AEMCA Practice Exam

What is glucagon and how does it function in the body?

1. It is a steroid hormone that decreases blood glucose levels

2. It is a peptide hormone that increases glucose in the bloodstream

3. It is a carbohydrate that provides immediate energy

4. It is a vitamin that helps in fat absorption

The correct answer is: It is a peptide hormone that increases glucose in the bloodstream

Glucagon is a peptide hormone produced by the alpha cells of the pancreas. Its primary function is to increase glucose levels in the bloodstream, especially during times when the body needs more energy, such as between meals or during physical activity when blood sugar levels may drop. When blood glucose levels fall, glucagon is secreted into the bloodstream, where it acts predominantly on the liver. In the liver, glucagon stimulates gluconeogenesis, which is the process of generating glucose from non-carbohydrate sources, as well as glycogenolysis, the breakdown of glycogen into glucose, which can then be released into the bloodstream. This increase in glucose availability ensures that the body's cells have the necessary energy to function, particularly important for brain and muscle cells. Understanding the role of glucagon is crucial in the context of maintaining energy balance and regulating blood sugar, particularly in conditions such as diabetes where glucagon levels and action can be altered. The other options do not accurately describe glucagon's nature or functions; for instance, glucagon is not a steroid hormone, a carbohydrate, or a vitamin, nor does it play a role in fat absorption.