(i) The endocrine cells present in the pancreas are alpha cells, beta cells and delta cells
(ii) The alpha cells secrete glucagon, the beta cells secrete insulin, and the delta cells secrete somatostanin.
(iii) Insulin lowers the blood glucose level by increasing the absorption of glucose.
Glucagon increases the blood glucose level by increasing the breakdown of glycogen.
Somatostanin inhibits the secretion of glucagon and insulin.