Optometry Admission Test (OAT) Practice

What does glucagon do in the body?

1. Suppresses insulin production

2. Converts glucose to glucagon in the liver

3. Increases blood glucose from the pancreas

4. Decreases blood glucose levels

The correct answer is: Increases blood glucose from the pancreas

Glucagon is a hormone produced by the alpha cells of the pancreas that plays a crucial role in glucose metabolism and homeostasis. Its primary function is to raise blood glucose levels when they fall too low. When blood glucose levels decrease, glucagon is released into the bloodstream, where it signals the liver to convert stored glycogen back into glucose through a process known as glycogenolysis. This process increases the availability of glucose in the bloodstream for use by the body, particularly for energy-demanding organs. Additionally, glucagon can also promote gluconeogenesis, which is the synthesis of glucose from non-carbohydrate sources. This further contributes to elevating blood glucose levels to maintain adequate energy supply, especially between meals or during periods of fasting. In contrast, the other options do not accurately reflect glucagon's primary role. The first option implies that glucagon suppresses insulin production, which doesn't encompass the full essence of its function. Insulin and glucagon work in opposition, but glucagon doesn't directly suppress insulin; rather, it complements its action during hypoglycemic states. The second option incorrectly states that glucagon converts glucose to glucagon, which is a misunderstanding of how these hormones function. Lastly, the option indicating that glucagon decreases blood