Explanation

Pancreas is a heterocrine gland $i.e.,$ partly endocrine and partly exocrine. The exocrine part secretes pancreatic juice. The endocrine part is formed of islets of Langerhans. Islets of Langerhans are composed of three types of cells— Alpha cells: secrete glucagon hormone. Beta cells: secrete insulin hormone. Gamma cells: precursors of alpha and beta cells.