AEMCA Practice Exam

What effect does cortisol have on the body?

1. Decreases glucose synthesis.

2. Reduces protein breakdown.

3. Increases blood vessel sensitivity to catecholamines.

4. Increases energy expenditure drastically.

The correct answer is: Increases blood vessel sensitivity to catecholamines.

Cortisol is a glucocorticoid hormone produced by the adrenal glands, and one of its key roles is to help the body manage stress. One of the significant effects of cortisol is that it increases the sensitivity of blood vessels to catecholamines, such as adrenaline. This ensures that during stress responses, the body's ability to respond to catecholamines is enhanced, allowing for more effective increases in heart rate, blood flow, and overall metabolic response. By enhancing vascular sensitivity to catecholamines, cortisol ensures that the physiological responses required during stressful situations, like increased energy and alertness, can occur more efficiently. This is vital for the body's fight-or-flight response, where rapid changes in blood flow and energy availability are needed. Understanding this mechanism helps clarify why other options are less accurate. Cortisol does not decrease glucose synthesis; rather, it promotes gluconeogenesis in the liver, increasing glucose availability. Additionally, cortisol does not reduce protein breakdown but instead often leads to increased protein catabolism as part of its role in providing amino acids for gluconeogenesis. Lastly, while cortisol can affect metabolism, it does so in a manner that primarily preserves energy rather than drastically increase energy expenditure, which is not its primary function.