Pancreas

The pancreas is a bodily organ that plays a role in the digestive system and produces a number of hormones.

In humans the pancreas is a small elongated organ connected to the duodenum. It is covered by a tissue capsule which partitions the gland into lobules. The bulk of the pancreas is composed of pancreatic exocrine cells and their ducts arranged in clusters called acini (singular acinus), the cells are filled with secretory granules containing the digestive enzymes (mainly trypsin, chymotrypsin, pancreatic lipase and amylase) that are exocytosed into the lumen of the acinus. From there the secretions aggregate into intralobular ducts and then the main pancreatic duct which drains directly into the duodenum.

Embedded throughout the exocrine tissue are small clusters of cells called the Islets of Langerhans, which are the endocrine cells of the pancreas and secrete insulin, glucagon and several other hormones. The Islets contain three different types of cells - Alpha cells (glucagon producing), Beta cells (the most numerous, insulin producing) and Delta Cells (somatostatin producing).