What is the primary function of the sympathetic nervous system during a fight-or-flight response?

The sympathetic nervous system plays a crucial role in the fight-or-flight response, which is the body's automatic reaction to perceived threats or stressors. When this system is activated, it prepares the body to confront or flee from danger. The primary function is to increase energy mobilization, which involves a range of physiological changes.

During this response, the sympathetic nervous system stimulates the release of adrenaline (epinephrine) and norepinephrine, hormones that help to boost the body’s energy supplies. This leads to an increase in heart rate, elevation of blood pressure, and enhancement of blood flow to the muscles, all of which are necessary for quick physical action. Additionally, energy stores such as glycogen are broken down into glucose, providing immediate fuel to the muscles.

In contrast, other options such as decreasing heart rate, enhancing digestive processes, or promoting relaxation do not align with the sympathetic nervous system's role in stress responses. Instead, these functions are primarily associated with the parasympathetic nervous system, which is responsible for rest and digestion when the body is in a non-stressed state. Therefore, the choice that reflects the primary role of the sympathetic nervous system during a fight-or-flight response is to increase energy mobilization.