The pancreas is often described as a "mixed gland" because it consists of exocrine as well as endocrine regions. The exocrine areas are composed primarily of pancreatic acinar cells, which help produce chemicals that facilitate digestion.

The endocrine regions are referred to as pancreatic_islets (islets_of_Langerhans). The islets are composed of several cell types, including alpha_cells, which produce glucagon and beta_cells, which produce insulin.