Pancreatic islets of Langerhans are small nests of cells, arranged into curvilinear cords, scattered throughout the pancreas.
Islets are usually conspicuously paler (less intensely stained) than the acini of the exocrine pancreas, but in any case islets differ markedly from exocrine pancreas in the arrangement of cells (cords rather than acini).
Pancreatic islets contain several endocrine cell types secreting insulin (beta cells), glucagon (alpha cells), somatostatin (delta cells), and pancreatic polypeptide (PP cells). These cells cannot be readily distinguished in routine preparations but may be identified with special stains. (See WebPath for images of immunological staining of insulin- and glucagon-secreting cells).
SIUC / School
of Medicine / Anatomy / David
Last updated: 18 November 2002 / dgk