesogastrium. This is connected to the transverse septum by means of a duplicate of the so-called peritoneum. The ventral connection is represented by the mesogastrium ventrale. As the liver develops during the embryonic period, a ventral protrusion of the intestinal tubes into the septum transversum develops here. The connecting form, called the ventral mesogastrium, develops into what is called the ligamentum hepatogastricum or the omentum minus. The peritoneal cavity refers to the celomic cleft at the level of the midgut. This has a cranial left and right extension at the liver and eventually terminates in a visceral covering of this organ. Ventrally, there remains a duplication of the peritoneum called the ligamentum falciforme. The stomach is displaced leftward, causing a 90-degree rotation. However, this represents only the result of greater growth of the later anterior wall from the stomach as well as the fundus from active rotation. This creates a small bridge in the connective tissue of the stomach and the stomach wall in the posterior region opens into a large fold, the so-called mesogastrium dorsale. This is also where the pancreas as well as the spleen are formed later in the process. This is due to the different growth rates, which largely determine the position and shape of the stomach and its different sections. Therefore, the so-called duodenum with the anlagen for the pancreas is already present at an early stage on the posterior abdominal wall. Thus, the location is no longer shown in an intraperitoneal manner but is secondarily shown retroperitoneally. Thus, the connection to the vascular-pancreatic pedicle is formed. Thus, the development of the diaphragm is responsible for the caudal displacement of the anterior intestine and ends in the final fixation of the so-called esophageal passage and the formation of the aforementioned vascular-pancreatic pedicle. Thus, the pylorus and cardia are fixed, and the growth of the stomach ultimately consists only of left horizontal displacement of the organs and the aforementioned 90-degree rotation of the same.
Function and tasks
The so-called mesenteries cause fixation of the intestinal tube to the posterior wall in the human abdomen. This is where the nerves and blood vessels of the individual organs are located. The fact that individual areas of these mesenteries partially reconnect to the abdominal wall accounts for the secondary retroperitoneal course of nerves and vessels. At the level of the stomach, as well as in the region of the small intestine and the hepatic anlage, a firm ventral connection is formed. This represents the so-called mesogastrium ventrale. In further development, the A.hepatica, the V.portae as well as the Ductus choledochus will run here. The so-called dorsal meso represents here the fixation of the organs which reach the dorsal abdominal wall. In the area of the small intestine, the mesenteric conditions are more difficult due to the rotation of the intestine, because this rotation of the mesentery in the entire area of the small intestine means that there is only one location above the so-called pars inferior of the duodenum. Furthermore, during fetal development, there is a displacement of the mesentery from the ascending and descending colon to the posterior abdominal wall.A secondary retroperitoneal junction then develops here, giving rise to the radix mesenterii, which crosses the entire posterior abdominal wall from the caecum to the flexura duodeno jejunalis. This resembles the part of the mesentery of the ascending colon fused to the posterior abdominal wall. This junction does not arise at the level of the so-called sigmoid. This area remains in intraperitoneal connection with the mesosigmoideum. The rectum is located caudal or dorsal to the peritoneal area. This is then referred to as retroperitoneal attachment.
Diseases
Finally, the mesentery is associated with the so-called volvulus. This refers to the rotation of an area of the digestive tract that occurs about the mesenteric axis. This rotation is considered to be the cause of common complaints and diseases. The reason for this is the restricted blood supply to the area affected by the rotation, which runs along the mesentery. This restriction can cause life-threatening intestinal obstructions as well as the death of tissue in the intestine. The so-called acute volvulus is a surgical emergency in any case. In this case, immediate hospital admission should be made. The range of complaints and diseases often extends to malformations of the anatomy in the mesenteries. Injuries of various types are also possible, for example, from external agents such as stab wounds or gunshot wounds.