Cell Types : Pancreatic acinar cells 2. Endocrine cells.

Digestive System
1. Pancreatic acinar cells. Each acinus consists of several pyramid-shaped, enzyme secreting cells whose apices border on a small lumen and whose bases abut a basal lamina. Acinar cells synthesize a wide variety of enzymes that can hydrolyze proteins (proteases, such as trypsin, chymotrypsin, and elastase), lipids (lipases, such as triacylglycerol lipase and phospholipase A,), carbohydrates (amylase), and nucleic acids (ribonuclease and deoxy ribonuclease). Enzymes are packaged and stored in the acidophilic apical region as membrane-bound zymogen granules. Here they await exocytosis in response to stimulation by cholecystokinin, which is produced by enteroendocrine cells in the small intestine, or parasympathetic stimulation via the vagus nerve. The enzymes in the granules are zymogens, which are inactive before the release. One such zymogen, trypsinogen, is enzymatically converted to the active protease trypsin in the small intestine by enterokinase, an enzyme that is secreted by enterocytes.


2. Endocrine cells.