Development of the endocrine system alpha cells. The insulin concentration within the fetal pancreas is 3.6 pmol/g at seven to ten weeks, which rises to 30 pmol/g at 16–25 weeks of gestation. Near term, the insulin concentration increases to 93 pmol/g. The endocrine cells have dispersed throughout the body within 10 weeks. At 31 weeks of development, the islets of Langerhans have differentiated. While the fetal pancreas has functional beta cells by 14 to 24 weeks of gestation, the amount of insulin that is released into the bloodstream is relatively low. In a study of pregnant women carrying fetuses in the mid-gestation and near term
Chain Islets Chain Islets The Chain Islets and Great Chain Island (occasionally Great Chain Islet) are a group of at least 18 islets situated off the east coast of Oak Bay, British Columbia, Canada. They lie in Mayor Channel about halfway between Mary Tod Island (W) and Discovery Island (E). Most of the islets are very small, rocky, and are unnamed, except for Great Chain Island which is covered in grass and herbaceous cover with occasional shrub thickets. The islets are noted as an important gathering place for harbor seals in the summer and for many seabirds such as seagulls and cormorants.