What physiological responses are associated with the activation of the Sympathetic Nervous System?

The activation of the Sympathetic Nervous System (SNS) is commonly associated with the body's "fight or flight" response to perceived threats or stressors. When the SNS is activated, several physiological changes occur to prepare the body for immediate action.

One of the key responses is an increase in heart rate, which allows for more blood to be pumped throughout the body, supplying vital organs and muscles with the oxygen and nutrients they need to respond swiftly. Additionally, the pupils dilate to enhance vision and improve the ability to detect and react to potential dangers. This combination of increased heart rate and dilated pupils underscores the body’s preparation for rapid response.

In contrast, options about heart rate slowing, digestion starting, pupils constricting, and relaxation of muscle tension reflect the activities of the Parasympathetic Nervous System, which promotes a state of rest and recovery rather than the alert state associated with sympathetic activation. Understanding these differences is essential in recognizing how the body responds to stress and the physiological changes that occur with SNS activation.