Islets of Langerhans
Known as the insulin-producing tissue, the islets of Langerhans do more than that. They are groups of specialized cells in the pancreas that make and secrete hormones. Named after the German pathologist Paul Langerhans (1847-1888), who discovered them in 1869, these cells sit in groups that Langerhans likened to little islands in the pancreas. There are five types of cells in an islet: alpha cells that make glucagon, which raises the level of glucose (sugar) in the blood; beta cells that make insulin; delta cells that make somatostatin which inhibits the release of numerous other hormones in the body; and PP cells and D1 cells, about which little is known. Degeneration of the insulin-producing beta cells is the main cause of type I (insulin-dependent) diabetes mellitus.

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pancreatic islets irregular microscopic structures scattered throughout the pancreas and comprising its endocrine part (the endocrine pancreas). They are composed of at least four types of cells: the alpha cells, which secrete glucagon; the beta cells, which are the most abundant and secrete insulin; the delta cells, which secrete somatostatin; and the PP cells, which secrete pancreatic polypeptide. Degeneration of the beta cells, whose secretion (insulin) is important in carbohydrate metabolism, is the major cause of type I diabetes mellitus. Called also insulae pancreaticae [TA], islands of Langerhans, and islands of pancreas.

Pancreatic islet (I), surrounded by acinar tissue. Blood vessels (V) and a small duct (D) are also shown.

Pancreatic islet in early type 1 diabetes mellitus; on the left side it has been infiltrated with T lymphocytes and beta cells are not seen, while on the right the remaining beta cells stain brown with antibody to insulin.


Medical dictionary. 2011.

Look at other dictionaries:

  • Islets of Langerhans — is the area in which the endocrine (i.e., hormone producing) cells of the pancreas are grouped. Discovered in 1869 by the famous German pathological anatomist Paul Langerhans, the islets of Langerhans constitute approximately 1 to 2% of the mass… …   Wikipedia

  • islets of Langerhans — or islands of Langerhans [läŋ′ər hänz΄] n. 〚after P. Langerhans (1847 88), Ger histologist〛 irregular groups of endocrine cells in the pancreas that produce the hormone insulin: their degeneration may cause diabetes mellitus * * * …   Universalium

  • islets of Langerhans — or islands of Langerhans [läŋ′ər hänz΄] n. [after P. Langerhans (1847 88), Ger histologist] irregular groups of endocrine cells in the pancreas that produce the hormone insulin: their degeneration may cause diabetes mellitus …   English World dictionary

  • islets of Langerhans — ► PLURAL NOUN ▪ groups of cells in the pancreas that secrete the hormones insulin and glucagon. ORIGIN named after the German anatomist Paul Langerhans (1847 88) …   English terms dictionary

  • islets of Langerhans — noun cell clusters in the pancreas that form the endocrine part of that organ; secrete insulin and other hormones • Syn: ↑islands of Langerhans, ↑isles of Langerhans • Hypernyms: ↑endocrine gland, ↑endocrine, ↑ductless gland • …   Useful english dictionary

  • islets of Langerhans — /ˌaɪləts əv ˈlæŋəhæns/ (say .uyluhts uhv languhhans) plural noun See pancreas. Also, islands of Langerhans. {named after Paul Langerhans, 1847–88, German physician} …   Australian English dictionary

  • islets of Langerhans — small groups of endocrine cells scattered through the material of the pancreas. There are three main histological types: alpha (a) cells, which secrete glucagon; beta (b) cells, which produce insulin; and delta (d) cells, which release… …   Medical dictionary

  • islets of Langerhans — small groups of endocrine cells scattered through the material of the pancreas. There are three main histological types: alpha (α) cells, which secrete glucagon; beta (β) cells, which produce insulin; and D cells, which release somatostatin and… …   The new mediacal dictionary

  • islets of Langerhans — [ laŋəhanz] plural noun groups of pancreatic cells secreting insulin and glucagon. Origin C19: named after the German anatomist Paul Langerhans …   English new terms dictionary

  • Islets of Langerhans — Groups of cells found within the pancreas: A cells and B cells secrete insulin and glucagon. See also D cells …   Dictionary of molecular biology

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