The ducts of the exocrine pancreas The intercalated ducts are formed by low cuboidal epithelium. The nucleus is ovoid with inconspicuous nucleoli. The intralobular ducts vary in diameter. Lined by simple cuboidal epithelium. A single rounded nucleus appears to fill each cell.
Interlobular ducts are larger and are lined by simple columnar epithelium.
They are invested by a layer of collagenous tissue. Two major ducts are the ducts of Santorini and Wirsung. They have tall columnar epithelium with basal nuclei. Merocrine secretion of proenzymes by the acinar cells is regulated by secretin, cholecystokinin, and nerve stimulation from the vagus. The endocrine cells form scattered aggregates that form the Islets of Langerhans.