Which physiological change occurs during stress response?

During a stress response, the body activates the sympathetic nervous system, leading to a series of physiological changes commonly referred to as the "fight or flight" response. One of the primary changes is an increased heart rate. This elevated heart rate serves to pump more blood to vital organs and muscles, preparing the body to respond quickly to perceived threats. Increased blood flow enhances physical performance and alertness, which are crucial during stressful situations.

In contrast, other options do not align with the typical physiological changes associated with stress. For instance, decreased breathing rate and decreased body temperature are not characteristic of a stress response; instead, breathing rates typically increase to supply more oxygen to the body. Additionally, increased stress often leads to a decrease in appetite rather than an increase, as the body's focus shifts to survival instead of digestion. The physiological adjustments made during stress result in heightened alertness and readiness to confront challenges, with an increased heart rate being a key component of that response.