NLN Science Practice Exam 2025 – Complete Prep Guide

Cortisol plays a critical role in the body's response to stress, which is primarily related to its influence on metabolism. During stressful situations, cortisol acts to increase energy availability by ensuring that glucose and fatty acids are readily accessible for use by the body. This hormone stimulates gluconeogenesis, the process where glucose is produced from non-carbohydrate sources, leading to an increase in blood sugar levels. Additionally, cortisol facilitates the breakdown of fats and proteins to provide energy. These metabolic adjustments are essential for helping the body manage stress conditions, making it vital for short-term stress response and maintaining homeostasis.

The other options do not accurately capture cortisol’s role during stress. For instance, while cortisol affects immune function, it does so by modulating and, in some cases, suppressing excessive immune responses rather than promoting them. Additionally, cortisol does not decrease glucose levels; instead, it is known for increasing them to ensure that there is enough energy available during times of stress. Lastly, cortisol certainly has a physiological role, as it is instrumental in the stress response and other bodily functions, so the notion that it has no role is incorrect.