Which hormone is secreted by the Beta cells of the Islets of Langerhans of the pancreas?

1. A

   Glucagon

   Option (a) claims that glucagon is the hormone secreted by the Beta cells. However, glucagon is actually secreted by the Alpha cells of the Islets of Langerhans, which play an opposing role in blood sugar regulation.

2. B

   Insulin

   Option (b) claims that insulin is secreted by the Beta cells of the Islets of Langerhans of the pancreas. This is the correct option because insulin is a vital peptide hormone produced specifically by pancreatic beta cells to lower blood glucose levels by facilitating cellular uptake.

3. C

   Adrenaline

   Option (c) claims that adrenaline is the hormone secreted by these cells. In reality, adrenaline is released by the adrenal medulla in response to stress or emergency situations, not by the pancreas.

4. D

   Aldosterone

   Option (d) claims that aldosterone is secreted by the Beta cells. Aldosterone is a mineralocorticoid steroid hormone produced by the zona glomerulosa of the adrenal cortex to regulate sodium and potassium balance.

Summary. Official key is (b) Insulin. The pancreas contains endocrine regions known as the Islets of Langerhans, comprising different cell types with distinct endocrine functions. Alpha cells produce glucagon, while Beta cells are exclusively responsible for synthesizing and secreting insulin. Misidentifying the source cells of pancreatic hormones is a frequent point of confusion in physiology questions. Therefore, option (b) is the accurate and comprehensive choice.