Final answer:
The Ventral and Dorsal Pancreatic buds fuse during pancreatic development, a process regulated by embryonic germ layers and genetic factors, resulting in the formation of the exocrine pancreas. The exocrine pancreas, made up of acinar cells, secretes pancreatic juice into the digestive system, regulated at the hepatopancreatic ampulla.
Step-by-step explanation:
The fusion of the Ventral and Dorsal Pancreatic buds is a crucial aspect of pancreatic development during embryogenesis. This process is part of organogenesis, which is regulated by the embryonic germ layers formed during gastrulation. The exocrine pancreas develops from these buds, with the ventral bud giving rise to the uncinate process and main pancreatic duct, while the dorsal bud forms the remainder of the gland and duct system. As development progresses, the ventral bud rotates posteriorly and fuses with the dorsal bud. This complex developmental process is orchestrated by signaling molecules and genetic factors that guide the proliferation, differentiation, and fusion of these primitive structures.
The exocrine part of the pancreas, consisting of acinar cells, arises from these buds, with the cells secreting enzyme-rich pancreatic juice that travels through a ductal network. The main pancreatic duct eventually joins the common bile duct to form the hepatopancreatic ampulla (ampulla of Vater), allowing the secretion of pancreatic enzymes into the duodenum. The second, smaller duct, known as the accessory duct or duct of Santorini, may also be present as a remnant of the developmental process.
The hepatopancreatic ampulla, located in the duodenal wall, is where the secretion of both bile and pancreatic juice is regulated by the hepatopancreatic sphincter (sphincter of Oddi) before entering the duodenum. The precise coordination between these various components ensures the proper functioning of the digestive system.