The document discusses the endocrine pancreas and its role in regulating blood sugar levels. The endocrine pancreas contains clusters of cells called islets of Langerhans, which include alpha cells that produce glucagon, beta cells that produce insulin, and delta cells that produce somatostatin. Insulin lowers blood sugar by facilitating glucose uptake and storage, while glucagon raises blood sugar by promoting glucose release and production. Somatostatin inhibits the secretion of insulin and glucagon to regulate their levels.