The islets of Langerhans are small clusters of cells located in the pancreas. They play a crucial role in regulating blood sugar levels by producing hormones such as insulin and glucagon. These hormones help control how the body uses and stores glucose. Each islet contains different types of cells, including alpha cells, which produce glucagon, and beta cells, which produce insulin. The balance of these hormones is essential for maintaining proper metabolism and energy levels in the body. Dysfunction in the islets can lead to conditions like diabetes.