The neck arises from the left upper part of the front of the head. The endocrine part is composed of hormonal tissue distributed along the pancreas in discrete units called islets of Langerhans. Islets of Langerhans have a organ that produces hormones and enzymes that aid in digestion-established structure and form density routes through the exocrine tissue. These supply the head of the pancreas. With increasing diameter, several layers of columnar cells may be seen.
The size of the pancreas varies considerably. The pancreas develops from these buds on either side of the duodenum. This condition has no physiologic consequence. An additional ventral lobe that usually regresses during development is omitted. Each structure communicates with the foregut through a duct. Differential rotation and fusion of the ventral and dorsal pancreatic buds results in the formation of the definitive pancreas.
Upon reaching its final destination, the ventral pancreatic what role do enzymes play in process of digestion fuses with the much larger dorsal pancreatic bud. At this point of fusion, the main ducts of the ventral and dorsal pancreatic buds fuse, forming the main pancreatic duct. Differentiation of cells of the pancreas proceeds through two different pathways, corresponding to the dual endocrine and exocrine functions of the pancreas. Development of the exocrine acini progresses through three successive stages. These are the predifferentiated, protodifferentiated, and differentiated stages, which correspond to undetectable, low, and high levels of digestive enzyme activity, respectively. Blood glucose levels are maintained at a constant level in the body by a negative feedback mechanism. When the blood glucose level is too high, the pancreas secretes insulin and when the level is too low, the pancreas then secretes glucagon.