Final answer:
The pancreas releases insulin and glucagon through the islets of Langerhans, which contain alpha and beta cells respectively responsible for glucose regulation.
Step-by-step explanation:
The structure that releases insulin and glucagon is the pancreas. Within the pancreas, there are specialized clusters of endocrine cells known as the islets of Langerhans. These islets contain alpha cells that release glucagon, which raises blood glucose levels, and beta cells that release insulin, which lowers blood glucose levels. This regulation of blood glucose is crucial for maintaining the body's energy balance and is especially important for individuals with diabetes.