Which structure forms the endocrine portion of the pancreas?

• A. Pancreatic acini
• B. Pancreatic ducts
• C. Main pancreatic (Wirsung) duct
• D. Pancreatic islets (islets of Langerhans)

Answer: (D)

Verified step by step guidance

1. Understand that the pancreas has both exocrine and endocrine functions, meaning it has structures that secrete digestive enzymes and others that secrete hormones.
2. Identify the exocrine portion of the pancreas, which consists of pancreatic acini that produce digestive enzymes released into ducts.
3. Recognize that pancreatic ducts, including the main pancreatic (Wirsung) duct, serve as channels for transporting digestive secretions but are not endocrine structures.
4. Focus on the endocrine portion, which is made up of clusters of cells called pancreatic islets (islets of Langerhans) that secrete hormones like insulin and glucagon directly into the bloodstream.
5. Conclude that the pancreatic islets (islets of Langerhans) form the endocrine portion of the pancreas, distinguishing them from the exocrine acini and ducts.