Insulin is defined as the hormone released from the beta cells of the islets of Langerhans in response to elevated blood glucose and amino acid concentrations; increases tissue uptake of both. Insulin is likewise the major endocrine hormone secreted by the islet cells of the pancreas. It facilitates the use of glucose by the body’s cells and plays a major role in the metabolism of food; pancreatic hormone that facilitates the entry of glucose into the cells