A PAS stain demonstrates the abundant glycogen that is present within the cytoplasm of the hepatocytes. The process of glycogen storage is promoted by the hormone insulin from beta cells of pancreatic islets, while glycogenolysis with gluconeogenesis is stimulated by glucagon release from alpha cells of the islets of Langerhans. Bile canaliculi between the plates of hepatocytes drains toward the triad at the left.