Certified Surgical Technologist (CST) Practice Exam

The islets of Langerhans secrete?

1. Bile

2. Insulin

3. Intrinsic factor

4. Inhibiting hormones

The correct answer is: Insulin

The islets of Langerhans are specialized clusters of cells located in the pancreas that play a crucial role in glucose metabolism and regulation. The primary function of these cells is to secrete hormones, with insulin being one of the most significant. Insulin is a hormone that helps lower blood glucose levels by facilitating the uptake of glucose by cells and promoting the storage of glucose as glycogen in the liver. This process is vital in maintaining normal blood sugar levels and enabling the body to use glucose for energy. Other options refer to substances secreted by different organs or types of cells: Bile is produced by the liver and is essential for digestion, especially in emulsifying fats. Intrinsic factor, which is secreted by the stomach lining, is necessary for the absorption of vitamin B12, an essential nutrient for red blood cell production and neurological function. Inhibiting hormones are secreted by the hypothalamus and play a role in regulating the release of hormones from the anterior pituitary gland. Thus, the secretion of insulin by the islets of Langerhans is fundamental to the body's metabolic processes, highlighting why the correct answer is insulin.