Question

Pancreatic hormones regulate blood glucose level in our body. The hormones that involve in this regulation are glucagon and insulin.
Explain the negative feedback regulation of the secretion of glucagon and insulin.

Answer 1

- Blood glucose level is maintained within the normal range by the action of pancreatic hormones insulin and glucagon.

- Insulin is secreted by beta cells of pancreas and it decreases the blood glucose level. Glucagon is secreted by alpha cells of pancreas and it increases the blood glucose level. Thus, the action of insulin and glucagon are opposite to each other and blood glucose level is maintained within the normal range by a negative feedback mechanism of the secretion of insulin and glucagon.

- In negative feedback regulation, an increase in concentration of a substance causes feedback which finally decreases the concentration of that substance and a decrease in the concentration of a substance causes feedback mechanism which finally increases the concentration of that substance.

- When the blood glucose level is high, insulin is secreted by the beta cells of pancreas which helps the cells (mainly skeletal muscles, adipose tissue, liver) to utilize glucose and also causes hepatocytes (liver cells) to store glucose in the form of glycogen which ultimately decreases the blood glucose level.

- When the blood glucose level is low, alpha cells of pancreas secrete glucagon which breaks down the stored glycogen of liver into glucose and increases the blood glucose level.