Mesoduodenum

The mesoduodenum is the portion of the mesentery associated with the duodenum, the first segment of the small intestine.

The mesoduodenum is a derivative of the dorsal mesentery that suspends the duodenum from the dorsal abdominal wall. It is especially well-developed in domestic mammals but lack in humans (duodenum firmly adheres to the posterior abdominal wall)

As the duodenum is divided into several parts ( Cranial part (including the duodenal ampulla and cranial flexure), descending duodenum, caudal flexure, ascending duodenum), the mesoduodenum can be correspondingly further divided into:

• Cranial mesoduodenum: Often indistinct; it merges with the greater omentum and hepatoduodenal ligament.

• Descending mesoduodenum: More prominent; it suspends the descending portion of the duodenum and contains the right lobe of the pancreas.

• Caudal mesoduodenum: Less distinct but continues the mesentery at the caudal flexure.

• Ascending mesoduodenum: Suspends the ascending duodenum and transitions into the mesojejunum.

Structural Features of the mesoduodenum

• Location and Attachments:

  • Attaches the duodenum to the dorsal abdominal wall.

  • Lies caudal and dorsal to the root of the mesentery.

  • Located near the right kidney and caudal vena cava, often making it a key reference point in surgical procedures.

• Contents:

  • Pancreas (especially the right lobe in most domestic animals)

  • Duodenal lymph nodes

  • Duodenal branches of cranial mesenteric vessels

  • Bile duct (runs toward the duodenum through the hepatoduodenal ligament, not strictly within the mesoduodenum but associated)