The pancreas sits in a bend of the duodenum, conveniently placed for its work in digestion. In its other role is as an endocrine gland, it makes two hormones that regulate the everyday fluctuations in blood glucose levels. They come from two different clusters of cells in the islets of Langerhans. When glucose enters the blood after a meal, insulin is secreted to limit its level. It does this mainly by speeding the entry of glucose into the cells. It also accelerates the conversion of glucose to glycogen for storage.
The other pancreatic hormone, glucagon, has the opposite effect. Secreted when the level of blood glucose falls below normal, it accelerates the conversion of glycogen in the liver to glucose and helps the liver to convert other nutrients such as amino acids and fats into glucose.
