The pancreas consists of two major types of secretory tissues. This reflects its dual function as an exocrine gland that secretes digestive juice and as an endocrine gland that releases hormones.
The exocrine function of the pancreas is localized in the acinar cells that synthesize and secrete digestive juices. The endocrine function of the pancreas is localized in the islet cells (islets of Langerhans), which synthesize and secrete hormones including insulin and glucagon.