Emergency Medical Technician (EMT) Intermediate Practice Exam

Which system initiates the physiological response to stress?

1. Parasympathetic nervous system

2. Sympathetic nervous system

3. Endocrine system

4. Central nervous system

The correct answer is: Sympathetic nervous system

The sympathetic nervous system is responsible for initiating the physiological response to stress, commonly referred to as the "fight or flight" response. When a person experiences stress, the sympathetic nervous system activates quickly and prepares the body to confront or flee from the perceived threat. This system triggers various physiological changes, such as increased heart rate, elevated blood pressure, and enhanced respiratory rate, all aimed at providing the body with a burst of energy and alertness. While other systems mentioned play important roles in the body's overall response to stress, they do not initiate the immediate physiological changes. For instance, the parasympathetic nervous system works to calm the body down after a stress response. The endocrine system, although it releases hormones that can modulate stress responses over a longer period, does not directly initiate the fight or flight response. The central nervous system is involved in processing the stressor and coordinating the response, but the specific physiological changes are driven chiefly by the sympathetic nervous system's rapid activation. Thus, recognizing the role of the sympathetic nervous system is crucial for understanding how the body reacts in high-pressure situations.