Function of the pancreatic islets

Inside the pancreas there are islands of cells with a hormonal job: the pancreatic islets, also called the islets of Langerhans. Four hormones are released from them: glucagon, insulin, somatostatin, and pancreatic polypeptide.

Two of the islet cells divide the work, pulling in opposite directions, and that is where the elegance is. The beta cell, which is the most abundant and makes up about 75 percent of each islet, produces insulin, and what wakes it up is high blood glucose. The alpha cell, about 20 percent of the islet, produces glucagon, and what wakes it up is the opposite: low glucose. It is like the two taps on a sink, the hot one and the cold one: one goes into action when there is too much sugar and the other when there is not enough. And there is a third voice calling for calm: pancreatic somatostatin is an inhibitory hormone and it slows the release of both glucagon and insulin.