Insulin oscillation oscillations. The insulin oscillations are generated by pulsatile release of the hormone from the pancreas. Insulin originates from beta cells located in the islets of Langerhans. Since each islet contains up to 2000 beta cells and there are one million islets in the pancreas it is apparent that pulsatile secretion requires sophisticated synchronization both within and among the islets of Langerhans. Pulsatile insulin secretion from individual beta cells is driven by oscillation of the calcium concentration in the cells. In beta cells lacking contact, the periodicity of these oscillations is rather variable (2-10 min). However, within an islet of Langerhans
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.