Development of organs within the mesentery

Some abdominal organs are derived from the primitive gut tube, others develop from the mesentery itself.

The stomach develops as a dilation in the primitive gut tube. Just distal to the pyloric sphincter, the liver buds out anteriorly into the ventral mesentery. The small ventral bud of pancreas (VBOP) buds out anteriorly into the ventral mesentery, whilst the larger dorsal bud of pancreas (DBOP) buds out posteriorly into the dorsal mesentery. The spleen develops within the dorsal mesentery, immediately posterior to the stomach, between it and the posterior wall of the abdomen.

At this stage of development, parts of the double layer of mesentery between certain organs are given particular names:

From anterior to posterior, a transverse section through the abdomen at the level of the stomach includes -

• the anterior abdominal wall
• the falciform ligament
• the liver
• the lesser omentum
• the stomach
• the gastrosplenic ligament
• the spleen
• the lienorenal ligament
• the posterior abdominal wall (with the kidneys posterior to the peritoneum - retroperitoneal)