The Islets of Langerhans are clusters of cells in the pancreas that produce and secrete hormones, including insulin, which regulates blood sugar levels. Synonyms for Islets of Langerhans include pancreatic islets, islets of the pancreas, and Langerhans Islands. These structures were named after the German physician Paul Langerhans who first described them in 1869. Other terms used to refer to the Islets of Langerhans include endocrine pancreas or endocrine cells of the pancreas. These structures are crucial to the proper functioning of the body's metabolism, and disruptions in their activity can lead to diabetes and other hormonal disorders.