A light and electron microscopic study on the pancreatic ductal system.

To investigate morphological features of the human pancreatic ductal system, light and electron microscopic studies were performed, on the comparative basis with those of several species of mammals. The human pancreas possessed relatively well-developed ductal system, as compared with those of other mammals. Furthermore, it had unique centroacinr cells containing numerous mitochondria. The mode of innervation to the ducts, and cytological features such as cilia formation and mucin production were also revealed. Several kinds of endocrine cells including A, B, D1, ECn, presumptive EC1, and presumptive EC2 or K could be identified, but a few remained unclassifiable. The above findings are considered to be prerequisite for understanding the physiology, especially of bicarbonate production, and pathology, especially of oncogenesis of the exocrine and endocrine pancreas.