In what structure do Beta (β) cells reside in the pancreas?

Beta (β) cells are specialized cells located in the Islets of Langerhans in the pancreas. These islets are clusters of hormone-secreting cells that play a crucial role in glucose metabolism. Beta cells specifically produce and secrete insulin, a hormone that helps regulate blood sugar levels. The Islets of Langerhans also contain other cell types, such as alpha cells, which produce glucagon, further contributing to the balance of blood glucose.

The pancreatic duct is involved in the transport of digestive enzymes but does not contain endocrine cells like beta cells. Exocrine acini are structures that produce digestive enzymes and are part of the exocrine function of the pancreas, not the hormone-producing function. The gallbladder, on the other hand, stores bile produced by the liver and does not have any direct association with insulin or beta cells. Thus, the Islets of Langerhans are the correct location for the beta cells responsible for insulin production in the pancreas.