Which hormone, produced by the pancreas, plays a key role in regulating blood glucose levels by facilitating glucose uptake into cells and promoting its storage as glycogen in the liver and muscles?

The HbA1c test measures the average blood glucose level over the past 2-3 months and provides information about long-term glucose control. It is commonly used to monitor diabetes management and assess the effectiveness of treatment.

Incorrect choices:

a. This choice is incorrect. The fasting blood glucose test measures blood glucose levels after an overnight fast and provides information about current glucose levels, not long-term control.

b. This choice is incorrect. The OGTT measures the body's ability to clear glucose from the blood and is used to diagnose diabetes and impaired glucose tolerance, but it is not typically used for assessing long-term glucose control.

d. This choice is incorrect. The C-peptide test is used to assess insulin production by the pancreas and is not typically used to assess long-term glucose control.

The liver plays a central role in blood glucose regulation by releasing glucose into the bloodstream through glycogenolysis and gluconeogenesis when blood glucose levels are low. It also stores glucose as glycogen and responds to insulin and glucagon signals.

Incorrect choices:

b. This choice is incorrect. While the kidneys play a role in filtering blood and excreting waste products, they are not primarily responsible for regulating blood glucose levels.

c. This choice is incorrect. The lungs are involved in oxygen and carbon dioxide exchange and are not directly involved in blood glucose regulation.

d. This choice is incorrect. The spleen is involved in immune function and blood filtration, but it does not play a central role in blood glucose regulation.