Question

Which statements correctly describe the mechanism of maintaining a normal blood glucose level? (select all that apply)

Without eating for several hours, the pancreas releases glucagon in response to decreased glucose levels.

Without eating for several hours, the pancreas releases glucagon in response to increased glucose levels.

After eating a candy bar, glucagon is released from the pancreas in response to rising glucose levels.

After eating a candy bar, insulin is released from the pancreas in response to rising glucose levels.

Answer 1

The below two statements describe the mechanism of maintaining a normal blood glucose level.

Without eating for several hours, the pancreas releases glucagon in response to decreased glucose levels.

Glucagon is secreted and released by alpha cells of islets of Langerhans of the pancreas. It is a peptide hormone whose major role is to regulate the blood glucose levels. Glucagon is secreted only when the blood glucose level in the body decreases below normal levels. Thus the above mentioned fasting condition triggers glucagon production in pancreas.

It triggers gluconeogenesis, a catabolic pathway by which glucose is produced to reach back to normal blood glucose levels.

After eating a candy bar, insulin is released from the pancreas in response to rising glucose levels

Similarly when a candy bar is ingested and digested it tends to increase the blood sugar level immediately. This is where insulin plays its role.

Insulin is another peptide hormone that is secreted by beta cells of the pancreas. Insulin triggers glycogenesis, which converts glucose in blood to branched complex glycogen and stored in liver and muscles.

These two hormones keep the blood glucose levels at check by regulating them by a feedback mechanism. Thus glucagon is triggered and released only when glucose levels are low that is when a fasting condition leads to decreased levels and not increased levels. Similarly only insulin and not glucagon is produced only when glucose levels rise.