Final answer:
Insulin is produced by the beta cells in the pancreatic islets of the pancreas, which are essential for regulating blood glucose levels.
Step-by-step explanation:
Insulin is produced by the beta cells of the pancreas. The pancreatic islets or islets of Langerhans contain several types of cells that play a crucial role in regulating blood glucose levels. Of these, alpha cells produce glucagon, which raises blood glucose levels, while beta cells produce insulin, which lowers the blood glucose levels by facilitating the uptake of glucose into the body's cells. In addition, the delta cells secrete somatostatin, which inhibits the release of both glucagon and insulin, and the PP cells, or gamma cells, secrete pancreatic polypeptide, involved in appetite regulation and pancreatic secretions.