Centroacinar cells are spindle-shaped cells in the exocrine pancreas. Centroacinar cells are an extension of the intercalated duct cells into each pancreatic acinus. The intercalated ducts take the bicarbonate to intralobular ducts which become lobular ducts. These lobular ducts finally converge to form the main pancreatic duct. Centroacinar cells are spindle-shaped cells in the exocrine pancreas. Centroacinar cells are an extension of the intercalated duct cells into each pancreatic acinus. The intercalated ducts take the bicarbonate to intralobular ducts which become lobular ducts. These lobular ducts finally converge to form the main pancreatic duct. These cells are commonly known as duct cells, and secrete an aqueous bicarbonate solution under stimulation by the hormone secretin. They also secrete mucin. This article incorporates text in the public domain from page 1204 of the 20th edition of Gray's Anatomy (1918)