The mesentery refers to a “mesentery” that serves as the suspensory ligament of the intestine. In a broader sense, all mesenteries of the organs located within the peritoneum are referred to as mesenteries.
What is the mesentery?
The mesentery is also called the mesentery or meso and is a duplication of the peritoneum, the peritoneum. It functions as a “suspensory ligament” of the intestine and originates from the posterior abdominal wall. The intestine is partially attached to the mesentery, which allows for fixation while allowing for mobility. In a broader sense, the term mesentery is used to refer to all the mesenteries of the organs located within the peritoneum. In a narrower definition, the mesentery refers only to the mesentery of the small intestine, more specifically the ileum and jejunum.
Anatomy and structure
The respective intestinal segments are partially suspended from the mesenteries, which ensures that they remain mobile despite being somewhat fixed. To supply the intestine, the mesenteries contain lymphatics, connective and adipose tissue, nerves, and vessels. The mesentery merges with the serosa of the intestine at the intestinal loops. Attachments of the mesentery remote from the organs are called the “gekrösewurzel” (radix mesenterii). At the radix mesenterii, the visceral and parietal sheets of the peritoneum meet. A mesentery stretched between two organs is called a ligament. There are different mesenteries in the human body, some being present only in the embryonic stage and regressing later. The mesenteries can be divided into:
- Mesogastrium
The mesogastrium consists of two parts, the ventral mesogastrium and the dorsal mesogastrium. The ventral mesogastrium is the anterior mesentery of the stomach, while the ventral mesogastrium is the posterior. The mesogastrium develops during the embryonic period and merges with various other structures as the body develops. The ventral mesogastrium, which exists during the embryonic stage, can in turn be divided into the ventral and dorsal mesohepaticum. The ventral mesohepaticum develops into the ligamentum falciforme hepatis. The mesohepaticum dorsale develops into the omentum minus. The mesogastrium dorsale, the posterior mesentery of the stomach, develops into the omentum majus as well as the ligamentum gastrolienale, ligamentum gastrocolicum, ligamentum gastrophrenicum, ligamentum phrenicolienale, and ligamentum phrenicocolicum.
- Mesoduodenum
The mesoduodenum is the mesentery of the duodenum. It develops during the embryonic period. It can be divided into the mesoduodenum dorsal (the posterior mesoduodenum) and the mesoduodenum ventral (the anterior mesoduodenum). The dorsal mesoduodenum is where the anlage of the pancreas (pancreas) develops. After the embyrional stage, it fuses with the posterior abdominal wall with the backward displacement of the duodenum. The ventral mesoduodenum, together with the ventral mesogastrium, becomes the omentum minus, which can be divided into the hepatogastric ligament and the hepatoduodenal ligament.
- Mesojejunum
The mesojejunum is the mesentery of the jejunum. It is attached to the posterior abdominal wall along with the mesoileum. The mesojejunum contains the jejunal arteries and the jejunal veins from the superior mesenteric artery and superior mesenteric vein, respectively, as well as nerve fibers and lymphatic vessels that supply the small intestine.
- Mesoileum
The mesoileum is the mesentery of the ileum. It is attached to the posterior abdominal wall together with the mesentery of the jejunum (mesojejunum). The site of attachment is called the radix mesenterii. The mesoileum contains the ileal arteries and the ileal veins from the superior mesenteric artery and the superior mesenteric vein, respectively, as well as nerve fibers and lymphatic vessels that supply the ileum.
- Mesorectum
The mesorectum is the mesentery of the rectum (rectum). It connects the rectum with the sacrum (sacrum). Furthermore, there is also the mesocolon, which can be divided into:
- Mesocolon transversum
The mesocolon transversum is the mesentery of the transverse colon, the middle portion of the colon. Together with the gastrocolic ligament, it forms the inferior recess of the bursa omentalis.
- Mesocolon sigmoideum
The mesocolon sigmoideum is the mesentery of the sigmoid colon (sigmoid). It forms the recessus intersigmoideus above the left psoas major muscle.It is very mobile overall, but is fixed at the junctions with the rectum and descending colon.
- Mesoappendix
The mesoappendix is the mesentery of the appendix vermiformis, the appendix of the vermiform appendix. The mesoappendix represents a peritoneal duplication and may extend to the tip of the appendix. It connects the appendix with the ileum. Furthermore, it contains the appendicular artery, appendicular vein, and lymphatic vessels and nerves.
Function and tasks
The mesentery as a generic term stands for a “mesentery” that forms the suspensory ligament of the intestine. It guarantees fixation of the intestine while allowing it to move. The other functions of the various mesenteries can be briefly summarized by the fact that nerves, lymphatic channels and vessels run through them, supplying the respective organs. Specifically, the exact function and task of the mesentery is related to the organ being supplied.
Diseases
In connection with the mesentery, a so-called volvulus, a rotation of a section of the digestive tract around its mesenteric axis, is conceivable as a possible complaint or disease. This rotation restricts the blood supply to the affected section, which passes through the mesentery. Intestinal obstruction and the loss of intestinal tissue (intestinal gangrene) are possible. Acute volvulus represents a surgical emergency. Furthermore, anatomic malformations of the mesenteries and injury to the mesenteries from external causes, such as gunshot or stab wounds, are possible.
