Review Question - QID 109030

This patient likely has type II diabetes mellitus, which is primarily caused by defects of insulin signaling. Insulin is produced in the pancreatic islets of Langerhans by beta cells, which are the cells arranged centrally around the capillaries.

This patient presents with symptoms of polydipsia (increased thirst), polyphagia (increased appetite), and polyuria (increased urination), which are the hallmark signs of diabetes mellitus (DM). The primary hormone derangement in type 2 DM is a lack of response to insulin. The cells that produce insulin are pancreatic beta cells, which are located centrally in the islets of Langerhans close to the capillaries. Type 2 DM is characterized by insulin resistance, while type 1 DM is characterized by autoimmune destruction of the beta cells.

Illustration A shows the completed diagram of the islets of Langerhans and surrounding pancreatic tissue. It demonstrates the locations of all the cells.

Incorrect Answers:
Answer 1: These are the alpha cells that secrete glucagon. They are located mostly on the periphery of the islet further away from the capillaries. Though glucagon is involved in diabetes, it is not the primary hormone responsible for the pathogenesis of diabetes.

Answer 3: These are the delta cells that produce somatostatin. Somatostatin is involved in the regulation of insulin and glucagon but is not the primary hormone involved in diabetes.

Answer 4: These are the exocrine pancreatic glands that are responsible for the production of enzymes involved in digestion like lipases and proteases. The islets of Langerhans make up the endocrine pancreas.

Answer 5: These are the F cells (or PP cells) that secrete pancreatic polypeptide. It is largely involved in the self-regulation of pancreatic enzyme production and does not play a major role in diabetes.

Bullet summary:
Insulin is produced by the beta cells of the pancreas, which are arranged centrally around capillaries in the islets of Langerhans.