Development of the Pancreas

• The pancreas is derived from endoderm in the primitive gut. Two primordia (protrusions) from the primitive gut are precursors for the pancreas.
• The ventral primordia moves over to the dorsal side were the primordia fuse and form the pancreas.
  
• The liver, gall bladder, and bile duct also develop from the ventral primordia.
• The dorsal and ventral primordia grow and differentiate into different cell types.

• Interactions from gene products in the developing pancreas produce the first of the primative tubules, islet cells, acinar cells, and mature ducts. The blood vessels, lymphatics, and connective tissue develop from mesodermly derived mesenchyme within the developing pancreas.
• The ductal cells produce the definitive ductular and ductual epithelial cells that form the ducts. The acinar cells remain within the confines of the primitive ductuals. While the endocrine system cells from the primitive epithelial cells migrate into the mesenchyme and aggregate into groups, producing the islets of Langerhans.
  
• Mesodermly derived cells in the mesenchyme differentiate into blood vessel forming cells. These vessels form a network of arteries, capillaries, and veins which connects with and is supplied by the aorta. The network connects with the venous system and drains through the hepatic portal vein.
• The extensive nervous system from the nerve fiber cells (neural crest cells) from different parts of the general nervous system. These nerves form connections with the central nervous system as well as the enteric nervous system (Beger ET AL 2008).