The endocrine function is centered in the islets of Langerhans, which contain alpha and beta cells that secrete glucagon and insulin respectively. Insulin stimulates the muscles to remove glucose from the blood. It is also responsible for spurring both muscles and liver to convert glucose to glycogen, the storage form of glucose. The islets of Langerhans also secrete glucagon, which responds to low concentrations of blood glucose by stimulating the breakdown of glycogen into glucose.
This animation (Audio - Important) describes pancreatic hormones.