The Exocrine and Endocrine Pancreas: Embryology and Histology

The pancreas is both an exocrine and an endocrine gland. The exocrine part is arranged in acini. The exocrine secretion products are collected and delivered by a duct system which is drained by the pancreatic ducts. The endocrine component is composed of small clumps of cells, named the islets of Langerhans, which are scattered throughout the exocrine glandular tissue. The history of the endocrine pancreas has been recently reviewed (Samols 1991).